27354 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

ENVIRONMENTAL PROTECTION section 18 of the WIPP Land B. Performance Assessment: Modeling and AGENCY Withdrawal Act of 1992 (Pub. L. 102– Containment Requirements (§§ 194.14, 579), as amended by the WIPP LWA 194.23, 194.31 through 194.34) Amendments (Pub. L. 104–201). 1. Introduction 40 CFR Part 194 2. Human Intrusion Scenarios FOR FURTHER INFORMATION CONTACT [FRLÐ6014±9] : (a) Introduction Betsy Forinash, Scott Monroe, or Sharon (b) Spallings RIN 2060±AG85 White; telephone number (202) 564– (c) Air Drilling 9310; address: Radiation Protection (d) Fluid Injection Criteria for the Certification and Division, Center for the Waste Isolation (e) Potash Mining Recertification of the Waste Isolation Pilot Plant, Mail Code 6602–J, U.S. (f) Carbon Dioxide Injection Pilot Plant's Compliance With the Environmental Protection Agency, 401 (g) Other Drilling Issues 3. Geological Scenarios and Disposal Disposal Regulations: Certification M Street S.W., Washington, DC 20460. Decision System Characteristics For copies of the Compliance (a) Introduction AGENCY: Environmental Protection Application Review Documents (b) WIPP Geology Overview Agency. supporting today’s action, contact Scott (c) Rustler Recharge (d) Dissolution ACTION: Final rule. Monroe. The Agency is also publishing a document, accompanying today’s (e) Presence of Brine in the Salado SUMMARY: The Environmental Protection action, which responds in detail to (f) Gas Generation Model Agency (‘‘EPA’’) is certifying that the significant public comments that were (g) Two-Dimensional Modeling of Brine Department of Energy’s (‘‘DOE’’) Waste and Gas Flow received on the proposed certification (h) Earthquakes Isolation Pilot Plant (‘‘WIPP’’) will decision. This document, entitled (i) Conclusion comply with the radioactive waste ‘‘Response to Comments,’’ may be 4. Parameter Values disposal regulations set forth at obtained by contacting Sharon White at (a) Introduction Subparts B and C of 40 CFR Part 191 the above phone number and address. (b) Distribution Coefficient (Kd) (Environmental Standards for the Copies of these documents are also (c) Actinide Solubility Management and Disposal of Spent available for review in the Agency’s Air (d) Brine Pockets Nuclear Fuel, High-Level and Docket A–93–02. (e) Permeability of Borehole Plugs 5. Other Performance Assessment Issues Transuranic Radioactive Waste). The SUPPLEMENTARY INFORMATION: EPA is required to evaluate whether the (a) Sensitivity Analysis Table of Contents (b) Performance Assessment Verification WIPP will comply with EPA’s standards Test I. What is the WIPP? for the disposal of radioactive waste by 6. Conclusions the WIPP Land Withdrawal Act II. What is the purpose of today’s action? III. With which regulations must the WIPP C. General Requirements (‘‘LWA’’) of 1992, as amended. EPA’s comply? 1. Quality Assurance (§ 194.22) certification of compliance allows the IV. What is the decision on whether the 2. Waste Characterization (§ 194.24) emplacement of radioactive waste in the WIPP complies with EPA’s regulations? 3. Future State Assumptions (§ 194.25) WIPP to begin, provided that all other A. Certification Decision 4. Expert Judgment (§ 194.26) applicable health and safety standards, B. Conditions 5. Peer Review (§ 194.27) and other legal requirements, have been C. Land Withdrawal Act Section 4(b)(5)(B) D. Assurance Requirements Leases 1. Active Institutional Controls (§ 194.41) met. The certification constitutes final 2. Monitoring (§ 194.42) approval under the WIPP LWA for D. EPA’s Future Role at the WIPP (recertification, enforcement of 3. Passive Institutional Controls (§ 194.43) shipment of transuranic waste from conditions) 4. Engineered Barriers (§ 194.44) specific waste streams from Los Alamos V. What information did EPA examine to 5. Consideration of the Presence of National Laboratory for disposal at the make its decision? Resources (§ 194.45) WIPP. However, the certification is VI. In making its final decision, how did EPA 6. Removal of Waste (§ 194.46) subject to four specific conditions, most incorporate public comments on the E. Individual and Ground-water Protection notably that EPA must approve site- proposed rule? Requirements (§§ 194.51–55) specific waste characterization measures A. Introduction and the Role of Comments IX. Does DOE need to buy existing oil and gas leases near the WIPP? and quality assurance programs before in the Rulemaking Process B. Significant Changes Made to the Final X. Why and how does EPA regulate the other waste generator sites may ship Rule in Response to Comments WIPP? waste for disposal at the WIPP. The VII. How did EPA respond to general A. The WIPP Land Withdrawal Act Agency is amending the WIPP comments on its proposed certification B. Limits of EPA’s Regulatory Authority at compliance criteria (40 CFR Part 194) by decision? the WIPP adding Appendix A that describes VIII. How did EPA respond to major C. Compliance with Other Environmental EPA’s certification, incorporating the technical issues raised in comments? Laws and Regulations approval processes for waste generator A. Content of Compliance Certification XI. How has the public been involved in sites to ship waste for disposal at the Application (§ 194.14) EPA’s WIPP activities? A. Public Involvement Prior to Proposed WIPP, and adding a definition for 1. Site Characterization and Disposal System Design Rule ‘‘Administrator’s authorized (a) Shaft Seals B. Proposed Certification Decision representative.’’ Finally, EPA is (b) Panel Closure System C. Public Hearings on Proposed Rule finalizing its decision, also pursuant to 2. Results of Assessments, Input D. Additional Public Input on the Proposed the WIPP LWA, that DOE does not need Parameters to Performance Assessments, Rule to acquire existing oil and gas leases Assurance Requirements, and Waste E. Final Certification Decision, Response to near the WIPP to comply with the Acceptance Criteria Comments Document disposal regulations. 3. Background Radiation, Topographic F. Dockets Maps, Past and Current Meteorological XII. How will the public be involved in EFFECTIVE DATE: This decision is Conditions EPA’s future WIPP activities? effective June 17, 1998. A petition for 4. Other Information Needed for XIII. Where can I get more information about review of this final action must be filed Demonstration of Compliance EPA’s WIPP activities? no later than July 17, 1998, pursuant to 5. Conclusion A. Technical Support Documents Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27355

B. WIPP Information Line, Mailing List, across the United States, including and clarify the basis on which EPA’s and Internet Homepage locations in Colorado, Idaho, New certification decision is made. XIV. Regulatory Analysis/Administrative Mexico, Nevada, Ohio, South Carolina, IV. What Is the Decision on Whether Requirements Tennessee, and Washington. Much of A. Executive Order 12866 the WIPP Complies With EPA’s the waste proposed for disposal at the B. Regulatory Flexibility Regulations? C. Paperwork Reduction Act WIPP will be generated in the future. A. Certification Decision D. Unfunded Mandates Reform Act II. What Is the Purpose of Today’s E. Executive Order 12898 Action? The EPA finds that DOE has F. Small Business Regulatory Enforcement demonstrated that the WIPP will Fairness Act of 1996 Before disposal of radioactive waste comply with EPA’s radioactive waste G. National Technology Transfer & can begin at the WIPP, the U.S. Advancement Act of 1995 disposal regulations at Subparts B and Environmental Protection Agency C of 40 CFR Part 191. This decision H. Executive Order 13045—Children’s (‘‘EPA,’’ or ‘‘the Agency’’) must certify Health Protection allows the WIPP to begin accepting that the WIPP facility will comply with transuranic waste for disposal, provided I. What is the WIPP? EPA’s radioactive waste disposal that other applicable environmental regulations (Subparts B and C of 40 CFR The Waste Isolation Pilot Plant 3 regulations have been met and once a (‘‘WIPP’’) is a potential disposal system Part 191). The purpose of today’s action 30-day Congressionally-required waiting for radioactive waste. Developed by the is to issue EPA’s certification decision. period has elapsed.4 EPA’s decision is Department of Energy (‘‘DOE’’ or ‘‘the With today’s action, EPA will add to based on a thorough review of Department’’), the WIPP is located near the Code of Federal Regulations a new information submitted by DOE, Carlsbad in southeastern New Mexico. Appendix A to 40 CFR Part 194 independent technical analyses, and The DOE intends to bury radioactive describing EPA’s certification decision public comments. The EPA determined waste 2150 feet underground in an and the conditions that apply to the that DOE met all of the applicable ancient layer of salt which will certification. The Agency is adding a requirements of the WIPP compliance eventually ‘‘creep’’ and encapsulate new section, § 194.8, to the WIPP criteria at 40 CFR Part 194. However, as waste containers. The WIPP has a total compliance criteria (40 CFR Part 194) discussed below, DOE must meet capacity of 6.2 million cubic feet of that describes the processes EPA will certain conditions in order to maintain waste. use to approve quality assurance and a certification for the WIPP and before Congress authorized the development waste characterization programs at shipping waste for disposal at the WIPP. and construction of the WIPP in 1980 waste generator sites. The EPA is also B. Conditions ‘‘for the express purpose of providing a adding a definition of the term research and development facility to ‘‘Administrator’s authorized As noted above, EPA determined that demonstrate the safe disposal of representative’’ to the WIPP compliance DOE met all of the applicable radioactive wastes resulting from the criteria. Except for these actions, the requirements of the WIPP compliance defense activities and programs of the certification decision does not otherwise criteria. In several instances, however, United States.’’ 1 The waste which may amend or affect EPA’s radioactive waste EPA found that it is necessary for DOE be emplaced in the WIPP is limited to disposal regulations or the WIPP to take additional steps to ensure that transuranic (‘‘TRU’’) radioactive waste compliance criteria. the measures actually implemented at generated by defense activities Today’s action also addresses the the WIPP (and thus the circumstances associated with nuclear weapons; no provision of section 7(b)(2) of the WIPP expected to exist there) are consistent high-level waste or spent nuclear fuel Land Withdrawal Act which prohibits with DOE’s compliance certification from commercial power plants may be DOE from emplacing transuranic waste application (‘‘CCA’’) and with the basis disposed of at the WIPP. TRU waste is underground for disposal at the WIPP for EPA’s compliance certification. defined as materials containing alpha- until, inter alia, it acquires specified oil Regarding several requirements, DOE emitting radio-isotopes, with half lives and gas leases, unless EPA determines demonstrated compliance with the greater than twenty years and atomic that such acquisition is not necessary. applicable compliance criteria for only numbers above 92, in concentrations III. With Which Regulations Must the one category of waste at a single waste greater than 100 nano-curies per gram of WIPP Comply? generator site. To address these waste.2 situations, EPA is amending the WIPP Most TRU waste proposed for The WIPP must comply with EPA’s compliance criteria, 40 CFR Part 194, disposal at the WIPP consists of items radioactive waste disposal regulations, and appending four explicit conditions that have become contaminated as a located at Subparts B and C of 40 CFR to its certification of compliance for the result of activities associated with the Part 191. These regulations limit the WIPP. production of nuclear weapons (or with amount of radioactive material which Condition 1 of the certification relates the clean-up of weapons production may escape from a disposal facility, and to the panel closure system, which is facilities), e.g., rags, equipment, tools, protect individuals and ground water intended over the long term to block protective gear, and organic or inorganic resources from dangerous levels of brine flow between waste panels in the sludges. Some TRU waste is mixed with radioactive contamination. In addition, WIPP. In its CCA, DOE presented four hazardous chemicals. Some of the waste the compliance certification application options for the design of the panel proposed for disposal at the WIPP is (‘‘CCA’’) and other information closure system, but did not specify currently stored at Federal facilities submitted by DOE must meet the which one would be constructed at the requirements of the WIPP compliance WIPP. The EPA based its certification 1 Department of Energy National Security and criteria at 40 CFR Part 194. The decision on DOE’s use of the most Military Applications of Nuclear Energy compliance criteria implement and robust design (referred to in the CCA as Authorization Act of 1980, Pub. L. 96–164, section interpret the general disposal ‘‘Option D’’). The Agency found the 213. regulations specifically for the WIPP, 2 WIPP Land Withdrawal Act, Pub. L. 102–579, Option D design to be adequate, but also section 2(18), as amended by the 1996 WIPP LWA Amendments, Pub. L. 104–201. 3 WIPP LWA, section 8(d). 4 WIPP LWA, § 7(b). 27356 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations determined that the use of a Salado incorporated into the body of the WIPP C. Land Withdrawal Act Section mass concrete—using brine rather than compliance criteria, in a new section at 4(b)(5)(B) Leases fresh water—would produce concrete § 194.8. (For more information on this The EPA finds that DOE does not seal permeabilities in the repository change, see the preamble section need to acquire existing oil and gas more consistent with the values used in entitled, ‘‘Significant Changes to the leases (Numbers NMNM 02953 and DOE’s performance assessment. Final Rule Made in Response to Public 02953C) (referred to as the ‘‘section Therefore, Condition 1 of EPA’s Comments.’’ For further discussion of 4(b)(5)(B) leases’’) in the vicinity of the certification requires DOE to implement Conditions 2 and 3, refer to the WIPP in order to comply with EPA’s the Option D panel closure system at the preamble discussions of § 194.22 and final disposal regulations at 40 CFR Part WIPP, with Salado mass concrete § 194.24, respectively.) 191, Subparts B and C. The EPA replacing fresh water concrete. (For concludes that potential activities at more detail on the panel closure system, Condition 4 of the certification relates these existing leases would have an refer to the preamble discussion of to passive institutional controls insignificant effect on releases of § 194.14.) (‘‘PICs’’). The WIPP compliance criteria Conditions 2 and 3 of the final rule require DOE to use both records and radioactive material from the WIPP disposal system and, thus, that they do relate to activities conducted at waste physical markers to warn future not cause the WIPP to violate the generator sites that produce the societies about the location and contents disposal regulations. transuranic waste proposed for disposal of the disposal system, and thus to deter in the WIPP. The WIPP compliance inadvertent intrusion into the WIPP. D. EPA’s Future Role at the WIPP criteria (§§ 194.22 and 194.24) require (§ 194.43) In its application, DOE (recertification, enforcement of DOE to have in place a system of provided a design for a system of PICs, conditions) controls to measure and track important but stated that many aspects of the The EPA will continue to have a role waste components, and to apply quality design would not be finalized for many at the WIPP after this certification assurance (‘‘QA’’) programs to waste years (even up to 100) after closure. The becomes effective. As discussed above, characterization activities. At the time PICs actually constructed and placed in of EPA’s proposed certification DOE must submit periodic reports on decision, the Los Alamos National the future must be consistent with the any activities or conditions at the WIPP Laboratory (‘‘LANL’’) was the only site basis for EPA’s certification decision. that differ significantly from the to demonstrate the execution of the Therefore, Condition 4 of the information contained in the most required QA programs and the certification requires DOE to submit a recent compliance application. The EPA implementation of the required system revised schedule showing that markers may also, at any time, request additional of controls. Therefore, EPA’s and other measures will be information from DOE regarding the certification constitutes final approval implemented as soon as possible after WIPP. (§ 194.4) The Agency will review under the WIPP LWA for DOE to ship closure of the WIPP. The DOE also must such information as it is received to waste for disposal at the WIPP only provide additional documentation determine whether the certification from the LANL, and only for the showing that it is feasible to construct must be modified, suspended, or retrievably stored (legacy) debris at markers and place records in archives as revoked. Such action might be LANL for which EPA has inspected and described in DOE’s certification warranted if, for example, significant information contained in the most approved the applicable system of application. After closure of the WIPP, recent compliance application were no controls. Before DOE may ship any DOE will not be precluded from mixed (hazardous and radioactive) longer to remain true. The certification implementing additional PICs beyond could be modified to alter the terms or waste from the LANL—even if it is those described in the application. (See encompassed by the waste streams conditions of certification—for example, the preamble discussion of § 194.43 for to add a new condition, if necessary to approved by EPA in this action—DOE more information on PICs.) must obtain any other regulatory address new or changed activities at the approvals that may be needed, Although not specified in the WIPP. (§ 194.2) The certification could including approval from the State of certification, it is a condition of any be revoked if it becomes evident in the New Mexico under the Resource certification that DOE must submit future that the WIPP cannot or will not Conservation and Recovery Act to periodic reports of any planned or comply with the disposal regulations. dispose of such waste at the WIPP. unplanned changes in activities Either modification or revocation must As described in the final WIPP pertaining to the disposal system that be conducted by rulemaking, in certification, before other waste may be differ significantly from the most recent accordance with the WIPP compliance shipped for disposal at the WIPP, EPA compliance application. (§ 194.4(b)(3)) criteria. (§§ 194.65–66) Suspension may must separately approve the QA The DOE must also report any releases be initiated at the Administrator’s programs for other generator sites of radioactive material from the disposal discretion, in order to promptly reverse (Condition 2) and the waste system. (§ 194.4(b)(3)(iii), (v)) Finally, or mitigate a potential threat to public characterization system of controls for EPA may request additional information health. For instance, a suspension would take effect if, during other waste streams (Condition 3). The from DOE at any time. (§ 194.4(b)(2)) approval process includes an emplacement of waste, a release from These reports and information will opportunity for public comment, and an the WIPP occurred in excess of EPA’s allow EPA to monitor the performance inspection (of a DOE audit) or audit of containment limits. (See § 194.4(b)(3).) the waste generator site by EPA. The of the disposal system and evaluate In addition to reviewing annual Agency’s approval of waste whether the certification must be reports from DOE regarding activities at characterization systems of controls and modified, suspended, or revoked for any the WIPP, EPA periodically will QA programs will be conveyed in a reason. (Modifications, suspensions, evaluate the WIPP’s continued letter from EPA to DOE. In response to recertification, and other activities are compliance with the WIPP compliance public comments on these conditions, also addressed in the preamble section criteria and disposal regulations. As EPA’s approval processes for waste entitled, ‘‘EPA’s Future Role at the directed by Congress, this generator site programs have been WIPP.’’) ‘‘recertification’’ will occur every five Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27357 years.5 For recertification, DOE must when DOE submits a revised schedule that DOE satisfied the specific submit to EPA for review the and additional documentation regarding requirements of the criteria in information described in the WIPP the feasibility of implementing passive demonstrating compliance with the compliance criteria (although, to the institutional controls. This disposal regulations. The primary extent that information submitted in documentation must be provided to source of information examined by EPA previous certification applications EPA no later than the final was a compliance certification remains valid, it can be summarized and recertification application. Once application (‘‘CCA’’) submitted by DOE referenced rather than resubmitted). received, the information will be placed on October 29, 1996. (Copies of the CCA (§ 194.14) In accordance with the WIPP in EPA’s docket, and the Agency will were placed in EPA’s Air Docket A–93– evaluate the adequacy of the compliance criteria, documentation of 02, Category II–G.) The DOE submitted continued compliance will be made documentation. If necessary, EPA may additional information after that time. available in EPA’s dockets, and the initiate a modification to the On May 22, 1997, EPA announced that public will be provided at least a 30-day certification to address DOE’s revised period in which to submit comments. schedule; any such modification would DOE’s application was deemed to be The EPA’s decision on recertification be undertaken in accordance with the complete. (62 FR 27996–27998) will be announced in the Federal public participation requirements However, as contemplated by Register. (§ 194.64) described in the WIPP compliance Congress, EPA’s compliance In the immediate future, the Agency criteria, §§ 194.65–66. During the certification decision is based on more expects to conduct numerous operational period when waste is being than the complete application. The EPA inspections at waste generator sites in emplaced in the WIPP (and before the also relied on materials prepared by the order to implement Conditions 2 and 3 site has been sealed and Agency or submitted by DOE in of the compliance certification. Notices decommissioned), EPA will verify that response to EPA requests for specific announcing EPA inspections or audits specific actions identified by DOE in the additional information necessary to to evaluate implementation of quality CCA and supplementary information address technical sufficiency concerns. assurance (‘‘QA’’) and waste (and in any additional documentation The Agency also considered public submitted in accordance with Condition characterization requirements at comments on the proposed rule which generator facilities will be published in 4) are being taken to test and implement supported or refuted technical the Federal Register. The public will passive institutional controls. For positions. Thus, EPA’s certification have the opportunity to submit written example, DOE stated that it will submit comments on the waste characterization a plan for soliciting archives and record decision is based on the entire record and QA program plans submitted by centers to accept WIPP information in available to the Agency, which is DOE. As noted above, EPA’s decisions the fifth recertification application. The contained in EPA’s Air Docket A–93–02. on whether to approve waste generator Agency can confirm implementation of The record consists of the complete QA program plans and waste such measures by examining CCA, supplementary information characterization systems of controls— documentation and by conducting submitted by DOE in response to EPA and thus, to allow shipment of specific inspections under its authority at requests for additional information, waste streams for disposal at the § 194.21. technical reports generated by EPA and WIPP—will be conveyed by a letter from Finally, the WIPP compliance criteria EPA contractors, EPA audit and EPA to DOE. A copy of the letter, as provide EPA the authority to conduct inspection reports, and public well as any EPA inspection or audit inspections of activities at the WIPP and comments submitted on EPA’s proposed reports, will be placed in EPA’s docket. at all off-site facilities which provide certification decision during the public (See the preamble sections entitled information included in certification comment period. applications. (§ 194.21) The Agency ‘‘Dockets’’ and ‘‘Where can I get more In response to public comments information about EPA’s WIPP expects to conduct periodic inspections, both announced and unannounced, to regarding the precise materials EPA activities?’’ for more information considered in reaching its certification regarding EPA’s rulemaking docket.) verify the adequacy of information decision, the Compliance Application The procedures for EPA’s approval have relevant to certification applications. Review Documents (‘‘CARDs’’) been incorporated in the compliance The Agency may conduct its own criteria at a new section, § 194.8. laboratory tests, in parallel with those supporting today’s decision reference As discussed previously, Condition 1 conducted by DOE. The Agency also the relevant portion(s) of the October 29, of the WIPP certification requires DOE may inspect any relevant records kept 1996, CCA and any supplementary to implement the Option D panel by DOE, including those records information that the Agency relied on in closure system at the WIPP, with Salado required to be generated in accordance reaching a particular compliance mass concrete being used in place of with the compliance criteria. For decision. (Docket A–93–02, Item V–B–2) fresh water concrete. It will be possible example, EPA intends to conduct All materials which informed EPA’s to evaluate the closure system only ongoing inspections or audits at the proposed and final decisions have been when waste panels have been filled and WIPP and at waste generator sites to placed in the WIPP dockets or are are being sealed. At that time, EPA ensure that approved quality assurance otherwise publicly available. A full list intends to confirm compliance with this programs are being adequately of the supporting documentation for condition through inspections under its maintained and documented. The EPA EPA’s certification decision and the authority at § 194.21 of the WIPP plans to place inspection reports in its DOE compliance documentation docket for public examination. compliance criteria. considered by the Agency is located at Similarly, EPA will be able to V. What Information Did EPA Examine Docket A–93–02, Item V–B–1. For evaluate DOE’s compliance with to Make its Decision? further information regarding the Condition 4 of the certification only The EPA made its certification availability of information EPA examined, see the section entitled 5 WIPP LWA, § 8(f). Congress also directed that decision by comparing relevant this periodic recertification ‘‘shall not be subject to information to the WIPP compliance ‘‘Dockets’’ in this preamble. rulemaking or judicial review.’’ criteria (40 CFR Part 194) and ensuring 27358 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

VI. In Making its Final Decision, how B. Significant Changes to the Final Rule controls on the basis of waste streams did EPA Incorporate Public Comments Made in Response to Public Comments or, where multiple waste streams may on the Proposed Rule? Today’s action finalizes EPA’s be characterized by the same waste proposed decision that the WIPP facility characterization processes and A. Introduction and the Role of techniques, groups of waste streams. Comments in the Rulemaking Process will comply with the disposal regulations and that DOE does not need A number of commenters suggested that in the waste generator site approval Congress directed that EPA’s to acquire existing oil and gas leases in the WIPP Land Withdrawal Area. (For process, EPA should delay the public certification decision for the WIPP be comment period until after completion conducted by informal (or ‘‘notice-and- further information, refer to the preamble section entitled, ‘‘What is the of an inspection or audit, and should comment’’) rulemaking pursuant to make the Agency’s approval decision decision on whether the WIPP complies Section 4 of the Administrative explicitly subject to judicial review. with EPA’s regulations?’’) Beyond these Procedure Act (‘‘APA’’).6 Notice-and- Other comments questioned the broad determinations, EPA’s proposed comment rulemaking under the APA authority for, and the value of, a certification decision also included four requires that regulatory agencies separate site approval process by EPA. conditions related to the panel closure provide notice of a proposed The EPA finds that it is both system, quality assurance at waste rulemaking, an opportunity for the necessary and within the Agency’s generator sites, waste characterization public to comment on the proposed authority to evaluate and approve site- measures at waste generator sites, and specific QA and waste characterization rule, and a general statement of the basis passive institutional controls. The final and purpose of the final rule.7 The programs. The compliance criteria rule retains all of these conditions. expressly provide that any certification notice of proposed rulemaking required However, in response to comments by the APA must ‘‘disclose in detail the of compliance ‘‘may include such submitted on the proposal, the Agency conditions as [EPA] finds necessary to thinking that has animated the form of has made clarifying changes to Subpart the proposed rule and the data upon support such certification.’’ (§ 194.4(a)) A of 40 CFR Part 194 to provide a Before waste is shipped for disposal at which the rule is based.’’ (Portland clearer explanation of the process for the WIPP, EPA must be confident that Cement Ass’n v. Ruckelshaus, 486 F.2d determining compliance with the the waste will conform to the waste 375, 392–94 (D.C. Cir. 1973)) The public conditions related to waste generator limits and other waste-related is thus enabled to participate in the sites. assumptions incorporated in DOE’s process by making informed comments Proposed Conditions 2 and 3 relate to performance assessment—that is, that on the Agency’s proposal. This provides quality assurance (‘‘QA’’) programs and DOE adheres to the fundamental the Agency the benefit of ‘‘an exchange waste characterization programs, information and assumptions on the of views, information, and criticism respectively, at waste generator sites waste on which the certification of between interested persons and the intending to ship waste for disposal at compliance is based. Such confidence agency.’’ (Id.) the WIPP. Except for removal of the can be assured only by confirmation procedural sections of the proposed that the required QA and waste For the WIPP certification decision, conditions from the appendix (as there are two primary mechanisms by characterization programs are in place proposed) to Subpart A of 40 CFR Part (i.e., established, implemented or which EPA explains the issues that were 194, to provide for a clearer enunciation raised in public comments and the executed) at waste generator sites. The of the process for determining EPA believes that an approval process Agency’s reactions to them. First, broad compliance with the conditions, these separate from DOE’s internal procedures or major comments are discussed in the conditions are retained with minor is beneficial because DOE’s process is succeeding sections of this preamble. clarifications in the final rule. The not geared solely to confirming that Second, EPA is publishing a document, conditions restrict DOE from shipping programs adhere to EPA’s compliance accompanying today’s action and waste to the WIPP from any sites other criteria, and because DOE’s process does entitled ‘‘Response to Comments,’’ than the Los Alamos National not provide for public participation. which contains the Agency’s response Laboratory until EPA separately Given the great public interest to all significant comments received approves the QA and waste regarding the WIPP, and waste during the comment period on the characterization plans at other waste characterization in particular, EPA proposed certification decision. (The generator sites. For both QA and waste believes it is important that the public EPA also responded to comments characterization programs, the proposed be informed of and have the opportunity received on its advance notice of approval process included: placement to be involved in the site approval proposed rulemaking (‘‘ANPR’’); for in the docket of site-specific process. To that end, EPA’s approval further information on the ANPR, see documentation submitted by DOE, process includes docketing information the preamble section ‘‘Public publication of a Federal Register notice relevant to site-specific approvals, and Involvement Prior to the Proposed by EPA announcing a scheduled allowing the public to comment on such Rule.’’) The Response to Comments inspection or audit, a period of at least information. document provides more detailed 30 days for the public to comment on The EPA’s certification that the WIPP information placed in the docket, and will comply with the 40 CFR Part 191 responses to issues which are addressed the Agency’s written decision regarding radioactive waste disposal regulations is in the preamble, and addresses all other the approval of these programs in the based on the Agency’s determination significant comments on the proposal. form of a letter from EPA to DOE. The that the WIPP will comply with the All comments received by EPA, whether EPA proposed to approve QA programs containment requirements and other written or oral, were given equal on a site-wide basis. However, because requirements of 40 CFR Parts 191 and consideration in developing the final the features of waste streams can vary 194 for the waste inventory described rule. widely and thus can require for purposes of the performance significantly different characterization assessment. In the CCA, DOE purported 6 WIPP LWA, § 8(d)(2). techniques, EPA proposed to approve to demonstrate that the WIPP would 7 5 U.S.C. 553 waste characterization measures and meet the 40 CFR Part 191 release limits Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27359 by modeling the WIPP’s behavior in its Response to Comments for 40 CFR Part Nevertheless, in response to performance assessment. The 194, EPA emphasized that compliance comments requesting changes or performance assessment incorporated with the requirements would be clarifications to EPA’s waste generator certain upper and lower limiting values confirmed through inspections or audits site and waste stream approval of specified waste components, as and would not serve to re-open the processes, EPA made certain changes to required by 40 CFR 194.24(c). The EPA certification rulemaking. (Docket A–92– the proposed conditions. In order to confirmed the results of the 56, Item V–C–1, pp. 6–5, 6–8, and 6–20) clarify EPA’s original intent in the performance assessment using the same The Agency stated that the certification compliance criteria regarding approval upper and lower limiting values in the rulemaking would address DOE’s of site-specific activities, EPA is performance assessment verification test analysis of waste characteristics and amending the compliance criteria at 40 (‘‘PAVT’’). Those upper and lower components and documentation that a CFR Part 194 to include the site-specific limiting values apply to contact- system of controls had been established approval process. (See 62 FR 58804, handled, remote-handled, and to-be- at the WIPP to track the amount of 58815) Thus, the procedures for generated waste from numerous important waste components emplaced demonstrating compliance with the generator sites. Thus, in today’s action, in the disposal system. (Docket A–92– proposed Conditions 2 and 3 are EPA certifies that the WIPP will comply 56, Item V–C–1, p. 6–9) The certification incorporated in the final rule as a new with the 40 CFR Part 191 containment rulemaking has addressed these issues section at 40 CFR Part 194: § 194.8, requirements to the extent that and found DOE in compliance with the ‘‘Approval Process for Waste Shipment emplaced waste falls within the waste requisite criteria. The EPA believes that from Waste Generator Sites for Disposal envelope limits that were shown by the the comprehensive waste at the WIPP.’’ Also, in response to performance assessment, and confirmed characterization approach described by comments advocating greater by the PAVT, to be compliant with the DOE in the CCA—including the transparency in the approval process, 40 CFR Part 191 standards. Proposed approach to identification, limitation, EPA has clarified that scheduled Conditions 2 and 3 change neither the and confirmation of waste components inspections or audits by EPA for the performance assessment assumptions important to containment of waste in purpose of approving quality assurance nor the terms on which the WIPP is the disposal system—is an appropriate programs at waste generator sites will be authorized for disposal, but rather basis for granting an initial certification. announced by notice in the Federal ensure that the assumptions on which The EPA further believes that Register (§ 194.8(a)); this is consistent the compliance certification is based are confirmation of the QA and system of with EPA’s commitment to do so for adhered to in practice. controls at waste generator sites (i.e., inspections and audits of waste Based on public comments, EPA also measuring and tracking important waste characterization programs at generator finds it necessary to clarify that the components) can be reasonably obtained sites (§ 194.8(b)). Providing notice of compliance criteria at § 194.22 and by a process of inspections and audits such inspections will alert the public to § 194.24 were not intended to require in accordance with 40 CFR 194.21, upcoming EPA approval activities and that DOE address their requirements— 194.22(e), and 194.24(h). allow for more informed public including QA measures, and the use of The EPA declines to modify the participation. While public notice will process knowledge—for all waste be provided for the scheduled initial streams in the certification application proposed approval process by delaying the comment period until after the phase of an inspection or audit, should for the initial certification. Clearly, it it prove necessary for EPA to conduct would be impossible to do so for the to- issuance of EPA’s inspection or audit follow-up activities or continuations of be-generated waste. It is similarly report. The EPA does not believe it is inspections and audits, EPA reserves the impossible for DOE to demonstrate prudent to commit to a strict sequence right to do so without providing fully, in the initial certification of events that will be adhered to for additional public notice. Such follow- application, that the waste emplaced in every approval. In some cases, the up activities or continuations of audits the disposal system actually conforms to Agency may place records of a or inspections might be necessary to the waste envelope (i.e., upper and completed inspection or audit in the obtain additional information or ensure lower waste limits) upon which the docket prior to or during the public that corrective actions are being taken to certification is based, since waste comment period. However, in other resolve initial findings. In no case will cannot be disposed of at the WIPP cases, the Agency believes that the before EPA grants an initial public comment period may better serve EPA decide whether to approve site- certification. Confusion on these issues members of the public if it allows them specific quality assurance or waste arose because the compliance criteria at to provide comments on DOE’s characterization programs before 40 CFR Part 194 apply to information in documentation prior to EPA’s providing a minimum 30-day public compliance recertification applications inspection or audit. In this way, public comment period on documentation of as well as the initial certification comments could inform EPA’s the program plans, or before conducting application. inspection criteria and process, or an inspection or audit at the relevant The fact that it was not EPA’s intent provide information on which EPA may site. to require DOE to have implemented QA take action to follow up in the The Agency received some comments or measurement programs for all waste inspection or audit. Therefore, the related to Conditions 1 and 4 in the at every site prior to initial certification Agency does not believe that it is proposed rule. EPA’s responses to these is supported by numerous statements prudent to specify when the comment comments are discussed in the preamble made by the Agency at the time the period may occur in relation to an sections related to § 194.14 and compliance criteria were issued. The inspection or audit. Furthermore, EPA § 194.43, respectively. Conditions 1 and EPA had great discretion in setting the declines to make any statement 4 were retained without change in the waste characterization requirements, regarding whether the approval final rule. The response to comments since they were part of the general decisions are subject to judicial review. document accompanying today’s action requirements of the WIPP compliance Jurisdiction of U.S. Federal Courts is provides more detailed responses criteria and not derived directly from governed by the enactments of the U.S. regarding the certification conditions the disposal regulations. In the Congress. and all aspects of the final rule. 27360 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

The EPA received no significant other aspects of the WIPP’s operation. In rulemaking. The EPA initially denied comments on its proposed actions to particular, the public was concerned this request because such information is slightly modify the criteria by revising with the risks of transporting typically claimed as confidential the authority citation and adding a new radioactive materials from waste business information by federal definition for Administrator’s generator sites to the WIPP. All government contractors. (The Trade authorized representative. Therefore, transportation requirements for the Secrets Act prohibits EPA from these actions take effect without change WIPP are established and enforced by releasing confidential business from the proposed rule. regulators other than EPA. (For further information, and imposes criminal discussion on the source and limitations liability on federal employees for the VII. How Did EPA Respond to General of EPA’s authority to regulate the WIPP, unauthorized disclosure of such Comments on Its Proposed Certification see preamble Section X, ‘‘Why and how confidential information.9) However, in Decision? does EPA regulate the WIPP?’’) One response to the public interest regarding The EPA received many comments commenter stated that EPA should this issue, EPA sought and obtained which addressed broad issues related to survey electric and magnetic fields at from its contractors a limited waiver of the proposed certification decision. the WIPP. The EPA’s disposal confidentiality to release the names and Many citizens simply expressed their regulations apply only to ionizing qualifications of individual employees strong support for, or opposition to, radiation. They do not apply to non- who provided technical support related opening the WIPP. Some commenters ionizing radiations such as electric and to EPA’s certification decision. In requested that EPA consider certain magnetic fields. These issues are beyond January 1998, EPA provided this factors in making its certification the scope of EPA’s authority to regulate contractor information to several decision. These factors include reviews waste disposal at the WIPP and are not stakeholders and also placed it in the by organizations other than EPA, and addressed in the certification rulemaking docket. (Docket A–93–02, the political or economic motivations of rulemaking. Items IV–C–13 and IV–C–14) The interested parties. The EPA’s The EPA received a number of Agency also sent to stakeholders (and certification decision must be made by comments suggesting that the Agency docketed) a description of the measures comparing the scope and quality of should have provided more or better EPA has taken to ensure that contractors relevant information to the objective opportunities for public participation in do not have any conflict of interest in criteria of 40 CFR Part 194. Where its decision making process. Comments providing technical support on the relevant, the Agency has considered suggested, for example, that EPA should certification rulemaking. While EPA public comments which support or have rescheduled public hearings, agreed to release the above information refute technical positions taken by DOE. responded more fully to comments to allay public concerns, such Emotional pleas and comments on the submitted prior to the proposed rule, information is not relevant to EPA’s motives of interested parties are factors extended the public comment period, certification decision. Under notice-and- that are not relevant to a determination and included the public in all meetings comment rulemaking, it is the substance of whether DOE has demonstrated between EPA and DOE. The EPA and basis for EPA’s decision that are at compliance with the disposal provided numerous opportunities for issue. public participation in the WIPP regulations and the WIPP compliance Finally, several commenters stated certification decision, including two criteria, and are therefore outside the that EPA—by initially certifying the comment periods—one before and one scope of this rulemaking. WIPP to receive only certain waste from A number of commenters suggested after the proposed decision—of at least 120 days (In fact, EPA accepted the Los Alamos National Laboratory—is that EPA should explore alternative granting a piecemeal certification, and methods of waste disposal, such as comments on its advance notice of proposed rulemaking announcing that such an action is illegal under neutralizing radioactive elements, EPA’s regulatory authority. The EPA before proceeding with a certification receipt of DOE’s CCA for over 250 days.), two sets of public hearings in disagrees with the assertion that its decision. Others stated that the WIPP actions constitute a phased certification. should be opened immediately because New Mexico, Federal Register notices, and a number of meetings with various The EPA’s certification is based on the underground burial of radioactive waste Agency’s determination that the WIPP is less hazardous than the current stakeholders. These measures exceed the basic requirements for notice-and- will comply with the disposal strategy of above-ground storage. Such regulations for the inventory described considerations are all outside the scope comment rulemaking and are in full compliance with the public in the performance assessment. of this rulemaking. Congress did not Conditions 2 and 3 of the certification delegate to EPA the authority to participation requirements of both the WIPP compliance criteria and the (related to waste generator sites) change abandon or delay the WIPP in favor of neither the performance assessment other disposal methods. Congress Administrative Procedure Act. Further discussion on the measures taken by assumptions nor the terms on which the mandated that EPA certify, pursuant to WIPP is authorized for disposal, but Section 4 of the APA, whether the WIPP EPA to involve the public can be found in the preamble section entitled, ‘‘How ensure that DOE adheres to the will comply with the radioactive waste assumptions on which compliance is 8 has the public been involved in EPA’s disposal regulations. Thus, EPA is based. The EPA believes this approach obligated to determine whether the WIPP activities?’’ Some members of the public is consistent with Congressional intent WIPP complies with the disposal expressed doubt that EPA and its (as reflected in the WIPP LWA) and regulations, regardless of the relative contractors possessed the necessary with the disposal regulations and risks of underground disposal compared technical skills to evaluate DOE’s compliance criteria. For further to above-ground storage. application or were free from conflicts discussion of comments related to the Many members of the public proposed conditions of certification, expressed a desire for EPA to oversee of interest. Many comments requested that EPA release the names and refer to the preceding preamble section entitled, ‘‘Significant Changes Made to 8 WIPP Land Withdrawal Act (‘‘WIPP LWA’’), qualifications of individual contractor Pub. L. 102–579, as amended by the 1996 WIPP employees who provided technical LWA Amendments, Pub. L. 104–201, Section 8(d). support for EPA’s certification 9 18 U.S.C. 1905 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27361 the Final Rule in Response to performance assessment modeling and concreteasphalt water stop, another 100 Comments.’’ the containment requirements of 40 CFR feet of bentonite clay, and the shaft Part 191, a discussion of EPA’s review station concrete plug. (Docket A–93–02, VIII. How Did EPA Respond to Major of the substantive comments (except for Item V–B–2, CARD 14, Section 14.A) Technical Issues Raised in Comments? those relating to shaft seals and panel Even if water were to pass through the A. Content of Compliance Certification closures) can be found in the salt column, only a small fraction of the Applications (§ 194.14) Performance Assessment section of this salt column would be removed. Due to 40 CFR Part 194 sets out those preamble. A discussion of the comments the ongoing inward creep of the Salado elements which the Agency requires to on the engineered features related to Formation, the salt column would still be in a complete compliance long term performance, specifically on be consolidated after such a dissolution application. In general, compliance the shaft seal design and panel closure episode. Finally, DOE’s PA calculations applications must include information system, are discussed below. do not include ‘‘credit’’ for bentonite relevant to demonstrating compliance a. Shaft Seals. In the CCA, DOE swelling, capture of water by clay, or the with each of the individual sections of described the seals to be used in each adsorption of water into dry halite’all 40 CFR Part 194 to determine if the of the four shafts and included the processes that would tend to reduce WIPP will comply with the Agency’s design plans and the material and water predicted to reach the salt radioactive waste disposal regulations at construction specifications for the seals. column’and the PA results are therefore 40 CFR Part 191, Subparts B and C. The (Docket A–93–02, Item II–G–1, CCA conservative. Therefore, EPA concludes Agency published the ‘‘Compliance Chapter 3.3.1, Chapter 8.1.1, and that dissolution of the salt column is not Application Guidance for the Waste Appendix SEAL) The purpose of the a concern. (Docket A–93–02, Item V–B– Isolation Pilot Plant: A Companion shaft seal system is to limit fluid flow 2, CARD 14, Section 14.E; Item V–B–3, Guide to 40 CFR Part 194’’ (‘‘CAG’’) within the shafts after the WIPP is Section F.2) which provided detailed guidance on decommissioned and to ensure that the Commenters questioned the ability of the submission of a complete shafts will not become pathways for the shaft seals to perform as expected compliance application.10 radionuclide release. The shaft seal because the material and construction of system has 13 elements that fill the shaft Any compliance application must the seals have not been tested. However, with engineered materials possessing include, at a minimum, basic EPA found that DOE performed and high density and low permeability, information about the WIPP site and referenced numerous tests and including concrete, asphalt, clay, disposal system design, and must also experiments to establish the material compacted salt, cementitious grout, and address all the provisions of the characteristics of importance to earthen fill. The compacted salt column compliance criteria; these requirements containment of waste at the WIPP. The component of the system within the are embodied in § 194.14. The characteristic of primary importance is Salado is intended to serve as the documentation required in the the material’s permeability, the degree primary longterm barrier by limiting compliance criteria is important to to which fluids can travel through the fluid transport along the shaft during enable a rigorous, thorough assessment material. The permeability of concrete, of whether the WIPP facility will the 10,000 year regulatory period. The EPA proposed that DOE’s shaft seal asphalt, and bentonite clay are well comply with the disposal regulations. documented, and DOE performed The EPA thoroughly reviewed DOE’s design is adequate because the system can be built and is expected to function numerous experiments to demonstrate compliance certification application the applicability of these characteristics (‘‘CCA’’) and additional information as intended. (Docket A–93–02, Item V– B–2, CARD 14, Section 14.E; and Item to the WIPP’s site specific conditions submitted by DOE, and proposed that (e.g., high brine concentration). The DOE complies with each of the V–B–3) Commenters expressed concern that DOE documented many laboratory and requirements of § 194.14, conditioned insitu tests of the permeability of upon DOE’s implementation of the most dissolution of the salt column could occur because the overlying Rustler compacted crushed salt including a robust panel closure system design largescale field test to demonstrate the (designated as Option D) with slight aquifer has karst features and cannot be relied upon to retard the migration of feasibility of implementing such a seal modification. The succeeding sections measure. (Docket A–93–02, Item II–G–2, address public comments related to radionuclides. (For more information on karst, refer to the preamble sections on Appendices SEAL, PCS, DEL, and § 194.14. (For more detailed MASS) discussions, see Docket A–93–02, Item Performance Assessment, Geological The technology planned for V–B–2, CARD 14; and Item V–B–3.) Scenarios.) Dissolution of salt (halite) in the WIPP shafts would require a source constructing the shaft seals has been 1. Site Characterization and Disposal of water that is not saturated with salt, tested in the real world. The System Design and a sink, i.e., some location for the construction equipment and procedures The EPA received numerous public water to flow to after it has dissolved necessary to emplace the seal materials comments on issues related to the the salt in the shafts. Since all of the are in large part the same as those used requirements of §§ 194.14(a) and ground water from the top of the Salado to excavate the WIPP, but used in 194.14.(b), primarily related to the downward is saturated with salt (i.e., it reverse. Except for salt, the shaft seal geological features, disposal system is ‘‘brine’’), the unsaturated but highly component materials are commonly design and characteristics of the WIPP. saline water would probably come used in construction. Salt has been Since the geology and disposal system down the shaft from the Rustler extensively tested to determine its characteristics are directly related to Formation. In order to reach the salt properties and behavior in the component of the shaft seal, that water conditions which will exist in the shafts 10 Section 194.11 provides that EPA’s certification would have to pass through or around after the WIPP is closed. The EPA finds evaluation would not begin until EPA notified DOE 490 feet of concrete, asphalt, and that the shaft seal design has undergone of its receipt of a ‘‘complete’’ compliance bentonite layers. Then, after flowing extensive technical review and testing application. This ensures that the full one-year period for EPA’s review, as provided by the WIPP through 550 feet of compacted salt by DOE that shows it is feasible to LWA, shall be devoted to substantive, meaningful column, the saturated water would have construct and is expected to perform as review of the application. (61 FR 5226) to flow through or around another intended. (Docket A–93–02, Item V–B– 27362 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

2, CARD 14, Section 14.E; Item V–B–3, on which compliance was based should on which certification is based, the Section F.2) be actually implemented at the site. The Agency is authorized under § 194.65 to As commenters pointed out, and EPA EPA also proposed to require DOE to initiate a rulemaking to appropriately agrees, many changes may occur in use Salado mass concrete (concrete modify the certification. The EPA has knowledge of construction materials made with Salado salt) for construction retained the proposed Condition 1, and in construction methods and of the concrete barrier component of the related to the panel closure system, equipment during the 35 years before panel closure. This substitution without change in the final rule. (See the WIPP is expected to be closed. The eliminates the potential for degradation also ‘‘Conditions’’ and ‘‘Significant DOE provided a final design for the and decomposition of fresh water Changes to the Final Rule’’ sections of shaft seals which could be constructed. concrete by infiltration of brine. The this preamble.) However, EPA recognizes the fact that EPA determined that implementation of 2. Results of Assessments, Input technology may change and expects the Option D is adequate to achieve the Parameters to Performance Assessments, shaft seal plans to be periodically long-term performance modeled in the Assurance Requirements, and Waste reviewed and revised to take full PA, since DOE shows that the use of a Acceptance Criteria advantage of new knowledge or concrete barrier component is capable of construction equipment in the future. providing resistance to inward Sections 194.14(c) through (f) require Acknowledgment of this circumstance deformation of the surrounding salt and DOE to submit the results of does not mean that the existing plans prohibiting growth of the DRZ from its assessments conducted in accordance are inadequate, or that major changes in initial state. (Docket A–93–02, Item V– with 40 CFR Part 194; a description of the design are anticipated. Periodic B–13) the input parameters associated with review of the WIPP authorization(s) to Contrary to public comments, EPA such assessments and the basis for operate is required by the various found that the panel closures can be selecting such parameters; statutes and regulations applicable to constructed using currently available documentation of measures taken to the WIPP, including EPA’s review of and widely used technology. Mixing meet the assurance requirements of 40 recertification applications every five and transportation of concrete, using CFR Part 194; and a description of the years, and the State of New Mexico’s special measures to prevent segregation waste acceptance criteria and actions review of the hazardous waste permit at of fine and coarse particles (as required taken to assure adherence to such least every ten years. Shaft seal design in the Panel Closure System criteria. The EPA proposed that DOE changes may be proposed by DOE and construction specifications), and complied with §§ 194.14(c) through (f) perhaps approved by EPA several times placement in confined spaces by based on EPA’s finding that DOE before the end of the WIPP disposal pumping, is used routinely in bridge submitted the information required. The operations phase. Significant changes in and building foundations, dams, and in EPA received numerous public the designs will be required to go water supply, subway and highway comments on the results of assessments, through public noticeandcomment tunnels. The steel forms in which the input parameters to the PA, assurance procedures before approval by EPA. concrete will be confined are somewhat requirements, and the waste acceptance (§ 194.65–66) unusual in shape, but the methods of criteria. A discussion of EPA’s b. Panel Closure System. Panel construction are fairly simple and responses to substantive comments can closures are needed primarily during standardized. The Salado mass concrete be found in the corresponding sections active disposal operations at the WIPP mix is specially formulated for use in of the preamble. Based on these and during preparations for final closure the WIPP, but it has been extensively responses, EPA finds that DOE complies of the entire facility. Relative to long- tested to determine its properties (e.g., with §§ 194.14(c) through (f). For further term performance, they can serve to strength and resistance to chloride discussion, refer to CARD 14, Sections block the flow of brine between panels. degradation) as explained in 14.C, 14.D, 14.E, 14.F (Docket A–93–02, The DOE provided four options for a ‘‘Variability in Properties of Salado Item V–B–2) and Sections H.2, I.2, J.2, panel closure system in the CCA, but Mass Concrete.’’ (Docket A–93–02, Item and K.2 of the technical support did not specify which panel closure II–G–1, Ref. No. 662) document for § 194.14 (Docket A–93–02, option would be used at WIPP. The EPA One commenter asked that EPA revise Item V–B–3). reviewed the four panel closure system its panel seal design condition so that 3. Background Radiation, Topographic options proposed by DOE and DOE may reassess the engineering of Maps, Past and Current Meteorological considered that the intended purpose of panel closures when panels are to be Conditions the panel closure system is to prevent closed in the future. The EPA proposed the existing disturbed rock zone a certification condition (Condition 1) For the CCA, DOE was required to (‘‘DRZ’’) in the panel access drifts requiring DOE to implement the panel describe the background radiation in air, (tunnels) from increasing in seal design that it designated as Option soil and water in the vicinity of the permeability after panel closure (which D in the CCA. The Option D design shall disposal system and the procedures could allow greater brine flow). The be implemented as described in the employed to determine such radiation EPA considers the panel closure system CCA, except that DOE is required to use (§ 194.14(g)), provide topographic maps design identified as ‘‘Option D’’ to be Salado mass concrete rather than fresh of the vicinity of the disposal system the most robust panel closure design. water concrete. Nothing in this (§ 194.14(h)), and describe past and (Docket A–93–02, Item II–G–1, CCA condition precludes DOE from current climatic and meteorological Chapter 3 and Appendix PCS; Item V– reassessing the engineering of the panel conditions in the vicinity of the disposal B–2, CARD 14, Section 14.E; Item V–B– seals at any time. Should DOE system and how these conditions are 3, Section F.2) The EPA based its determine at any time that expected to change over the regulatory evaluation of compliance for the improvements in materials or time frame (§ 194.14(i)). The EPA proposed rule on the Option D panel construction techniques warrant proposed that DOE complied with the seal design and proposed to establish a changes to the panel seal design, DOE requirements of §§ 194.14 (g), (h), and certification condition requiring DOE to must inform EPA. If EPA concurs, and (i). The EPA did not receive substantive implement the Option D design. The determines that such changes constitute comments on these issues, except for EPA believes that the proposed design a significant departure from the design dissolution related to climate change. A Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27363 discussion of EPA’s response to the All documents sent to EPA regarding then expressed as mathematical substantive comments on dissolution certification of the WIPP are available in relationships, which are solved with can be found in the Performance EPA Air Docket A–93–02. Additional iterative numerical models, which are Assessment, Geological Scenarios and information relevant to EPA’s then translated into computer code. Disposal System Characteristics section certification evaluation that was (§ 194.23) The results of the simulations of this preamble. The EPA finds that reviewed by the Agency (e.g., DOE data are intended to show the potential DOE complies with §§ 194.14 (g) records packages, quality assurance releases of radioactive materials from through (i). For further discussion, refer records, and calculations of actinide the disposal system to the accessible to Sections 14.K, 14.L, and 14.M of solubility for americium, plutonium, environment over the 10,000-year CARD 14 (Docket A–93–02, Item V–B– thorium and uranium) is also publicly regulatory time frame. 2) and Sections H.2, L.2, N.2 and N.4 of available. Documentation of peer review The PA process must consider both the technical support document for panel meetings conducted after receipt natural and man-made processes and § 194.14 (Docket A–93–02, Item V–B–3). of the CCA has been placed in the EPA events which have an effect on the docket. See Docket A–93–02, Item V–B– disposal system. (§§ 194.32 and 194.33) 4. Other Information Needed for 1 for further information on the location It must consider all reasonably probable Demonstration of Compliance of all documentation reviewed by EPA. release mechanisms from the disposal system and must be structured and The DOE was also required, under 5. Conclusion § 194.14(j), to provide additional conducted in a way that demonstrates information, analyses, tests, or records The EPA received numerous public an adequate understanding of the determined by the Administrator or the comments on the proposed rule physical conditions in the disposal Administrator’s authorized regarding § 194.14. EPA has thoroughly system. The PA must evaluate potential representative to be necessary for reviewed the public comments and releases from both human-initiated determining compliance with 40 CFR addressed all issues raised therein. On activities (e.g., via drilling intrusions) Part 194. After receipt of the CCA dated the basis of its evaluation of the CCA and natural processes (e.g., dissolution) October 29, 1996, EPA formally and supplementary information, and the that would occur independently of requested additional information from issues raised in public comments, EPA human activities. The DOE must justify DOE in seven letters dated December 19, finds that DOE complies with all the omissions of events and processes 1996, and February 18, March 19, April subsections of 40 CFR 194.14, with the that could occur but are not included in 17, April 25, June 6, and July 2, 1997. condition that DOE must fulfill the the final PA calculations. The results of the PA are used to (Docket A–93–02, Items II–I–1, II–I–9, requirements set forth in Condition 1 of demonstrate compliance with the II–I–17, II–I–25, II–I–27, II–I–33, and II– the final rule. For additional containment requirements in 40 CFR I–37, respectively) The information information on EPA’s evaluation of 191.13. The containment requirements requested in these letters was necessary compliance for § 194.14, see CARD 14. are expressed in terms of ‘‘normalized for EPA’s completeness determination (Docket A–93–02, Item V–B–2) releases.’’ The results of the PA are and technical review. EPA staff and B. Performance Assessment: Modeling assembled into complementary contractors also reviewed records and Containment Requirements cumulative distribution functions maintained by DOE or DOE’s (§§ 194.14, 194.23, 194.31 through (‘‘CCDFs’’) which indicate the contractors (e.g., records kept at the 194.34) probability of exceeding various levels Sandia National Laboratories Records 1. Introduction of normalized releases. (§ 194.34) Center in Albuquerque, New Mexico). As described above, 40 CFR Part 194 No additional laboratory or field tests The disposal regulations at 40 CFR contains several specific requirements were conducted by DOE at EPA’s Part 191 include requirements for for the performance assessment of specific direction; however, DOE did containment of radionuclides. The WIPP. It is often difficult to discuss one conduct and document laboratory tests containment requirements at 40 CFR of the requirements in isolation from the after October 29, 1996, in order to 191.13 specify that releases of others. For example, several public present additional data to the radionuclides to the accessible comments raised concern about the Conceptual Model Peer Review Panel. environment must be unlikely to exceed CCA’s screening of the fluid injection (Docket A–93–02, Item II–A–39) specific limits for 10,000 years after scenario from the PA and EPA’s The EPA proposed that DOE complied disposal. At the WIPP, the specific subsequent analysis. In order for EPA to with § 194.14(j) because it responded release limits are based on the amount adequately address the fluid injection adequately to EPA’s formal requests for of waste in the repository at the time of issue, the Agency must discuss multiple additional information, analyses, and disposal. (§ 194.31) Assessment of the requirements related to geology and records. The EPA did not formally likelihood that the WIPP will meet these other characteristics specific to the request additional information from release limits is conducted through the WIPP site (§ 194.14), models and DOE after publication of the proposed use of a process known as performance computer codes (§ 194.23), and the rule. However, in response to assessment (‘‘PA’’). screening process for both human- comments, EPA did verbally ask DOE The WIPP PA process culminates in a initiated releases and releases by natural and Sandia National Laboratory for series of computer simulations that processes (§§ 194.32 and 194.33). information and other assistance in attempts to describe the physical Because so many of the PA issues have calculations related to the Hartman attributes of the disposal system (site similarly overlapping requirements and scenario, drilling into fractured characteristics, waste forms and are often complex, EPA has chosen to anhydrite, and the CCDFGF code and quantities, engineered features) in a combine the discussions. Therefore, the quasi-static spreadsheet with regard to manner that captures the behaviors and following discussions are framed in air drilling. (Docket A–93–02, Items IV– interactions among its various terms of the PA issues raised in E–24, IV–E–25, IV–E–26, and IV–E–27) components. The computer simulations comments, rather than according to In addition, DOE voluntarily submitted require the use of conceptual models specific PA requirements of the information on the proposed rule that that represent physical attributes of the compliance criteria. The following was considered as comments. repository. The conceptual models are sections discuss the major PA issues 27364 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations that were raised during public hearings repository and escape to the accessible conceptual model, § 194.24(a)(3)(i). The and the public comment period. For environment: cuttings,11 cavings,12 EPA did not propose, however, to more information on performance spallings,13 direct brine release, and determine that the spallings model assessment and related issues, refer to transport of dissolved radionuclides incorporated in the CCA PA ‘‘reasonably CARDs 14, 23, 32, and 33. (Docket A– through the anhydrite interbeds (i.e., represents possible future states of the 93–02, Item V–B–2) layers of rock immediately above the repository,’’ as stated in § 194.24(a)(3)(i). repository). The first four of these The EPA proposed to accept the 2. Human Intrusion Scenarios potential release pathways involve spallings model for the purposes of a. Introduction. Section 194.32 direct releases of radiation to the earth’s demonstrating compliance with requires DOE to consider, in the PA, surface in cases where people drill a § 194.23(a)(3)(i) on the basis that it has both natural and man-made processes borehole while searching for resources. been determined to produce and events which can have an effect on The DOE’s model for computing conservative overestimates of potential the disposal system. Of all the features, releases of radiation due to spallings spallings releases. (62 FR 58807) The events, and processes (‘‘FEPs’’) that are was of particular concern to the Agency now concludes that DOE has considered for the PA calculations, the Conceptual Models Peer Review Panel met the requirements of § 194.23 in its human-intrusion scenarios related to which reviewed each of the conceptual final rule. (See Docket A–93–02, Item drilling have been shown to have the models developed for the purposes of V–B–2, CARD 23, Section 7.4.) most significant impact on the disposal the PA. (See Docket A–93–02, Item V– The public commented on four system and its ability to contain waste. B–2, CARD 23, Section 7.) The peer aspects of DOE’s spallings modeling and (§ 194.33) review panel found the spallings EPA’s evaluation of that modeling: In preparing the CCA, DOE initially conceptual model inadequate because it adequacy of DOE’s spallings modeling, identified 1,200 potential FEPs, both did not fully model all potential purpose and approach of EPA’s natural and human-initiated, for the mechanisms that may cause pressure- spallings modeling, use of DOE’s WIPP PA. These FEPs were reduced in driven solid releases to the accessible GASOUT code for modeling spallings, number in the final PA calculations. environment. (Docket A–93–02, Item II– and the need to include additional The DOE may eliminate FEPs from G–12, p. 74) The DOE presented spallings mechanisms. consideration in the PA for three additional experimental evidence and Some commenters expressed concern reasons: the results of other modeling to the peer that DOE’s conceptual model for • Regulatory—FEPs can be omitted review panel and requested that it spallings used in the PA did not based on regulatory requirements. For consider whether the spallings volumes adequately represent spallings releases, example, drilling activities that occur predicted by the original inadequate as stated initially by the Conceptual outside the Delaware Basin do not have spallings model were reasonable for use Model Peer Review Panel. However, to be considered in the PA, according to in the PA. (Docket A–93–02, Items II–G– others indicated that DOE had worked §§ 194.33(b)(3)(i) and 194.33(b)(4)(i). 22 and II–G–23) After considering this on the spallings model extensively since • Probability—FEPs can be omitted additional information, the peer review the peer review panel’s review, and that because of the low probability that the panel concluded that the spallings the spallings model demonstrated that FEP will occur. For example, DOE values in the CCA are reasonable for use the volume of releases due to spalling determined that the probability of a in the PA. The panel concluded that, would be small. meteorite landing in the vicinity of the while the spallings model does not The EPA agrees that the spallings WIPP is so low that it does not need to accurately represent the future state of conceptual model was inadequate to be considered in the PA. (§ 194.32(d)) the repository, its inaccuracies are represent possible future states of the • Consequences—FEPS can be conservative and, in fact, may repository. In response to the omitted because the consequences overestimate the actual waste volumes Conceptual Models Peer Review Panel, resulting from the FEP, even if it does that would be expected to be released by DOE did substantial additional work, occur, are so small. For example, there a spallings event. (Docket A–93–02, developed a separate mechanistically- would be no consequences on the Item II–G–22, Section 4, p. 18) based model and provided supporting repository or the containment of waste The spallings conceptual model experimental data. The peer review if an archeological excavation took place relates to the following requirements of panel concluded that the spallings on the surface in the vicinity of the § 194.23: documentation of conceptual model used in the CCA PA calculated WIPP. (§ 194.32(a)) models used in the PA (§ 194.23(a)(1)); release volumes that were reasonable The following sections discuss the consideration and documentation of and probably conservative. (Docket A– major public comments on human alternative conceptual models 93–02, Item II–G–22) On the basis of intrusion scenarios. Generally, public (§ 194.23(a)(2)); and reasonable this additional work, EPA concludes comments related to whether or not the representation of future states of the that the spallings release volumes scenario was appropriately screened by repository in conceptual models calculated by the CCA spallings model DOE and to EPA’s subsequent (§ 194.23(a)(3)(i)). The EPA proposed are acceptable. Based upon this work, evaluation of this screening. Some that DOE met the requirements of the Agency also agrees with those comments addressed whether DOE’s § 194.24(a)(1) and (a)(2), and, for all commenters who stated that spallings modeling of events was appropriate. conceptual models except the spallings would result in only a small volume of The human intrusion scenarios waste being released to the accessible discussed below are: spallings releases, 11 ‘‘Cuttings’’ refers to material, including waste, environment through spallings. air drilling, fluid injection, potash that is cut by a drill bit during drilling and is Commenters asked for clarification of carried to the surface by the drilling fluid as it is mining, and carbon dioxide injection. pumped out of the borehole. EPA’s purpose in producing its For more information on human 12 ‘‘Cavings’’ refers to material that falls from the spallings evaluation reports for the intrusion scenarios, refer to CARDs 32 walls of a borehole as a drill bit drills through. proposed rule. (Docket A–93–02, Items and 33. (Docket A–93–02, Item V–B–2) Cavings are carried to the surface by the drilling III–B–10 and III–B–11) They also b. Spallings. The DOE’s models for fluid as it is pumped out of the borehole. questioned EPA’s technical approach in 13 ‘‘Spallings’’ refers to releases of solids pushed the PA included five ways in which up and out by gas pressure in the repository during these reports, particularly the radioactive waste could leave the a drilling event. discretization (time and space intervals). Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27365

Discretization is important because if therefore, acceptable to demonstrate the stuck pipe 15 and gas erosion 16 intervals are too large, modeling may compliance with the waste containment spallings mechanisms, two additional not calculate or may incorrectly requirements of 40 CFR 191.13. (62 FR ways by which high gas pressure calculate some important events, and if 58807) This conclusion is based not on conditions in the repository could result intervals are too small, modeling will be the EPA’s spallings reports prepared for in releases of solid radioactive waste to time-consuming and inefficient. the proposed rule, which have been the accessible environment. In The EPA prepared its Spallings questioned by commenters, but on the particular, commenters asserted that Evaluation and Supplemental Spallings additional spallings analysis performed DOE had selected an incorrect value for Evaluation for the proposed rule in 17 by DOE, presented to the Conceptual the threshold waste permeability, order to model simplistically the above which the gas erosion and stuck Models Peer Review Panel, and found transport of spallings releases up a pipe mechanisms would not occur. by EPA to demonstrate that the spallings borehole during blowout. The spallings They also stated that DOE’s assumptions model used in the CCA PA did not release volumes used in the CCA PA are did not take into consideration the examine transport; rather, DOE’s conservative. (Docket A–93–02, Item III– presence of magnesium oxide (MgO) spallings model took the approach that B–2; Item V–B–2, CARD 23; and Item V– backfill, which would affect both waste all waste broken loose and able to move C–1) permeability and tensile strength. These would actually reach the earth’s surface. Some commenters expressed concern commenters suggested that EPA should The Agency used an independent model about the stability of Sandia National do further analysis, should require DOE to investigate if DOE’s spallings Laboratory’s GASOUT computer code to do more analysis, or should reject conceptual model would give that calculates spallings releases. One DOE’s spallings models and mandate conservative estimates of spallings individual had used this code to new models. Other commenters releases. The EPA believed this would calculate spallings releases due to air countered that stuck pipe and gas determine if the calculated spallings drilling, but other commenters stated erosion would not occur because of the releases were potentially acceptable for that it was not appropriate to apply the physical and mechanical properties of use in PA, despite the flaws in DOE’s GASOUT code to the air drilling the waste. model. The EPA undertook these The EPA has analyzed the validity of studies early in its own review, and in scenario. (Air drilling refers to the DOE’s decision to exclude stuck pipe the Conceptual Models Peer Review practice of using air or other substances and gas erosion mechanisms from the Panel’s review of the spallings lighter than mud as a drilling fluid.) PA. In order for these mechanisms to conceptual model, when both the Panel The EPA agrees that the GASOUT occur, there must be a combination of and the Agency were concerned about code may not be stable under some high gas pressure, low waste the results of the model. conditions. GASOUT was designed to permeability, and low waste strength. After EPA completed its own model blowout of waste during the first First, the gas pressure in the repository modeling, DOE performed additional few seconds after borehole penetration, must be sufficiently high to move waste studies using an alternative, where the driller uses mud in the to and up the borehole. Low waste mechanistic conceptual model for borehole to reduce friction during permeability is necessary to maintain spallings. (Hansen et al., Spallings drilling. The GASOUT code was only the high pressure during the drilling Release Position Paper, Docket A–93– intended to be used under specific event. Finally, low waste tensile 02, Item II–G–23) DOE’s additional strength is necessary to allow the waste conditions of waste tensile strength 14 studies showed that its original to break off and move toward the and permeability. (Docket A–93–02, spallings conceptual model always borehole. The DOE has fabricated predicted a greater volume of releases Item II–E–9) Within its range of simulated samples of waste that have than the mechanistic spallings applicability, GASOUT produces results corroded or degraded and have conceptual model that used a more that are consistent with results obtained generated gas, as is expected to occur in realistic approach to calculate spallings by other modeling approaches, such as the WIPP once waste is emplaced, and releases. As a result, both the the quasi-static model and the coupled has measured the porosity 18 of these Conceptual Models Peer Review Panel numerical model. (Docket A–93–02, samples. Waste porosity and gas and EPA concluded that released Item II–G–23) However, if GASOUT is pressure are related. This is because a volumes estimated using the original not used as designed, it may well be greater porosity means a greater volume CCA spallings conceptual model were unstable or may calculate invalid of spaces that gas can fill. By the ideal reasonable and conservative. The EPA results. In particular, EPA agrees with gas law, when the same number of gas found DOE’s analysis in the Spallings those commenters stating that it is molecules fill a larger volume, they will Release Position Paper to be more inappropriate to use GASOUT to have a lower gas pressure. The waste conclusive than the Agency’s studies in analyze the releases of spallings due to porosity also affects waste permeability, its Spallings Evaluation and air drilling. The programmer of the Supplemental Spallings Evaluation. GASOUT code himself has said that this 15 ‘‘Stuck pipe’’ means a situation where high gas pressures in the repository would break off DOE’s analysis was an improvement code was not designed to model drilling over EPA’s analysis because it was more radioactive waste and press it against a drill string using compressible fluids such as air. hard enough to stop or greatly reduce drilling. In thorough, it used much finer (Docket A–93–02, Item II–E–9) For order to continue drilling, a drill operator would discretization (smaller time and space raise and lower the drill string and, in the process, further discussion of the GASOUT code, intervals) which allowed more specific could transport waste to the surface. predictions, and it predicted both see the discussion of air drilling below 16 ‘‘Gas erosion’’ means a situation where in this preamble. radioactive waste breaks off slowly due to high gas volumes and activity of spallings pressures in the repository, enters drilling mud releases. As described in the proposed Some commenters stated that DOE surrounding the drill, and is transported to the rule, EPA examined the Spallings had erroneously excluded from the PA earth’s surface in the mud. Release Position Paper and concluded 17 ‘‘Waste permeability’’ is the degree to which that the spallings release volumes fluid can move through the waste. 18 ‘‘Porosity’’ is the fraction of space present that calculated by the spallings model used 14 Tensile strength is resistance to being pulled is open and can store gases or liquids, as opposed in the PA are conservative and, apart. to space filled by solid matter. 27366 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations since more open space in waste means comment period of 30 days. (63 FR future practices, and to model situations more space where a liquid or gas can 3863; January 27, 1998) The EPA’s study that are representative of the Delaware penetrate. Based upon DOE’s examined the frequency of air drilling Basin, rather than a wider area that is measurements of the porosity of near the WIPP, the likelihood that not representative of conditions at the surrogate waste samples, EPA found drillers would use air drilling under the WIPP site. (61 FR 5234; Docket A–92– that it is extremely unlikely that the conditions at the WIPP, and the 56, V–C–1, p. 12–12) The Agency chose required conditions of high gas pressure potential volume of radioactive waste to use current drilling practices for and low waste permeability will exist in that could be released using air drilling. resources exploited in the present and the WIPP. The high pressure necessary In the report, the Agency concluded that past as a stand-in for potential future to support gas erosion or stuck pipe air drilling is not a common practice in resource drilling practices. (61 FR 5233) mechanisms would expand the WIPP the Delaware Basin, and that air drilling The specific frequency suggested by the waste, creating a higher porosity (and through the Salado, the geologic salt commenter is arbitrary because it higher permeability). Thus, for the stratum where the WIPP is located, is applies to the entire U.S. rather than the characteristics of the WIPP waste, the not presently used in the Delaware Delaware Basin and because the permeability would not become low Basin near the WIPP. Because the use of commenter provides no reason for enough (less than 10¥16 square meters) air as a drilling fluid is not current selecting an estimated frequency of air to create a gas erosion or stuck pipe practice in the Delaware Basin, EPA drilling in 2005 rather than in some event. (Docket A–93–02, Item V–B–2, found that DOE is not required to other year. The DOE must abide by the CARD 23, Section 7.4) If the include air drilling in the PA. requirement of § 194.33(c)(1) to assume permeability is not low enough for gas (§ 194.33(c)(1)) Nevertheless, the that future drilling practices remain erosion or stuck pipe, releases may still Agency also modeled potential releases consistent with practices in the occur, but the release mechanism will of radioactive waste during air drilling, Delaware Basin at the time the CCA was be a short-lived blowout (spallings) and found that any releases would be prepared (1996). Thus, the pertinent rather than gas erosion or stuck pipe. within the range calculated in the CCA issues are whether air drilling Therefore, EPA concludes that DOE PA for mud-based drilling. constitutes current practice in the correctly modeled only the ‘‘blowout’’ The EPA received a number of Delaware Basin and, if so, how it could process in its spallings model and comments on its air drilling report. affect potential releases from the WIPP. appropriately excluded stuck pipe and Some members of the public stated that Some commenters said that air gas erosion. air drilling is a proven technology and drilling is already occurring in the c. Air Drilling. Shortly before the frequency of its use by the oil and Delaware Basin, and thus, should be publication of the proposed certification gas industry is increasing. They considered in the PA. One commenter decision, and after EPA’s cutoff date for suggested that air drilling techniques are noted that EPA should look at the addressing ANPR comments, EPA not currently being used more widely frequency of air drilling in the Texas received a comment containing a because of the limited knowledge of portion of the Delaware Basin, as well technical report stating that DOE should new developments and the industry’s as in the New Mexico portion of the have included the human intrusion resistance to changing methods. The Delaware Basin, consistent with scenario of air drilling in the PA, rather commenters implied that if these § 194.33(c)(1). Commenters also raised a than screening it out. (Docket A–93–02, obstacles are overcome, air drilling will concern that EPA’s examination of well Item IV–D–01) Normally, oil drillers occur widely in the future. One files might underestimate the will use mud in the borehole to reduce commenter recommended that the occurrence of air drilling because friction and to carry away solids that Agency require DOE to consider air information on the drilling fluid used is break free as the drill bit bores into the drilling using a frequency of 30% of all not always clear in the records. Another ground. However, in some cases, drillers wells, based upon a projected estimate commenter suggested that air drilling might instead use air, mist, foam, dust, from DOE of the use of air drilling in the could be left out of the PA only if it has aerated mud or light weight solid entire U.S. in the year 2005. In contrast, a probability of less than one chance in additives as the fluid in the borehole. other commenters stated that air drilling ten thousand, under § 194.32(d). would be less economic than mud The EPA agrees that the frequency of Public comments noted that the air drilling if the driller encountered any air drilling needs to be examined in the drilling 19 scenario was not included by interruption in the air drilling process. entire Delaware Basin. In response to DOE in the CCA, and raised the The Agency recognizes that air these public comments, EPA following issues: drilling is a proven technology for supplemented the analysis in its initial • Air drilling technology is currently extraction of oil and gas under air drilling report by conducting a successfully used in the Delaware Basin. appropriate conditions. However, EPA random sample of wells drilled in the • Air drilling is thought to be a viable believes that it is inappropriate to use New Mexico and Texas portions of the drilling technology under the speculative projections of future Delaware Basin and has determined the hydrological and geological conditions practices in the oil and gas industry frequency of air drilling in the entire at the WIPP site. • Air drilling could result in releases across the U.S. in the PA or to guess that Delaware Basin. (The initial report is of radionuclides that are substantially a practice will be used more in the located at Docket A–93–02, Item IV–A– greater than those considered by DOE in future because some drillers may 1; the supplemented report is located at currently misunderstand the Docket A–93–02, Item V–B–29.) The the CCA. In response to these concerns, EPA technology. The EPA’s compliance Agency found that air drilling is not prepared a study on air drilling and its criteria require DOE to assume that used more frequently in the Delaware likely impact on the WIPP (Docket A– future drilling practices and technology Basin as a whole than in the New 93–02, Item IV–A–1), placed it in the will remain consistent with practices in Mexico portion of the Basin. At the 95% docket, and allowed for a public the Delaware Basin at the time a statistical confidence level, EPA found compliance application is prepared. that, at most, only 1.65% of all wells in 19 In this discussion, the term ‘‘air drilling’’ refers (§ 194.33(c)(1)) The EPA included this the Delaware Basin may have been to all forms of drilling using drilling substances requirement in the compliance criteria drilled with air. In those records lighter than mud. to prevent endless speculation about examined, none of the wells were Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27367 drilled through the salt-bearing geologic site. This commenter said that drilling Although EPA concluded that there formation, as would be required to with air may even become the method was no need to include air drilling in penetrate the WIPP. This additional of choice in the WIPP area, since a the PA, the Agency conducted its own information confirms the Agency’s driller will prefer to use a technology modeling of spallings due to air drilling conclusion (as stated initially in Docket such as air drilling, which avoids loss to respond to public concerns. (Docket A–93–02, Item IV–A–1) that air drilling of circulation. Another commenter A–93–02, Item V–B–29, Section 6 and is not a current practice in the Delaware expressed concern about the Appendix A) The EPA used the quasi- Basin. conclusions of EPA’s Analysis of Air static model developed by DOE as a The EPA agrees that the well drilling Drilling at WIPP (Docket A–93–02, Item mechanistic model of spallings, an records examined in its random sample IV–A–1) that water inflow upon drilling approach that provides greater modeling may not by themselves be conclusive would prevent air drilling near the flexibility than with the GASOUT code. about whether air drilling was used at WIPP and that air drilling is not an The quasi-static model tends to specific wells. As an independent economically feasible drilling method overestimate releases of radioactive confirmation of the extent of air drilling near the WIPP. This commenter also waste because it predicts the total in the Delaware Basin (and near the stated that EPA’s estimates of the water volume of waste that is available for WIPP specifically), EPA also flow rate that can be tolerated during air transport. The total volume available for interviewed knowledgeable industry drilling were too low. transport would not all be released in contacts, many of whom were The EPA examined a report from a actuality because pressurized gas would experienced in air drilling. These commenter that found that water not be able to lift large, heavy particles individuals independently confirmed inflows from the Culebra would not up to the earth’s surface. Studies have that air drilling is rarely practiced in the prevent air drilling at the WIPP site. The shown that the quasi-static model Delaware Basin and that it is virtually report based this premise on the generally predicts larger spalled nonexistent in the vicinity of WIPP. transmissivity in some parts of the WIPP volumes than the model incorporated in (Docket A–93–02, Item V–B–29) The site. However, EPA disagrees that the the GASOUT code. (Docket A–93–02, DOE also found similar results in an transmissivity threshold mentioned in Item II–G–23, Table 3–3) For air drilling exhaustive analysis of 3,349 wells in the the report would provide sufficient conditions, EPA estimated volumes of Delaware Basin. (Docket A–93–02, IV– reason to conclude that air drilling was releases to be within the range of G–7) These independent sources of currently practical in that area. The spallings values predicted by the CCA information further verify EPA’s range of transmissivities at the WIPP and used in the PAVT evaluation. conclusion that air drilling is not a site shows that air drilling is definitely The EPA also examined the effects of current practice in the Delaware Basin. not feasible in some parts of the site, air drilling on the combined, In particular, air drilling through the and is unsuitable in other portions of complementary cumulative distribution salt section (where the waste is present) the site. The EPA also found that the functions (‘‘CCDFs’’) used to show is not consistent with current drilling possibility of excessive water inflow graphically whether the WIPP meets practices in the Delaware Basin. was only one of the reasons mentioned EPA’s containment requirements for The EPA disagrees that the frequency by industry contacts as to why air radioactive waste. (Docket A–93–02, of air drilling must be less than one in drilling was not used in the vicinity of Item V–B–29, Section 6) The EPA found ten thousand wells in order for DOE to WIPP. Other reasons, cited in EPA’s Air that the CCDFs produced by DOE were leave it out of the PA. Section Drilling Report, include sections of not significantly different from those 194.33(c)(1) requires DOE to look at unconsolidated rock above the salt produced in the PAVT. In fact, releases ‘‘drilling practices at the time a section and the potential for hitting from the WIPP were still below the compliance application is prepared.’’ brine pockets in the Castile Formation. containment requirements of § 191.13 This requirement refers to typical (Docket A–93–02, Item V–B–29) by more than an order of magnitude industry practices in the Delaware Basin Because of the reasons industry contacts when air drilling is included as a at the time a compliance application is gave for not conducting air drilling near scenario. prepared. (See 61 FR 5230; Docket A– the WIPP, the Agency disagrees that air The EPA determines that DOE does 92–56, Item V–C–1, p. 12–18; Docket A– drilling would ever become a preferred not need to include air drilling in the 93–02, Item II–B–29, p. 50.) It was not method of drilling at the WIPP site. intended to apply to experimental Commenters were concerned that PA because it is not current practice in procedures, emergency procedures, or there might be greater releases of waste the Delaware Basin. Further analyses, conjectured future practices. The with air drilling than with mud drilling. conducted by EPA solely to allay the Agency finds it unrealistic to consider a This is because air and foam are less public’s concerns on this issue, showed specific deep drilling method to be dense than mud, so it would take less that spallings releases calculated in the current practice or typical of drilling in pressure inside the repository to push CCA and the PAVT encompass the the Delaware Basin when it is used for waste toward the surface as solid waste potential impacts of air drilling (were it only a small percentage of all wells in (spallings) or as waste dissolved in brine to occur) on compliance with the the Basin. As indicated in § 194.32, (direct brine release). One individual containment requirements. deep drilling and shallow drilling are calculated spallings releases due to air See CARD 32 for further discussion of events to be considered in the PA. The drilling using DOE’s GASOUT computer the screening of features, events, and Agency believes that DOE has correctly code, and found that releases due to air processes. (Docket A–93–02, Item implemented the requirements of drilling were several orders of V–B–2) § 194.32(d) by including the general magnitude higher than the releases d. Fluid Injection Commenters stated technique of deep drilling as a scenario computed in the CCA PA. (Docket A– that DOE should not have screened out in the PA, rather than separately 93–02, Item II–D–120) Other the human intrusion scenario of fluid 20 analyzing the probability of each commenters countered that the injection from the final PA potential kind of deep drilling. GASOUT code was not designed to 20 The fluid injection discussed here refers to One commenter stated that air drilling model spallings using air drilling, and either (1) brine disposal from oil activities, (2) is a viable technique under the therefore, that the GASOUT code could maintenance of pressure in existing oil production, conditions in the vicinity of the WIPP not be applied in this situation. Continued 27368 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations calculations. Brine could be injected activities, and presence of leaking mobilize radioactive waste in the into existing boreholes, enter the boreholes. (Docket A–93–02, Item V–B– disposal system does not occur. repository, become contaminated and 22) As part of its analysis, the Agency In response to public comments, the flow to various release points. In performed additional modeling of the Agency tried to reproduce several of the § 194.32(c), EPA’s compliance criteria injection well scenario. The EPA results obtained with Bredehoeft’s specifically require DOE to analyze the concluded that, although scenarios can model using DOE’s BRAGFLO model. In effects of boreholes or leases that may be be constructed that move fluid to the two cases, EPA’s modeling produced used for fluid injection activities near repository via injection, the probability flows similar to those in the March 1997 the disposal system soon after disposal. of such an occurrence, given the Bredehoeft report. (Docket A–93–02, The fluid injection scenario has been necessary combination of natural and Item II–D–116) However, because the of particular concern to the public human-induced events, is very low. Agency’s study looked at flows in because of events that occurred in the multiple locations and Bredehoeft’s Rhodes-Yates oil field, about 40 miles Several commenters stated that either study does not specify the location of its east of WIPP but outside the Delaware EPA or DOE needed to model the predicted flows, the results are not Basin in a different geologic setting. An Hartman Scenario. One commenter directly comparable. The EPA also stated that it should be proven that oil well operator, Mr. Hartman 21 attempted to replicate Bredehoeft’s encountered a brine blowout in an oil DOE’s BRAGFLO code can reproduce modeling of high pressure conditions development well while drilling in the what is believed to have happened in that would be mostly likely to cause a Salado Formation in the Rhodes-Yates the Hartman case. Some members of the catastrophic event. However, the Field. In subsequent litigation, the court public also referred to modeling Agency found that critical aspects of found that the source of the brine flow performed by Bredehoeft and by Bredehoeft’s work are not documented was injection water from a long-term Bredehoeft and Gerstle which found sufficiently to make meaningful waterflood borehole located more than a that the Hartman scenario could cause comparisons using the BRAGFLO mile away. A fluid injection scenario releases in excess of the disposal computer code. In particular, the grid causing the movement of fluid under regulations (Docket A–93–02, Item II–D– spacing used in the model predictions high pressure is referred to as ‘‘the 116 Attachment (b)); these commenters were unclear. This information is Hartman Scenario’’ after this case. stated that neither EPA nor DOE had necessary in order to recreate The DOE initially screened out this satisfactorily modeled the Hartman Bredehoeft’s simulation. Also, EPA was activity from the PA because the Scenario. unable to determine whether the length Department’s modeling of fluid The EPA examined Bredehoeft and to which fractures grow are based on injection indicated that it would result Gerstle’s modeling of fluid injection at completely opened or partially opened in brine inflow values within the range the WIPP and finds their assumptions fractures. The Agency contacted the calculated in the CCA PA where there highly unrealistic. In particular, the primary author of the paper in order to is no human intrusion. (Docket A–93– report assumes that all brine is directly obtain additional critical information. 02, Item II–A–32) Both EPA and public injected into one anhydrite interbed in However, the author was not certain commenters on the Advance Notice of the Salado Formation. The anhydrite how they had treated these aspects of Proposed Rulemaking did not believe interbeds in the Salado are only a few modeling and had no further that DOE had performed sufficient feet thick. Therefore, a driller would documentation. (Docket A–93–02, Item analyses to rule out the potential effects need to plan specifically to deliberately IV–E–23) Because of insufficient of fluid injection related to oil inject brine into the anhydrite interbeds documentation of vital aspects of production on the disposal system. to have such a situation occur at the modeling, the Agency could not Therefore, the Agency required DOE to WIPP. Also, well operators using fluid replicate Bredehoeft’s results. In model fluid injection using more injection for oil or gas recovery would addition, due to lack of proper conservative geologic assumptions be attempting to inject brine into documentation it was not clear to EPA about the ability of Salado anhydrite to formations where petroleum and gas that Bredehoeft’s modeling represented transmit fluid. (Docket A–93–02, Item reserves are found, which are thousands the Hartman Scenario. Therefore, EPA II–I–17) This more conservative of feet below the Salado. If flooding due finds that lack of agreement between the modeling showed that fluid injection to fluid injection occurred accidentally Bredehoeft model and BRAGFLO does would have little impact on the results in the vicinity of the WIPP, the flow of not indicate that DOE’s modeling is of the PA. (Docket A–93–02, Item II–I– fluid would not be limited to the narrow inadequate. (Docket A–93–02, Item V– 36) Based on this modeling and other band of one anhydrite interbed in the B–22) information submitted by DOE on the Salado. Also, Bredehoeft and Gerstle’s Several commenters had concerns frequency of fluid injection well report assumes that fractures in the about EPA’s Fluid Injection Analysis, failures, EPA proposed that DOE’s anhydrite will extend for three or more including its conclusions that the screening was sufficient and realistic. kilometers and will remain open. This geology and the current well (62 FR 58806, 58822) Thus, EPA would require extremely high pressures construction practices near the WIPP are concluded that fluid injection could be to be generated by the brine injection extremely different from the geology screened out of the final PA calculations process. The EPA agrees that under very and well construction practices that based on low consequences to the unrealistic conditions, modeling can occurred in the Hartman case. In contrast, other commenters stated that disposal system. show fluid movement toward the WIPP The EPA performed its own under an injection scenario. However, fluid injection is unlikely to occur near WIPP and current well construction independent review of fluid injection, when using more realistic but still practices in the area will prevent which showed that the injection conservative assumptions in the injection well leakage. Some analysis must include the nature of modeling, fluid movement sufficient to anhydrites, duration of injection commented that EPA’s probability estimates for the chain of events that 21 BRAGFLO predicts gas generation rates, brine or (3) water flooding to increase oil recovery. In the and gas flow, and fracturing within the anhydrite could lead to a blowout caused by fluid Delaware Basin, the fluid would most likely be marker beds in order to calculate the future of the injection were overly optimistic and brine. repository. that the probability estimate ignores Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27369 experience with severe water flows in be screened from the PA. (Docket A–93– understates the length of fractures New Mexico. 02, Item III–B–22) After considering compared to another modeling The EPA concluded that current well geologic information, well history and technique, Linear Elastic Fracture construction practice makes it unlikely age, construction standards, and Mechanics (‘‘LEFM’’). Shorter fractures that there could be a well failure of the operating practices, the Agency would mean that contaminated brine nature of the ‘‘Hartman scenario’’ that concludes that reported water flows in does not travel as easily, which lessens occurred in the Rhodes-Yates field the Salado Formation in other areas of releases. outside the Delaware Basin. This is New Mexico are not representative of The Agency disagrees that DOE’s because regulatory requirements for conditions in the vicinity of the WIPP. modeling of anhydrite fracturing is drilling are much more rigorous near the (Docket A–93–02, Item V–B–22) Even if inadequate. The independent WIPP than was the case at the Rhodes- an injection event takes place, the Conceptual Models Peer Review Panel Yates field at the time of the Hartman predicted low consequence is sufficient found that the ‘‘type of fracture case. Also, the Agency reiterates that reason to remove it from consideration propagation and dilation used in the there are significant differences in the in the PA. conceptual model has been geology near the WIPP and in the One commenter stated that EPA substantiated by in situ tests.’’ The Rhodes-Yates field where the Hartman should require DOE to revise its PA Panel also found that the conceptual case occurred, that should not be model to include the Hartman Scenario model was adequate. (Docket A–93–02, ignored. The vertical distance between and perform another PA. In contrast, Item II–G–1, Appendix PEER.1) The the formation where brine would be another commenter stated that fluid EPA finds that the mathematical injected for disposal and the formation injection events will not impact ‘‘porosity model’’ used in the CCA PA where the repository is located is greater repository performance, even with adequately implements the conceptual than the vertical distance that fluid is conservative assumptions, so fluid model for anhydrite fracturing. This believed to have traveled in the injection can be excluded from the PA. mathematical model used a combination Hartman case. This distance, and effects The Agency finds that: • of field test data at lower pressures and of friction, would make it more difficult Commenters’ modeling of fluid the theory of continuum mechanics at for fluids to travel vertically upward at injection that predicted potential higher pressures. the WIPP than in the Hartman case. releases exceeding EPA standards was Some features of LEFM are not Interbeds near the WIPP site are more based upon unrealistic assumptions that appropriate for representing the numerous and are likely to be thinner would maximize releases. than in the Hartman case, thereby • The EPA tried to replicate scenarios anhydrite interbeds. LEFM predicts that reducing the likelihood of flow between similar to the Hartman case using DOE’s a single, long fracture hundreds of feet the repository and the WIPP boundary. BRAGFLO model. Some results were long will be created in a homogeneous The Agency concludes that the geology similar in magnitude to modeling medium. The Agency finds that this in the WIPP area will play an active role results presented by commenters, but approach is inappropriate for the in reducing fluid movement, or in an not directly comparable. anhydrite interbeds in the Salado at the extreme case, preventing a massive well • Modeling by DOE predicts that WIPP, which already contain numerous blowout. (Docket A–93–02, Item V–B– fluid injection will cause low flows that small fractures. (Docket A–93–02, Item 22) will not significantly impact the results IV–G–34, Attachment 5; Item V–C–1, While EPA accepted DOE’s argument of PA. Section 194.23) Field tests found that that the fluid injection scenario can be • Well construction procedures near fractures branched into a series of screened out of the PA on the basis of the WIPP have changed due to fractures following preexisting fractures low consequence, DOE presented regulatory requirements; therefore, it is or weaknesses near the injection hole, supplemental information that also unreasonable to assume that the same rather than producing a single, long- indicated that the probability of a well procedures from the Hartman case distance fracture. In the case of fluid catastrophic well failure would be low. will occur near the WIPP. injection, these fractures would store The EPA’s Fluid Injection Analysis for • There are significant geological fluid, which would slow down and the proposed rule also examined the differences between the WIPP site and shorten further fractures. The pre- chain of events necessary to cause the Rhodes-Yates field in the Hartman existing fractures will produce a fracture catastrophic failure for a well. The EPA case. front, such as that modeled by estimated that the probability of this For all of these reasons, EPA BRAGFLO, rather than a single fracture chain of events occurring for a given concludes that it is not necessary to radius, as modeled by an LEFM. Two well in the vicinity of the WIPP was repeat the PA using the scenario of fluid studies cited by commenters as support low’within the range of one in 56,889 to injection. (Docket A–93–02, Item V–B– for use of LEFM in fact question the one in 667 million. (Docket A–93–02, 22; Also, see Docket A–93–02, Item V– applicability of LEFM to WIPP Item III–B–22) These estimates of B–2, CARDs 23 and 32 for further anhydrites and recommend that DOE probability were intended to illustrate discussion of fluid injection.) consider alternative conceptual models. in this hypothetical failure scenario the A related issue raised by commenters (e.g., Docket A–93–02, Item IV–G–38) chain of events that must all occur for was DOE’s modeling of fractures in the The EPA concludes that BRAGFLO is an injection well to impact the WIPP. anhydrite interbeds directly above the more appropriate to use for WIPP than The commenters objected to the lowest WIPP. Such fractures could allow a pure linear elastic fracture mechanics probability estimate, but did not state injected brine to enter the repository, to model because there are pre-existing which probabilities or assumptions in dissolve waste, and to release fractures in the anhydrite layers that the chain of events that they believed radioactivity outside the WIPP. must be accounted for in the conceptual EPA had incorrectly selected. The EPA Commenters stated that DOE’s model for model. The EPA finds that the notes that this estimate of low anhydrite fracturing was inadequate to conceptual model based on a single probability was only one of many describe observed changes at the WIPP fracture is fundamentally flawed for reasons cited in the technical support and was not based on sufficient application in WIPP anhydrites. The document for EPA’s proposed experimental data. Some commenters Agency also finds that the model determination that fluid injection could stated that DOE’s model significantly incorporated in the PA is appropriate, 27370 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations and that further modeling with revised stating that the effects of solution In the CCA (Appendix SCR), DOE computer codes is not necessary. mining on the repository would be determined that CO2 injection is not a e. Potash Mining. Public comments substantially different than those from current drilling practice in the Delaware raised concerns about DOE’s estimates conventional mining and could cause Basin and therefore omitted it from of the potash reserves in the vicinity of the WIPP to exceed the containment consideration in the PA. For the the WIPP and DOE’s evaluation of the requirements. After examining these proposed rule, EPA concurred with DOE solution mining scenario. The primary comments, EPA concluded that the that CO2 injection was not a current effects that mining could have on the scenarios set forth in the comments practice. However, as a result of the repository are opening existing fractures were not realistic and that the public comments, EPA reviewed the in the geologic formations above the commenter’s conclusion was based on issue and determined that CO2 injection WIPP and increasing hydraulic an extreme example of subsidence from does occur in the Texas portion of the conductivity as a result of subsidence. solution mining. The EPA disagrees Delaware Basin. In responding to These effects could change the flow and with the comments and concludes that comments, EPA found no evidence of path of ground water through the subsidence in the vicinity of the WIPP CO2 injection practices in the New Culebra dolomite. would not vary significantly with Mexico portion of the Delaware Basin. Several commenters stated that DOE solution mining compared to (Docket A–93–02, Item V–C–1, Section underestimated the amount of potash in conventional mining. 8) All CO2 injection projects found in the vicinity of the WIPP and therefore The EPA concludes that solution New Mexico occurred outside the underestimated the impact that mining for potash is appropriately Delaware Basin. The EPA found that extracting the additional potash would omitted from the PA because it is not a CO2 injection has only limited potential have on the performance of the current practice, and therefore, is not an for use around WIPP because of site- repository. In the CCA, DOE provided activity expected to occur prior to or specific concerns related to reservoir estimates of the mineable potash soon after disposal. As added assurance, size, proximity to existing pipelines and reserves both outside and within the the Agency also finds that even if reservoir heterogeneity. However, WIPP Land Withdrawal Area. The solution mining of potash were to occur because EPA confirmed that CO2 compliance criteria require DOE to in the vicinity of the WIPP, the potential injection is practiced in the Delaware consider excavation mining of only effects of such mining are consistent Basin, EPA conducted an analysis of the those mineral resources which are with those from conventional consequences that CO2 injection could extracted in the Delaware Basin. techniques and are therefore already have on the PA calculations. (§ 194.32(b)) Therefore, potash resources accounted for in the PA. (Docket A–93– In order to investigate the potential of a type or quality that are currently not 02, Item V–C–1, Section 8) effect of CO2 injection should it occur in mineable for either technological or the future, EPA conducted some f. Carbon Dioxide Injection. Public economic reasons need not be addressed bounding calculations. (Docket A–93– comments raised concerns that carbon in DOE’s analysis. The EPA determined, 02, Item V–C–1, Section 8) Using dioxide (CO through an independent analysis, that 2) injection is a current numerous conservative assumptions, drilling practice in the Delaware Basin the CCA appropriately represents the EPA estimated the rate of CO2 flow extent of currently mined resources, in that DOE inappropriately omitted from through a hypothetical wellbore accordance with the criteria. The EPA the PA calculations. Carbon dioxide annulus into an anhydrite interbed at also determined that DOE appropriately flooding is the injection of CO2 into an the depth of the WIPP repository. For considered the impact that such oil reservoir to improve recovery. CO2 example, grout in the wellbore annulus resources and excavation mining could injection is typically used in tertiary is expected to degrade only along have on the performance of the recovery processes after the economic portions of the wellbore; however, EPA repository. (Docket A–93–02, Item V–B– limits for waterflooding have been assumed that such degradation would 2, CARD 32) reached. When CO2 is injected and occur along the entire wellbore, thus mixing occurs, the viscosity of the crude Additional comments were received providing a continuous pathway for CO2 on DOE’s screening of solution mining oil in the reservoir is reduced. The CO2 migration. Other conservative from the PA. The DOE determined that increases the bulk and relative assumptions included a long time frame permeability of the oil, and increases solution mining of potash is not for injection, constant CO2 pressures at occurring in the vicinity of the WIPP reservoir pressure so that the resulting the point of injection and at the and can be omitted from the PA based mixture flows more readily toward the intersection of the interbed with the on the regulatory requirement that only production wells. When CO2 begins to borehole, and a high permeability in the currently occurring (or near-future) appear at the producing well, it is interbed. The EPA’s calculations also practices be considered in the PA. typically recovered, cleaned of assumed that CO2 would be injected (§ 194.32(c)) The EPA agrees with DOE impurities, pressurized and re-injected. into the Delaware Mountain Group that solution mining is not a current The use of CO2 flooding for enhanced below WIPP and readily migrate to practice and can be omitted from the PA oil recovery in west Texas and southern Marker Bed 139, through which CO2 is on regulatory grounds. New Mexico began in 1972. In this area, assumed to flow toward the repository. The DOE submitted supplemental most CO2 injection activity is located on These assumptions increase the information which related to the the Central Basin Platform and on the potential effect of the gas injection and potential effects of solution mining for Northwest Shelf. A limited number of therefore increase the predicted potash. (Docket A–93–02, Item II–I–31) CO2 flooding projects have occurred in radionuclide releases that are calculated The DOE concluded that the impacts of the Texas portion of the Delaware Basin. for the performance of the WIPP solution mining for potash would be the Economy of scale, oil prices, proximity repository. same as those for room and pillar to CO2 supply and reservoir These simple but conservative mining, and that the potential heterogeneity are several of the calculations for a hypothetical CO2 subsidence-induced hydraulic effects in controlling factors that strongly flood indicate that, even if it were to the Culebra would be similar to those influence whether this technique is occur, CO2 injection does not pose a for typical mining practices. Some applied at a given well. (Docket A–93– threat to WIPP. For the very comments disputed this conclusion, 02, Item V–C–1, Section 8) conservative assumptions specified in Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27371 this study, even for long periods of time, Basin over the 100-year period pockets, anhydrite interbeds, and there is little potential for injected CO2 immediately prior to the time that the potential pathways for transport of to ever reach the repository. In compliance application is prepared. waste. The EPA also required DOE to summary, DOE determined that CO2 (§ 194.33(b)(3)) Although the drilling project how geophysical, hydrogeologic injection was not a current drilling rate dictated by EPA’s requirements may and geochemical conditions of the practice in the Delaware Basin and be lower than the current drilling rate, disposal system would change due to therefore screened it from the PA based the use of a 100-year drilling rate more the presence of waste. Geology also on regulatory requirements. Based on adequately reflects the actual drilling relates to criteria at §§ 194.32 and public comments, EPA identified that may be expected to take place over 194.23, which require DOE to model limited CO2 injection activities in the the long term. (See Response to processes which may affect the disposal Delaware Basin. The EPA conducted an Comments for 40 CFR Part 194, Docket system, and to use models that analysis of the effects of CO2 injection A–92–56, Item V–C–1, p. 12–11.) The reasonably represent possible future on the repository and found that CO2 future rate of deep drilling in the PA states of the disposal system. injection can be omitted from the PA was set equal to the average rate at The EPA examined the CCA and the because of the minimal consequences which that type of drilling has occurred supplemental information provided by that would occur as a result of CO2 in the Delaware Basin during the 100- DOE and proposed to find that it injection. year period immediately prior to the contained an adequate description of g. Other Drilling Issues. A few public time that the compliance application the WIPP geology, geophysics, comments raised concerns about other was prepared. Commenters did not hydrogeology, hydrology and human intrusion related scenarios. For suggest that DOE had failed to include geochemistry of the WIPP disposal example, some comments disagreed known drilling events or had calculated system and its vicinity, and how these with the drilling rates that were set forth the rate inconsistently with EPA’s conditions change over time. (62 FR in the CCA. Other comments contended requirements. Therefore, EPA finds that 58798–58800) Several commenters that natural gas storage exists in the the approach taken by DOE meets the suggested that the WIPP site geology Delaware Basin and should be regulatory requirements set forth in and disposal system characteristics have considered in the PA. § 194.33(b). (Docket A–93–02, Item V– been incorrectly assessed or Several public comments stated that B–2, CARD 33) inaccurately modeled. Commenters the CCA did not provide drilling rates Natural gas storage facilities, in expressed concern with the WIPP site that are consistent with the extensive underground cavities, are known to regarding Rustler recharge; dissolution, drilling throughout the area. The EPA exist in the Salado Formation outside including karst; presence of brine in the required DOE to include the effects of the Delaware Basin. However, neither Salado; use of two dimensional drilling into a WIPP waste panel in the EPA nor DOE is aware of any natural gas modeling with the BRAGFLO computer PA. The DOE was required to separately storage in the Salado Formation of the code instead of modeling the disposal examine the rate of shallow and deep Delaware Basin. Because there is no system using a three-dimensional drilling. Shallow drilling is defined in known gas storage in the Delaware representation (2D/3D BRAGFLO), § 194.2 as drilling events that do not Basin, DOE is permitted to omit it from earthquakes, and the gas generation reach a depth of 2,150 feet below the the PA according to the requirements of conceptual model. The EPA’s response surface and therefore do not reach the § 194.32(c). to these comments is discussed below. depth of the WIPP repository. Deep In addition to determining that there b. WIPP Geology Overview. The WIPP drilling is defined in § 194.2 as drilling is no known gas storage in the Delaware is located in the Delaware Basin of New events that reach or exceed the depth of Basin, EPA conducted an analysis of the Mexico and Texas and is approximately 2,150 feet and therefore reach or exceed effects that this activity would have on 26 miles southeast of Carlsbad, New the depth of the repository. Both types the repository. The EPA’s analysis, Mexico. This area of New Mexico is of drilling events include exploratory presented in the response to comments, currently arid, but potential future and developmental wells. (See Docket shows that natural gas storage would precipitation increases were accounted A–93–02, Item V–B–2, CARD 33 for not affect the ability of the WIPP for in the PA. The Delaware Basin further discussion of drilling rates.) repository to successfully isolate waste contains thick sedimentary deposits The EPA accepted DOE’s finding that because the migration potential of the (over 15,000 feet, or 4572 meters, thick) shallow drilling would not be of gas would be minimal. that overlay metamorphic and igneous consequence to repository performance rock (1.1 to 1.5 billion years old). The 3. Geological Scenarios and Disposal and was therefore not included in the WIPP repository is a mine constructed System Characteristics PA. (Docket A–93–02, Item V–B–2, approximately 2,150 feet (655 meters) CARD 32, Section 32.G) The future rate a. Introduction. 40 CFR 194.14(a) below ground surface in the Permian of deep drilling was considered in requires DOE to describe the natural and age (6200–250 million years old) Salado DOE’s PA. The deep drilling rate set engineered features that may affect the Formation, which is composed forth in the CCA for the Delaware Basin performance of the disposal system. primarily of salt (halite). is 46.775 boreholes per square kilometer Among the features specifically required The DOE considered the primary per 10,000 years. to be described are potential pathways geologic units of concern to be (from Several commenters suggested that for transport of waste to the accessible below the repository to the surface): (1) DOE should use other, higher deep environment. This information is the Castile Formation (‘‘Castile’’), drilling rates in the PA. Comments crucial to the conceptual models and consisting of anhydrite and halite with stated that these higher rates, based on computer modeling that is done to pressurized brine pockets found locally drilling over limited areas near the determine compliance with the throughout the vicinity of the WIPP site; WIPP or on time periods shorter than containment requirements and the (2) the Salado Formation (‘‘Salado’’), 100 years (such as the last year or the individual and ground-water protection consisting primarily of halite with some last 50 years), would be more consistent requirements. In addition to a general anhydrite interbeds and accessory with current drilling rates. The EPA’s understanding of the site, EPA required minerals and approximately 2,000 feet criteria require that the deep drilling specific information on hydrologic (600 meters) thick; (3) the Rustler rate be based on drilling in the Delaware characteristics with emphasis on brine Formation (‘‘Rustler’’), containing salt, 27372 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations anhydrite, clastics, and carbonates units around it, but that it takes up to A–93–02, Item V–B–2, CARD 14, (primarily dolomite), with the Culebra thousands of years for the Culebra to Sections 14.B.4 and 14.B.5; CARD 23, dolomite member of the Rustler as the respond to changes in the environment. Section 2.4; and CARD 32, Section unit of most interest; and (4) the Dewey DOE’s modeling indicates that the 32.F.4 for detailed discussions of Lake Red Beds Formation (‘‘Dewey Culebra ground water is still responding hydrogeology.) Lake’’), consisting of sandstone, to changes in precipitation from the Commenters also stated that DOE’s siltstone and silty claystone. The latest ice age. DOE’s explanation for the estimate of the age of ground water is geologic formations below these were ground water flow in the units above the based on an unreliable methodology and included in the screening of features, Salado is embodied in the ground water that the stable isotopic compositions of events, and processes, but were not basin model which was introduced in most samples of ground water from the included in the PA calculations because Chapter 2 of the CCA. The EPA did not Rustler Formation were found to be they did not affect the performance of consider treatment of this issue in the similar to the composition of other, the disposal system. See CARD 32, CCA to be adequate and requested verifiably young, ground water in the Sections 32.A and 32.F, for a detailed additional information. (Docket A–93– area. The age of the ground water is discussion of screening of features, 02, Item II–I–17) The DOE provided important because the ground water events, and processes. (Docket A–93–02, additional information in response to basin model is based on the assumption Item V–B–2) this request. (Docket A–93–02, Item II– that the Rustler water is ‘‘fossil’’ water, c. Rustler Recharge. Numerous I–31) having been recharged under climatic comments on the proposed rule were The ground water basin model, which conditions significantly different from related to whether the Rustler simulates recharge passing slowly the present. Because the isotopic data Formation, primarily the Culebra through the overlying strata before can be interpreted differently, EPA dolomite member, would be recharged; reaching the portion of the Culebra examined the entire spectrum of data that is, whether water will infiltrate within the boundaries of the WIPP site that could be used to assess infiltration through the soil and underlying rock recognizes the possibility of localized rates, including DOE’s ground water and into the Culebra. Commenters infiltration. (Docket A–93–02, Item V– basin model, Carbon-14 data, and linked high infiltration to the potential B–2, CARD 23) The DOE included tritium data. Based on these data, EPA dissolution of the Culebra and other ground water recharge in its ground concluded that the ground water basin members of the Rustler, concluding that water basin modeling for the Culebra model provides a plausible description karst has been formed and contributes to Member of the Rustler formation. The of ground water conditions in the ground water flow. Commenters DOE also acknowledged the water- Culebra. The EPA also points out that claimed that the presence of karst bearing capabilities of the Dewey Lake recent Carbon-14 data indicate that a features would render DOE’s ground and considered this possibility in the minimum age of 13,000 years is water flow models invalid. Site PA evaluations. The DOE assumed that appropriate for Culebra waters. Further, characterization data and DOE’s ground the water table would rise in response different geochemical zones in the WIPP water modeling indicate that infiltration to increased recharge caused by up to are explained by differences in regional is very low and limited, if any, twice the current site precipitation. recharge and long residence time. dissolution is ongoing, contrary to Essentially, DOE’s conceptual model (Docket A–93–02, Item II–I–31) The EPA commenters statements. of flow in the Culebra assumes that the examined all data pertaining to ground The DOE indicated that the units Culebra is a confined aquifer in which water flow in the Rustler, and believes above the Salado (i.e., the Rustler, the the flow slowly changes directions over the DOE’s total conceptualization Dewey Lake and the Santa Rosa) are time, depending on climatic conditions. adequately described system behavior classified as a single hydrostratigraphic The ground water basin model also for the purposes of the PA. unit (i.e., equivalent to a geologic unit accounts for the current ground water d. Dissolution. In the CCA, DOE but for ground water flow) for chemistry. Current geochemical indicated that the major geologic conceptual and computer modeling. The conditions are the result of past climatic process in the vicinity of the WIPP is Rustler is of particular importance for regimes and ground water responses to dissolution. The DOE proposed that WIPP because it contains the most those changes; because the ground water three principal dissolution mechanisms transmissive units above the repository chemistry is still adjusting to the current may occur in the Delaware Basin: (i.e., has the highest potential rate of conditions, it does not reflect the lateral, deep and shallow. (Docket A– ground water flow). In particular, the current ground water flow direction in 93–02, Item V–B–2, CARD 14, section Culebra dolomite member of the Rustler the Culebra. This new interpretation 14.B.4) Deep dissolution refers to that at Formation is considered to be the allows for limited but very slow vertical the base of or within the salt section primary ground water pathway for infiltration to the Culebra through along the Bell Canyon Castile radionuclides because it has the fastest overlying beds, although the primary Formation; lateral dissolution occurs ground water flow in the Rustler source of ground water will be lateral within the geological units above the Formation. The Culebra dolomite is flow from the north of the site. The EPA Salado (progressing eastward from Nash conceptualized as a confined aquifer in reviewed DOE’s conceptualization of Draw); and shallow dissolution, which the water flowing in the Culebra ground water flow and recharge, and including the development of karst and is distinct from rock units above or believes that it provides a realistic dissolution of fracture fill in Salado below it and interacts very slowly with representation of site conditions marker beds and the Rustler, would other rock units. In general, fluid flow because it plausibly accounts for the occur from surface-down infiltration of in the Rustler is characterized by DOE inconsistencies in the current ground undersaturated water. Lateral, strata- as exhibiting very slow vertical leakage water flow directions and the bound dissolution can occur without through confining layers and faster geochemistry. The EPA examined this shallow dissolution from above. lateral flow in conductive units. (Docket treatment of recharge in the PA To the west, the slight dip in the beds A–93–02, Item V–B–2, CARD 14, modeling and determined it to be an has exposed the Salado to near-surface Sections 14.B.4 and 14.B.5) The DOE appropriate approach that reasonably dissolution processes; however, DOE stated that the Culebra member bounds and accounts for the impact of estimated that the dissolution front will conceptually acts as a ‘‘drain’’ for the potential future recharge. (See Docket not reach the WIPP site for hundreds of Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27373 thousands of years. Near-surface fractures using a dual porosity model, the disposal system itself. The EPA dissolution of evaporitic rocks (e.g., and has accounted for permeability examined hydrogeologic data (e.g., gypsum) has created karst topography variability by developing transmissivity transmissivity and tracer tests) from west of the WIPP site, but DOE fields based upon measured field data DOE’s wells at and near the WIPP site contended that karst processes do not which reflect the varying transmissivity and found no evidence of cavernous appear to have affected the rocks within values. This dual porosity conceptual ground water flow typical of karst the WIPP site itself. The DOE indicated model recognizes that fluid may flow terrain at the WIPP site. Similarly, a that while deep dissolution has through both the rock matrix and field investigation conducted by EPA occurred in the Delaware Basin, the fractures at the site. The use of dual during the summer of 1990 to assess the process of deep dissolution would not porosity assumes ground water flows occurrence of karst features showed no occur at such a rate near the WIPP that through fractures, but allows solutes to evidence of significant karst features, it would impact the waste containment diffuse into the matrix. The EPA such as large channels, dolines, capabilities of the WIPP during the concludes that while fractures are sinkholes, or collapsed breccias (other regulatory time period. The DOE present in Rustler Formation units and than those at, for example, at WIPP–33 concluded that the potential for slow vertical infiltration does occur, and Nash Draw) in the immediate WIPP significant fluid migration to occur there is no evidence that indicates vicinity. (55 FR 47714) Available data through most of these pathways is low. fractures are conduits for immediate suggest that dissolution-related features However, DOE also concluded that fluid dissolution of Rustler or Salado salts, or occur in the immediate WIPP area (e.g., migration could occur within the that pervasive infiltration and WIPP–33 west of the WIPP site), but Rustler and Salado anhydrite marker subsequent dissolution of the Salado these features are not pervasive and are beds and included this possibility in PA Formation or Rustler is a rapid, ongoing not associated with any identified calculations. In the proposed rule, EPA occurrence at the WIPP site. Further, preferential ground water flow paths or concluded that deep, lateral, and ground water quality differences anomalies at the WIPP site. (Docket A– shallow dissolution (including karst between the more permeable units of 93–02, Item V–B–2, CARD 14, Section features and breccia pipes) will not the Rustler Formation support relative 14.B.5) Therefore, the groundwater serve as significant potential hydrologic isolation (i.e., the water in modeling in the PA is adequate. radionuclide pathways and that the the Magenta member interacts very little Several commenters stated that poor potential for significant fracture-fill with the water in the Culebra member), Rustler Formation core recovery at dissolution during the regulatory time or at least they support very slow WIPP indicates the presence of karst. period is low. (Docket A–93–02, Item V– vertical infiltration that has not allowed The commenters state that fragmented B–2, CARD 14, Section 14.B.5; Item V– for extensive geochemical mixing of core samples containing dissolution B–3, Section B.3.t) ground waters in these units. residues are a clear indication of Comments on the proposed rule Many commenters suggested that unconsolidated or cavernous zones stated that shallow dissolution and karst WIPP cannot contain radionuclides capable of transmitting water with little features occur at WIPP and will affect its because WIPP is in a region of karst resistance. However, core recovery is containment capabilities. The EPA does (topography created by the dissolution related to rock strength, and does not not agree with DOE’s assertion that the of rock). Karst terrain typically exhibits necessarily have an association with distribution of salt in the Rustler is cavernous flow, blind streams, and local hydrologic conditions. In the case solely a depositional feature because potential for channel development that of WIPP, cores that were attempted Rustler transmissivity (which is related would enhance fluid and contaminant through fractured material, including to fracture occurrence in the Rustler) migration. Numerous geologic the Culebra, exhibited poor recoveries. corresponds somewhat to the investigations have been conducted in The EPA agrees that fractured Rustler is occurrence of salt in the Rustler. This the vicinity and across the WIPP site to ′present at test well H–3. However, EPA implies that some post-Rustler assess the occurrence of dissolution does not believe that the presence of dissolution has occurred which impacts (karst) and the presence of dissolution- fractured material in the Rustler the fracturing in Rustler rocks. However, related features. The EPA reviewed indicates that karst processes are active. the evidence observed by EPA indicate information and comments submitted In fact, the development of fractures can many Rustler features were formed by DOE, stakeholders, and other occur for various reasons unrelated to millions of years ago (e.g., the breccia members of the public regarding the dissolution (e.g., removal of overlying zone in the exhaust shaft, or at WIPP– occurrence and development of karst at rock due to erosion). The DOE 18, where anhydrite/clay-rich strata may the WIPP. (Docket A–93–02, Item V–B– recognized the presence of fractures be halite dissolution residues). Other 2, CARD 14, section 14.B.5) The EPA within the Culebra, and included this Rustler features (e.g., salt distribution in acknowledges that karst terrain is dual porosity system in the PA the Rustler) could have occurred present in the vicinity of the WIPP site modeling. In addition, core loss is a sometime after the Rustler was boundary near the surface. Near-surface common occurrence in the drilling of all deposited, but there is no evidence to dissolution of evaporitic rocks (e.g., kinds of rocks, sometimes associated indicate that ongoing dissolution of gypsum) have created karst topography with fracture and other causes related to soluble material in the Rustler or at the west of the WIPP site. Nash Draw, drilling technology, as well as the Rustler-Salado contact will modify the which (at its closest to WIPP) is occurrence of soft or incompetent rock. existing transmissivity to the extent that approximately one mile west of the The EPA concludes that to interpret all the results of PA will be affected. WIPP site, is attributed to shallow zones of lost core as zones of karst is (Docket A–93–02, Item V–B–2, CARD dissolution and contains karst features. inappropriate, as other rock features 14, Section 14.B.5) (Docket A–93–02, Item V–B–3, Section contribute to core loss which have The EPA concurs that the presence of B.3.t) The EPA also recognizes the nothing to do with cavernous porosity. fractures and related fracture fill that potential importance of karst The EPA reviewed information could be attributed to dissolution or development on fluid migration. pertinent to the potential development precipitation could significantly impact The EPA agrees that karst features of karst in the WIPP area and believes ground water transport in the Rustler. occur in the WIPP area but concluded that the near continuous presence of the The DOE modeled the presence of that karst features are not pervasive over more than half-million year old 27374 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

Mescalero Caliche over the WIPP site is microbial respiration. If there is no situation. The Department’s gas a critical indicator that recharge from inflow of brine into the repository, generation conceptual model the ground surface to the bedrock neither corrosion of iron drums nor incorporates the following basic hydrologic regime has not been survival of microbes would occur, so gas premises: sufficient to dissolve the caliche at the generation would not occur. Therefore, • Gas is generated primarily by metal site. If active dissolution of the although the commenters correctly corrosion and microbial processes; evaporites in the subsurface were noted that initial WIPP studies did • Gas generation is closely linked to occurring in the WIPP area, it would be assume the salt to be ‘‘dry,’’ the other processes; expected that collapse features would be presence of interstitial brine has long • Gas generation from microbial evident in the Mescalero above the area been recognized and is accounted for in processes will not always occur; • where the dissolution is, or has the PA. (Docket A–93–02, Item V–B–2, High gas pressures in the repository occurred. As noted above, EPA has CARD 14, Section 14.E.5; Item V–B–3, can cause the Salado anhydrite interbeds to fracture; and found no evidence of direct Section F.2) • precipitation-related flow increases In the CCA discussion of the gas High gas pressure is necessary typical of karst terrain, and no field generation conceptual model, DOE before spalling and direct brine releases evidence of large channels or other karst indicates that brine is expected to be can begin. features. The relative pervasiveness of present in the repository due to a The DOE performed experiments on the Mescalero Caliche over a long natural inflow of brine. Corrosion of the gas generation rates for the 1992 PA and period of time is also an indication that waste containers, generation of gases updated these experiments more there has been an arid climate and very resulting from waste corrosion and recently. (Telander, M.R. and R.E. low recharge conditions over a long microbial degradation, and the effects of Westerman, 1997. ‘‘Hydrogen period of time at the WIPP site. This, these processes on the disposal system Generation by Metal Corrosion in combined with DOE’s near-future components have been addressed in the Simulated Waste Isolation Pilot Plant precipitation assumptions, led EPA to DOE PA and the EPA-mandated PAVT. Environments,’’ SAND96–2538; see conclude that karst feature development (Docket A–93–02, Item V–B–2, CARD Docket A–93–02, Item V–B–1.) The gas will neither be pervasive nor impact the 14, Section 14.D; Item V–B–2, CARD 23, generation rates are important in The containment capabilities of the WIPP Section 2.4; Item V–B–3, Section E.2) PA because build-up of high gas during the 10,000 year regulatory The DOE also considered that additional pressures increases the chance for period. (Docket A–93–02, Item V–B–2, brine could be introduced to the waste releases if a drill bores into the CARD 14, Section 14.B.5; Item V–B–3, area if a drilling event passed through repository. Section 3.B.t) the waste and subsequently hit a brine During the public comment period, The EPA concludes that dissolution pocket. The presence of a pressurized commenters questioned the gas has occurred in the WIPP area outside brine pocket beneath WIPP was generation rates used in the gas of the WIPP site, as evidenced by karst addressed in the PA under the Human generation conceptual model. One features like Nash Draw. It is possible Intrusion Scenarios whereby the commenter stated that calculated that dissolution has occurred at the reservoir is penetrated by a borehole corrosion rates were too low because WIPP site sometime in the distant past and brine is subsequently released into they are based upon long-term tests that (i.e., millions of years ago for strata- and mixed with the waste and show lower rates than short-term tests, bound features) associated with a eventually discharged either into the they assume a high pH, and they geologic setting other than that currently Culebra or at the ground surface. The include a minimum rate of zero, present at WIPP; however dissolution in EPA concludes that DOE adequately perhaps by assuming that salt the Culebra is not an ongoing process at considered the presence of brine in PA crystallization will prevent corrosion. the WIPP site. Thus EPA finds that modeling because it included the The commenter also stated that DOE’s modeling (which assumes no possibility of encountering a brine corrosion rates used in the model karst within the WIPP site boundary) is pocket in its intrusion scenarios, and should account for the fact that direct consistent with existing borehole data because the potential effects of brine on contact with salt and backfill increases and other geologic information. corrosion rates and gas generation were the rate. The commenter further stated e. Presence of Brine in the Salado. incorporated in PA models. For more that DOE seemed to use the observed Numerous commenters stated the information on brine pocket parameter data to set the upper limit of a Salado Formation will be wet and that values, see the subsequent discussion of distribution of corrosion rates, rather brine is weeping into the repository at Parameter Values in the Performance than the midpoint of such a a slow but significant rate, leading to a Assessment sections of this preamble. distribution, which would wet repository which will corrode the f. Gas Generation Model. Some systematically understate the corrosion waste containers. This, the commenters chemical reactions could occur in the rate because most values would be less stated, would invalidate the basic WIPP because metal containers holding than the values taken from DOE’s premises of the WIPP that dry salt beds waste may corrode and waste made observed data. Finally, the commenter would creep and encapsulate the waste from organic materials such as rubber stated that aluminum corrosion is as canisters. may decompose if water is available and significant as corrosion of steel, and that The EPA agrees that brine will enter if other conditions are conducive to it is likely to take place in the repository the repository from the Salado such decomposition. The corrosion because CO2 and iron will be present Formation via anhydrite marker beds. reaction would create hydrogen gas and will enhance aluminum corrosion. The EPA also notes that the presence of (H2). The decomposition of organic The EPA examined DOE’s studies on brine within the Salado is a key element waste would create carbon dioxide (2) gas generation rates. The EPA disagrees of the PA modeling; brine inflow is and methane (CH4). These gases would that the assumptions of long-term rates, assumed to occur and the impact of build up in the repository after it is pH, and minimum corrosion rate are not brine inflow on gas generation is sealed, increasing pressure inside the well-founded. Since the results of the assessed. Brine is necessary for both of waste rooms. corrosion testing are used to develop a the processes that may cause gas The DOE developed a gas generation long-term hydrogen gas generation rate generation: either drum corrosion or conceptual model to describe this for the repository that applies over Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27375 hundreds of years, it is appropriate that selected by DOE did not fully reflect dimensional modeling of brine and gas DOE developed the rate based on other uncertainties. These uncertainties flow.) The results of DOE’s modeling hydrogen generation over a longer time included the accelerated corrosion of show that iron is consistently left over (12 to 24 months) rather than for a steel in reactions with other materials after reacting with all available brine. shorter time. Data indicate that during such as backfill and aluminum. Data (Docket A–93–02, Item II–G–7, Fig. the first few months of the test, the from DOE tests indicated that corrosion 2.2.9) Based upon data on these corrosion reaction had not yet stabilized rates might be twice as high as those reactions, the Agency concludes that at equilibrium, producing more used in the PA. (Docket A–93–02, Item enhanced corrosion of aluminum due to hydrogen gas than would have been V–B–14) Thus, in the PAVT, EPA CO2 and iron will not increase releases expected at equilibrium for the amount required DOE to double the maximum of radioactivity because brine will not of iron present. (Docket A–93–02, Item corrosion rate to assure that these other be left over to go to the surface as direct II–G–1, CCA Reference #622) Therefore, uncertainties were more fully reflected. brine releases. (Docket A–93–02, Item the higher rate of gas generation (Docket A–93–02, Item II–G–28) V–C–1) observed in the short-term is unlikely to (Doubling the corrosion rate would be g. Two-Dimensional Modeling of Brine represent what happens in the expected to cause the gas generation rate and Gas Flow. The DOE modeled the repository over hundreds of years. to rise but not necessarily double, since flow of brine and gases within the The DOE’s assumption of high pH other factors such as microbial repository in the BRAGFLO computer (about 10) is consistent with data on the degradation also influence gas code. The DOE simplified this model by use of magnesium oxide (MgO) backfill. generation.) This and other changes representing the repository as a space in Because DOE has committed to using made in the PAVT showed that the two dimensions rather than in three MgO backfill in the repository in the repository remained in compliance with dimensions, as it is in reality. The CCA, EPA finds it reasonable to assume the standards. Department made this simplification in this pH in the repository. (See the The commenter correctly notes that order to speed up computer calculations preamble section ‘‘Engineered Barriers’’ the corrosion data from DOE’s studies significantly. The DOE performed a for further discussion of MgO backfill.) were used to set the upper limit of a screening analysis titled S1: Verification Furthermore, even if the MgO were not uniform distribution of corrosion, rather of 2D-Radial Flaring Using 3D Geometry fully effective and the pH were to drop than a mid-point. (Telander, M.R. and to see if the two-dimensional BRAGFLO from near 10 to between 7 and 8, the R.E. Westerman, 1997. See Docket A– model would predict similar results to enhanced corrosion rate expected at that 93–02, Item V–B–1.) However, EPA does a three-dimensional model. (WPO lower pH is already reflected in the not agree that this practice would #30840) In Appendix MASS, probability distribution for the corrosion systematically understate the corrosion Attachment 4–1 of the CCA, DOE rate parameter. DOE’s experimental data rate under the conditions expected to explained that the results of the show that MgO backfill will function as occur in the repository. The screening analysis showed that a three- assumed in the CCA. Therefore, EPA experimental rate was obtained under dimensional model would not give concludes that DOE considered the pH conditions substantially lower than significantly different results from the issue of pH and realistically those expected in the repository (i.e., 7.4 two-dimensional model used in the PA. incorporated it into the model. to 8.4 versus 9.2 to 9.9). The corrosion The EPA examined DOE’s The DOE took its minimum corrosion rate is expected to be at least an order documentation to determine if the CCA rate of zero from studies on steel of magnitude lower at the higher pH complied with EPA’s requirements for corrosion rates when the steel is in a than at the pH expected in the documentation of conceptual models humid environment and also when steel repository in the presence of MgO. and consideration of alternative is submerged in brine. The DOE found (Docket A–93–02, Item V–B–14) conceptual models under §§ 194.23(a)(1) that virtually no corrosion occurred and Therefore, the higher corrosion values and (a)(2). The EPA reviewed the no hydrogen gas was generated under (i.e., those based on the study) represent screening analysis and concluded in the humid conditions. Also, the studies extreme conditions, rather than those proposal that DOE sufficiently show that the steel has an extremely low expected in the repository, and the documented its rationale and approach corrosion rate when it is submerged in parameter range would account for all behind using a two-dimensional model brine at the higher pH expected in the values that are likely to occur. In for brine and gas flow in the repository. WIPP. Some DOE studies also found addition, as noted above, EPA required (62 FR 58808) that salt films may prevent corrosion, as that the maximum corrosion rate be One commenter stated that DOE’s the commenter mentioned. (Docket A– doubled in the PAVT to account for screening analysis suggested that the 93–02, Item II–G–1, CCA Appendix uncertainties in this parameter. The two-dimensional (‘‘2D’’) BRAGFLO MASS, Attachment MASS 8–2) Based Agency believes that this addresses the model might underestimate releases of on all these studies, EPA concludes that concerns raised by the commenter. radionuclides to the surface under DOE’s minimum corrosion rate is The commenter notes that CO2 and higher gas pressures. The commenter supported and appropriate. iron will enhance the corrosion of stated that several three-dimensional The DOE assumed that the corrosion aluminum. Although EPA agrees this is (‘‘3D’’) BRAGFLO simulations of the rates of steel submerged in brine were true, the Agency believes it does not repository should be performed using uniformly distributed from zero to 0.5 affect the results of the PA. Carbon parameter values from the CCA PA. The micrometers per year. The EPA believes dioxide reacts with MgO, so CO2 will recommended analysis would include that the bases for the parameter not be available to reduce the brine pH calculations of direct brine releases assumptions are adequately and to enhance corrosion. Second, (releases of brine contaminated with documented and the use of the accelerated corrosion of aluminum is radioactive waste) and spallings particular parameter distribution is not a significant factor in the WIPP’s (releases of solid waste pushed out of consistent with demonstrating the performance, since brine will be the repository under high pressure), and concept of reasonable expectation for consumed in corrosion reactions and an assessment of how much brine the H2 gas generation rates used in the will lead to smaller direct brine releases. would be consumed by chemical CCA. However, EPA was concerned that (This is also discussed in the following reactions. Another commenter stated the maximum corrosion rate value preamble section concerning two that the screening analysis had been 27376 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations misinterpreted because details of the In addition, EPA found that DOE repository will persist as an assumptions used in the original sufficiently documented its underground opening. The EPA notes screening analysis had not been development of conceptual models and that the site of the January 4, 1998, considered. This commenter also stated scenarios, including alternative earthquake is located in the Rio Grande that results of additional analysis conceptual models considered, in the Rift—over 100 miles east of WIPP—and submitted by DOE as comments showed CCA and additional documentation seismic activity in that area, including that the two-dimensional BRAGFLO submitted to the Agency. Therefore, the January 4, 1998 earthquake, was too code used in the CCA PA results in a EPA finds DOE in compliance with the small to have an impact at WIPP. conservative estimate of the releases requirements of §§ 194.23(a)(1) and Therefore, EPA finds that the effects of when compared to results from a three- (a)(2) with respect to modeling of brine earthquakes need not be considered in dimensional code. and gas flow. performance assessments. (See Docket The EPA examined the screening h. Earthquakes. Several public A–93–02, Item V–B–2, CARD 32, analysis mentioned by the commenters. comments raised concerns about the Section G) The Agency found that the divergence effect that earthquakes could have on i. Conclusion. The EPA finds that between the results of the two- the repository and the containment of DOE adequately assessed the site dimensional and three-dimensional waste. Several commenters refer to a characteristics for the purposes of the versions of BRAGFLO occurred only at recent (January 4, 1998) earthquake in PA and use in comparison with EPA’s very high (lithostatic 22) pressures that New Mexico, over 100 miles from the radioactive waste disposal standards would occur seldom if ever in the WIPP site, as an indication of the and WIPP compliance criteria. The repository. (Docket A–93–02, Item V–C– weakness of the WIPP site for disposal results of EPA’s review of the CCA and 1, Section 5) For simulations at the gas purposes. additional information provided by DOE generation rates used in the CCA PA, In the CCA, DOE examined seismicity is provided in CARDs 14, 23, 32 and 33. the two-dimensional BRAGFLO code as part of its features, events, and (Docket A–93–02, Item V–B–2) predicted greater brine inflows than the processes, analyses, and concluded 4. Parameter Values three-dimensional code. (Greater brine earthquakes could be excluded from the inflows could potentially lead to greater PA calculations based on low a. Introduction. Parameters are direct brine releases.) consequences. This conclusion is drawn numerical values or ranges of numerical The EPA also considered how much from a wealth of knowledge about the values used in the PA to describe brine would be consumed in chemical seismic activity and processes in the different physical and chemical aspects reactions. One of DOE’s studies showed region, but is based primarily on the fact of the repository, the geology and that brine is consumed by corroding that the intensity of ground shaking (the geometry of the area surrounding the steel barrels and leaves behind at least primary cause of destruction from an WIPP, and possible scenarios for human 20 percent of the original steel at the earthquake) is significantly less intrusion. Some parameter values are end of 10,000 years for 99 percent of the underground than at the surface. In well-established physical constants, sets of simulated conditions tested in addition, the ductile nature of a salt such as the Universal Gas Constant or the CCA PA. (Docket A–93–02, Item II– deposit makes it deform differently than atomic masses of radionuclides. G–7, p. 2–12) Based on this study, EPA typical hard rocks, so the displacement Parameters also can be physical, concluded that even if the 3D model due to rupture (if any) will be less. The chemical or geologic characteristics that predicted additional brine inflow EPA reviewed DOE’s earthquake DOE established by experimentation. (beyond that predicted in the current 2D (seismic) scenario in the Technical The DOE has also assigned parameters model), this brine will simply be Support Document for 194.14: Content to aspects of human intrusion scenarios, consumed in chemical reactions (i.e., of Compliance Application, Section such as the diameter of a drill bit used corrosion of metal drums), and will not IV.B.4.f. (Docket A–93–02, Item V–B–3) to drill a borehole that might penetrate go to the surface as direct brine releases. The EPA concurs with DOE’s analysis, the repository. In addition, the Agency looked at results that the probability of a release of Section 194.23(c)(4) requires detailed of additional simulations that DOE radionuclides from the repository due to descriptions of data collection conducted to compare BRAGFLO 2D the opening of fracture pathways caused procedures, data reduction and analysis, and 3D results. (Docket A–93–02, Item by an earthquake is very small. and code input parameter development. IV–G–34, Attachment 1 and February Many years of seismological Section 194.14(d) requires DOE to 25, 1998, memorandum) DOE’s results monitoring, microseismal studies and describe the input parameters to the PA show that the use of a two dimensional geologic study demonstrate that there and to discuss the basis for their representation does not result in an are no probable sources of large selection. Section 194.14(a) requires underestimate of direct brine release earthquakes at or near the WIPP site. DOE to describe the characteristics of during human intrusion. In all cases (Docket A–93–02, Item II–G–1, Chapter the WIPP site, including the natural and investigated, the two dimensional 2.6) The only sources of significant engineered features that may affect the simulations consistently predict either earthquakes in the region lie far to the performance of the disposal system, the same or higher repository pressures west of the site along the Rio Grande rift which is part of the process of and brine saturations than their or to the south along major plate parameter development. corresponding three-dimensional tectonic features in Mexico, although The Agency reviewed the CCA, simulations, leading to larger releases. measurable earthquakes have occurred parameter documentation, and record The Agency, therefore, concludes that closer to the WIPP. (Docket A–93–02, packages for approximately 1,600 the two-dimensional BRAGFLO code Item II–G–1, Chapter 2 and Appendix parameters used as input values to the results in conservative estimates of SCR) Micro-earthquakes (magnitude 3.0 CCA PA calculations. The EPA further releases from the repository compared or smaller on the Richter scale), most of reviewed parameters record packages to results from a three-dimensional which are too small to be felt, or small, and documentation in detail for 465 model. shallow teleseismal ground motion parameters important to performance of related to distant earthquakes are the the disposal system. The Agency 22 Lithostatic pressure is the pressure exerted by only seismicity expected at the WIPP selected parameters to review in depth overlying rock layers. site during the very short period that the based on the following criteria: Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27377

• Parameters that were likely to subject of many public comments, Kd values are derived directly from the contribute significantly to releases or especially related to distribution results of a number of experiments (e.g., 23 seemed to be poorly justified; coefficients (Kd values). In DOE’s crushed rock, column tests) conducted • Parameters that control various conceptual model the Culebra is with brine solutions that are functions of the CCA PA computer characterized as a fractured dolomite representative of brines in the disposal codes that were likely to be important that has dual-porosity and acts to system. The DOE used samples of the to calculations of releases and important physically retard movement of Culebra Dolomite and brine solutions to compliance with the containment contaminants. In a dual-porosity rock that are considered to be representative requirements of § 191.13; and unit, ground water is believed to flow of the field situation. These data were • Other parameters EPA used to through the fractures, but water and supplemented by experiments with evaluate the overall quality of Sandia contaminants can access the pore space other natural dolomites and column National Laboratory’s (‘‘SNL’’) within the rock matrix away from the experiments, in which the effects of a documentation traceability. fractures. Movement of water and field-realistic solid to solution ratio After its initial review, EPA found contaminants into the pore space slows could be investigated. The laboratory- that DOE had a great deal of (retards) their respective forward derived Kd values are expected to documentation available in the SNL movement. This physical retardation is overestimate the mobilities of the Records Center supporting most of the necessary in order to have chemical actinides, making them reflective of parameters used in the CCA PA. retardation. In the process of chemical upper bounds for predicting the However, EPA had some concerns about retardation, contaminants diffuse from maximum possible rates of actinide the completeness of the list of CCA PA the fractures into the pore space where migration in the PA calculations. parameters in the CCA and the SNL they can adsorb onto the rock mass. Therefore, it is reasonable to expect that Records Center, the description and This adsorption is described by the range of actinide Kd values obtained justification to support the development distribution coefficients, or Kd values. from the DOE experiments are inclusive of some code input parameters, and the The CCA indicated that there were no of any scale-effects that might produce traceability of data reduction and contributions to total releases from the a different average Kd value than the analysis of parameter-related records. ground water pathway. (Docket A–93– experimental average in either the The Agency did not agree with the 02, Item II–G–1, Chapter 2) This was greater or lesser directions. Docket A– technical justification of some due to the limited amount of 93–02, Item V–B–4, Section 4.4 presents parameter values and probability contaminated brine predicted to reach EPA’s analysis of field Kd testing. distributions. the Culebra and the fact that The DOE’s experimental results show The Agency later required DOE to radionuclides adsorbed into the Culebra that each of the actinides tested is perform additional calculations in a dolomite did not move with the ground adsorbed to the rock matrix to varying Performance Assessment Verification water flow. That is, the movement of the extents; hence, they will not migrate as Test (‘‘PAVT’’) in order to verify that the radionuclides were retarded with fast as the overall rate of horizontal cumulative impact of all required and respect to the ground water flow. The water flow (i.e., the actinides will be other corrections to input parameters, estimate of the extent of the retardation attenuated). These results are consistent conceptual models, and computer codes (i.e., the Kd value) was based on with general theories of the adsorptive used in the PA was not significant laboratory tests using crushed rocks and behavior of cationic solutes under enough to necessitate a new PA. The small columns of rock. (CCA, Docket A– alkaline pH conditions. EPA directed DOE to incorporate 93–02, Item II–G–1, Chapter 6) The EPA reviewed DOE’s actinide Kd modified values or distributions for The EPA reviewed DOE’s Kd values in values and concluded that the twenty-four parameters in the PAVT. detail. (Docket A–93–02, Item V–B–4) population of Kd values determined in (Docket A–93–02, Item II–I–27) The Based upon the review of DOE’s data, DOE experiments was not well- PAVT showed that the calculated methodologies, and conclusions, EPA represented by a uniform distribution. releases may increase by up to three proposed that the Kd ranges suggested The Agency recommended that a times from those in the original CCA by DOE were sufficient for the PA. (62 loguniform distribution be used in the PA, but that the WIPP is still an order FR 58799) The EPA also concluded that PA calculations. In the PAVT, of magnitude below the containment the laboratory tests were conducted loguniform distributions for the actinide # requirements in § 191.13. The DOE appropriately and that the Kd values Kd values were used. (WPO 47258; satisfied EPA’s concerns about the DOE derived from this testing are Docket No A–93–02, Item II–G–39) The parameters by incorporating EPA’s reasonable, given the experimental results of PAVT still resulted in changes to the parameter values and evidence, and sufficient for PA compliance with regulatory release parameter distributions in the PAVT. purposes. (Docket A–93–02, Item V–B– limits. Therefore, EPA determined that During the public comment period on 2, CARD 14, Section 14.B.5) the CCA PA was adequate for the the proposed rule, members of the Commenters stated that DOE’s purpose of determining compliance. public expressed concern about a few experiments did not produce Kd values (Docket A–93–02, Item V–B–4) specific parameters used in the PAVT: that are representative of conditions in The DOE also performed bounding distribution coefficients (Kd), the the Culebra. The DOE data on actinide calculations using the minimum Kd permeability of borehole plugs, the values necessary to achieve compliance characteristics of a potential brine 23 Dissolved waste migrating out of the disposal with EPA limits. The bounding pocket, and the solubility of different site would migrate as atoms with a positive estimates were obtained for plutonium actinide ions in brine. Commenters electrical charge, or cations; these could be cation (239Pu) and americium (241Am), which species such as Pu∂4 or U∂6. When liquid such as stated these particular parameters could brine carries the cations through sediment or rock, are critical actinides with respect to have an especially great impact on some of the cations become attached to the surface releases to the accessible environment. releases, and therefore, on the results of of these solids. Therefore, the cations travel more Results of DOE’s bounding assumptions the PA. slowly than the liquid as a whole. The rate of (whereby all other factors are set to the advance of the cation as the liquid migrates can be b. Distribution Coefficient (Kd). As the described with a number called a retardation factor. least favorable value) indicate that a Kd primary radionuclide pathway during Distribution coefficients, or Kd’s, are used in of 3 milliliter per gram (ml/g) is an intrusion, the Culebra was the calculating the retardation factor. sufficient for compliance for 239Pu and 27378 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

241Am. Estimates based on typical CCA additional information on MgO used in the PA computer codes. The sample sets indicate that Kd values processes and the peer review panel DOE determined that the available greater than 1 ml/g are sufficient for later concluded that MgO processes will experimental data for the oxidation state compliance. (A higher Kd value indeed take place as initially postulated +IV actinides (i.e., plutonium, uranium, indicates greater retardation—or less by DOE. The EPA concluded that DOE’s and neptunium) were insufficient for movement—of radionuclides.) The Kd qualitative justification was sufficient to making such comparisons. However, the ranges determined from DOE column show that the emplacement of MgO experimental procedures for experiments, conducted since backfill in the repository will help determining the solubilities of +IV submission of the CCA, for 239Pu and prevent or substantially delay the actinide solids are not substantially 241Am are typically greater than 100 ml/ movement of radionuclides toward the different from those used to determine g, thus inferring that Kd values used in accessible environment by helping to the solubilities of +III and +V actinide the PA are more than sufficient to maintain alkaline conditions in the solids. Therefore, EPA concluded that ensure compliance with EPA limits with repository, which in turn favors lower the uncertainties determined for the +III respect to accessible environment actinide solubilities. Furthermore, and +V actinide solids would be release through the Culebra. For these DOE’s bounding of pH levels to a inclusive of those that would be reasons, the actinide Kd values narrow range greatly reduces the obtained for +IV actinide solids, which developed by DOE are considered to be uncertainty associated with pH and are based on experimental adequate for representing actinide actinide solubility in the PA. Refer to measurements of thorium oxide. This mobilities in the PA calculations. CARD 24, Section 24.B.6, and CARD 44 expectation is based on the fact that (Docket A–93–02, Item V–B–2, CARD for further discussion of the effects of DOE used the outermost limits of the 14, Section 14.G.5) MgO. (Docket A–93–02, Item V–B–2) differences between model results and The EPA reviewed and responded to The EPA received numerous experimental results for all data the public comments on Kd values and comments regarding DOE’s lack of a examined to define the breadth of the finds the Kd values used in the PA are sensitivity analysis on the effects of uncertainty limits. This procedure sufficient. Refer to EPA Technical organic ligands and that organic ligands greatly expands the size of the Support Document for Section 194.14: other than ethylene diaminetetraacetic uncertainty bounds beyond what might Assessment of Kd Values Used in the acid (‘‘EDTA’’) should have been be calculated from statistical treatment CCA for EPA’s detailed review. (Docket considered. Organic ligands are of the distribution of the differences. A–93–02, Item V–B–4) important since they can increase more (Docket A–93–02, Item V–B–2, CARD c. Actinide Solubility. Actinide mobile fractions, i.e., can make more 24, Section 24.B.6; and Item V–B–17) solubilities are used in the computer radionuclides available for transport. The EPA therefore finds that the codes to calculate the actinide Organic chemicals are expected to be uncertainty bounds on actinide concentrations released from the part of the waste, especially because solubility are adequate for use in the repository. They are important because many were used in the separation of PA. as radionuclides dissolve in brine, they actinides during chemical processing of Finally, commenters raised issues are more easily released from the nuclear materials. DOE’s bounding regarding the limitations of the disposal system through direct brine calculations and incorporation of oxidation state analogy in the Actinide release mechanisms. Commenters uncertainty ranges to represent actinide Source Term Dissolved Species Model. questioned the analysis of certain concentrations in the PA calculations In short, the actinide oxidation analogy chemical conditions in the disposal indicate that organic ligands will have means that actinides of the same system relating to backfill, ligands, only a minor effect on the solubilities of oxidation state tend to have similar uncertainty, and oxidation state actinide solids under the expected chemical properties under similar analogy. repository conditions. The EPA found, conditions. The oxidation state analogy An important factor influencing through independent calculations, that is based on standard inorganic actinide solubility is the magnesium there is no substantive information that chemistry principles. This oxide (MgO) backfill DOE proposed to could be gained by conducting a generalization can be made because emplace in the WIPP. The DOE sensitivity analysis on the effects of chemical reactions involving ionic indicated that MgO backfill emplaced organic ligands or conducting the species are related primarily to the with transuranic waste would mitigate calculations with citrate rather than charge densities of the reacting species. the solubility-enhancing effects of EDTA, since EDTA provides a Actinides with the same oxidation state carbon dioxide from waste degradation. conservative assessment of the effects of have the same core electronic structure; The DOE proposed to emplace a large ligands on solubility of actinide solids. hence they have similar ionic radii and amount of MgO in and around waste (Docket A–93–02, Item V–B–2, CARD charge densities, which in turn leads to drums in order to provide an additional 24, Section 24.E.5) The EPA agrees with analogous chemical behavior in factor of safety and thus account for the conclusions of the Waste solubility and aqueous speciation uncertainties in the geochemical Characterization Independent Review reactions. In addition to the theoretical conditions that would affect CO2 Panel ‘‘that under the conditions of basis, DOE conducted experimental generation and MgO reactions. MgO backfill, chelating agents (e.g., studies that confirmed the validity of Commenters stated that DOE has not organic ligands) will have a negligible the oxidation state analogy, and shown the predicted MgO chemical effect on repository performance. The subsequently employed it in its processes will take place. The DOE Panel notes that, even at the basic pH in representation of the solubilities of provided documentation in the CCA the repository, the availability of actinides. The EPA finds that the and supplementary information that transition metals may be enhanced due actinide oxidation state is adequate for MgO can effectively reduce actinide to the formation of soluble halo use in the PA. (Docket A–93–02, Item solubility in the disposal system. While complexes, making an even stronger V–B–2, CARD 24, Section 2.B.6) the conceptual model peer review panel case that base metals control ligand For details regarding chemical initially rejected DOE’s chemistry.’’ reactions of MgO, see CARD 24 (Waste conceptualization of the Chemical Commenters also expressed concern Characterization) and CARD 44 Conditions Model, DOE provided about the solubility uncertainty range (Engineered Barriers). For further Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27379 information regarding the PA modeling study using the Time Domain WIPP site are known to be dry. In view of solubility and chemical conditions in Electromagnetic (‘‘TDEM’’) method. In of the lack of support from the TDEM the repository, see CARD 23 (Models addition, EPA found there was data and the other concerns expressed and Computer Codes). CARDs can be considerable uncertainty in this above, EPA concludes that available found in Docket A–93–02, Item V–B–2. parameter. Therefore, in the PAVT the data do not support a 100 percent d. Brine Pockets. The Castile Agency required DOE to change the probability of hitting a brine pocket. Formation lies underneath the Salado constant value of this parameter to a The EPA established its 1 percent to Formation, where the WIPP is located. uniform probability distribution from 1 60 percent range of probability for This stratum contains pockets of brine percent to 60 percent, based upon data hitting a brine pocket based upon data under pressure. One of the parameters in the TDEM study. (Docket A–93–02, from the TDEM survey. The Agency in the PA that commenters believed to Item II–I–27) examined the data and found that the be important is the probability that a Many commenters questioned the use probability distributions for driller will hit a brine pocket in the of a uniform distribution from 1 percent encountering brine under the WIPP Castile. The CCA PA models the to 60 percent as the range for the varied widely, depending on whether or possibility that a drill bit could probability of hitting a brine pocket that not one assumed that brine pockets exist penetrate a brine pocket in the Castile EPA specified be used in the PAVT. below the bottom of the Anhydrite III Formation, allowing brine to rise up the Some believed that EPA should require layer near the top of the Castile borehole and into the repository. The DOE to examine a probability of 100 Formation. Using the base of the brine could then dissolve radioactive percent for hitting a brine pocket, based anhydrite layer as the cutoff, EPA’s waste and could carry it to the earth’s upon data from DOE’s WIPP–12 simulations showed that the fraction of surface if another driller bored a hole borehole, which suggested that a large the excavated area of the repository into the repository. This could increase reservoir of brine might lie in the Castile underlain by brine varies from 1 to 6 the amount of radioactive waste Formation under the WIPP Land percent of the excavated area. Using the reaching the accessible environment. Withdrawal Area. Others recommended base of the Castile as the cutoff, the Some commenters expressed concern that EPA require DOE to repeat the PA fraction of the excavated area of the that brine from brine pockets in the assuming a constant probability of 60 repository underlain by brine would Castile Formation could travel up to the percent. range from about 35 to 58 percent. level of the repository, or even to the The EPA carefully evaluated the According to the 1992 WIPP PA, Castile earth’s surface. The EPA believes that potential occurrence of brine pockets Formation brines are generally found in this is not a problem unless the below the WIPP. The EPA agrees that the uppermost anhydrite layer (usually repository is disturbed by human there is significant uncertainty Anhydrite III), rather than all the way intrusion. Because it is difficult for concerning the existence of a brine through the Castile. (Docket A–92–03, water to travel in the Salado and Castile pocket beneath the repository. For this Item II–G–1, CCA Reference #563, Vol. formations (i.e., they have low reason, EPA required DOE to reevaluate 3, p. 5–4) If brine is confined to the permeability), there is no natural the probability of hitting a brine pocket upper (Anhydrite III) layer, which is the connection between a Castile brine in the PAVT using a probability more probable case based on geologic pocket and the waste panel area under distribution rather than a constant information, the maximum fraction of undisturbed conditions. These brines value. the repository area underlain by brine is are also either saturated or nearly The EPA also considered the 6 percent. However, in order to examine saturated with soluble minerals such as possibility that the brine pocket the possible effects of the more salt (halite), and thus, the brine in indicated by WIPP–12 data may conservative case, EPA chose to assume pockets will not dissolve the underlie 100 percent of the repository. an equal probability that a driller would surrounding material. (Docket A–93–02, Based on reservoir volume and hit a brine pocket in either the upper Item II–G–1, CCA Chapter 2, Table 2–5) thickness data from WIPP–12, Anhydrite III layer or the base of the However, in the case of a deep drilling commenters found that a cylindrically- Castile. Therefore, EPA used a intrusion that goes through a waste shaped reservoir could underlie the probability range in the PAVT with a panel and into the Castile, it is possible entire repository. However, EPA low value of 1 percent based on the that the driller will intercept brine in considers this unlikely because brine in upper anhydrite layer and the high the Castile and create a pathway for the Castile does not reside in value of 60 percent derived by rounding Castile brine to flow into the repository homogeneous and well-defined up the highest value from the TDEM and interact with the waste. The reservoirs. Instead, it is believed to survey. The EPA believes that existing probability of human intrusion through reside in vertical or subvertical fracture information supports the range used in the WIPP repository to an underlying systems, which may be extensive and the PAVT as valid, and probably Castile brine pocket is a key component contain significant volumes of brine. conservative, values for the probability of the PA. (Docket A–93–02, Item II–G–1, of hitting a brine pocket. The 1992 draft PA considered the Appendix MASS, Attachment 18–6) The Agency also notes that a probability of a driller hitting a brine Although EPA agrees that part of the sensitivity analysis of the PA parameters pocket under the waste area with a WIPP–12 reservoir may underlie part of submitted in comments showed that the range of 25 percent to 62 percent, based the repository, the time-domain final results of the PA were not on geophysical work that suggested electromagnetic (‘‘TDEM’’) survey data significantly affected by increasing the brine may be present. (Docket A–93–02, do not support speculation of a 100% probability of hitting a brine pocket. Item II–G–1, Reference #563) In the CCA probability of an encounter. (Docket A– Even when the Castile brine encounter PA, DOE assigned a probability of 93–02, Item II–G–1, Chapter 2.2.1.2.2, probability was increased to 100 hitting a brine pocket of 8 percent, Item V–B–3, section IV; Item V–B–14, percent’the highest possible based upon a geostatistical analysis of Sections 4.1, 4.4, and 4.5) In addition, probability’there was no significant oil and gas wells in the vicinity of as pointed out by one of the commenters difference between the resulting mean WIPP. The Agency believed that the recommending a probability of 60 CCDF and the mean CCDF in the CCA, assigned probability was low, based percent, some boreholes adjacent to which was based upon a brine upon data from one particular DOE brine-producing boreholes near the encounter probability of 8 percent. 27380 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

(Docket A–93–02, Item IV–G–43) The PA, DOE modeled a situation in which than the constant permeability used in EPA believes that 100 percent is an borehole plugs between the Castile and the CCA. In addition, EPA required DOE unrealistically high probability. The Bell Canyon Formations would remain to use a range of permeability values to results of this study confirm that impermeable, and most borehole plugs represent the permeability of borehole examining such a probability in more closer to the earth’s surface would plugs that have started to degrade. The detail would provide little added disintegrate after two hundred years and upper end of the new range was the information about the performance of would become more permeable. same permeability as that used in the the WIPP. One commenter stated that the CCA CCA, but the lower end of the range was Commenters stated that the range of does not model the gas buildup which reduced by three orders of magnitude the compressibility of rock surrounding would result from impermeable plugs. and the median was reduced by an a Castile brine pocket used in the CCA The EPA does not agree that the CCA order of magnitude. The Agency PA was too wide. They also believed does not model gas buildup. In the CCA believed that the upper end of the range that the brine pocket volume values PA and PAVT, gas pressure is allowed chosen by DOE, based upon the used in the PA were too small. Castile to build up in the undisturbed permeability of silty sand, was rock compressibility is one of several repository. Pressure would be released if reasonable because an abandoned parameters that affects the volume of a borehole is drilled into the repository. borehole plug could degrade to this type brine pockets in the Castile. This is In some of the PA simulations, pressure of debris over long periods of time. important because a drill bit would be builds up again, although not to Since the permeability of the actual more likely to hit a large brine pocket undisturbed levels, after it is released borehole fill material at some time well than a small one. during a borehole intrusion. (Docket A– into the future is unknowable, the The EPA agrees with commenters that 93–02, Item II–G–7, Figure 3.3.1) Agency believes that the use of data DOE’s parameters for rock However, EPA was concerned about based on natural materials is a compressibility in the Castile and DOE’s assumption that a relatively small reasonable approach. However, the representation of brine pocket size/ number of borehole plugs would have Agency was not satisfied with the volume in the CCA PA were not low permeability. In the CCA PA, DOE rationale for the lower end of the range consistent with available information. assumed that 98 percent of the originally chosen by DOE. The EPA The EPA also believes that the boreholes would be plugged with either believes that there is some probability parameters of the Castile brine pockets two or three plugs, where the top plug that the concrete borehole plugs will not are highly uncertain. In order to capture would degrade and become more degrade as assumed in the CCA PA. this uncertainty, the Agency believed it permeable, and 2 percent of the Consequently, in the PAVT, EPA set the would be appropriate to sample from a boreholes were plugged with a single lower end of the range at a permeability range of parameter values, rather than to low permeability plug. The EPA was value consistent with intact concrete. use a single estimate, as DOE did in the concerned that an assumption that only One commenter stated that DOE had CCA PA. In the PAVT, EPA required 2 percent of the boreholes had low not sufficiently accounted for DOE to use a range of possible brine permeability might not be conservative. uncertainty in the lifetime of a borehole pocket volumes. (WPO#41887. See Therefore, EPA required that the plug before it degrades. (A borehole Docket A–93–02, Item V–B–1. See also permeability range for borehole plugs in plug with a longer lifetime would take Docket A–93–02, Item V–B–14.) the PAVT be broadened to include longer to become more permeable and Changing the rock compressibility of the lower values (at which gas will not would allow more gas to build up in the Castile and the Castile porosity escape at a significant rate). This repository.) This commenter stated that effectively modified the sampled brine parameter change ensured that the DOE should perform additional pocket volume to include, more PAVT would more frequently calculations to investigate how borehole representatively, the possibility of larger incorporate low borehole permeability plug lifetimes could influence brine pocket volumes like those and gas pressure buildup for more repository conditions and compliance expected based on data from the WIPP– simulations than in the CCA PA, with the containment requirements. 12 borehole. The EPA found that providing a more conservative result. The EPA also initially had concerns modification of these parameters in the Other commenters expressed concern that uncertainty about the lifetime of PAVT did not result in releases that that the borehole plug permeabilities borehole plugs had not been sufficiently exceed EPA’s containment standards. used in the CCA PA and the PAVT were represented in the CCA PA. In order to Based on these results, EPA has too high, and might underestimate reflect this uncertainty, the Agency concluded that the CCA PA was releases of radioactive material from the required DOE to use a probability adequate for the purpose of WIPP. One commenter pointed out that distribution of borehole plug demonstrating compliance. EPA retained the permeability used by permeabilities for intact plugs during e. Permeability of Borehole Plugs. In DOE as a high value and then added a the first two hundred years of their the PA modeling, DOE assumed that range of permeabilities extending to lifetime in the PAVT, rather than a people drilling for resources would lower values after the Agency rejected constant value. The sampled range of follow standard practice and plug the DOE’s initial value as too high. permeabilities includes values boreholes left behind. As long as these In the PAVT, EPA required that two representing the permeability of both borehole plugs remain intact, the changes be made regarding the intact (newer) plugs and disintegrating pressure of gases generated from the permeability of the borehole plugs. (older) plugs. Therefore, EPA believes waste will build up inside the First, the Agency required that the that this change made in the PAVT repository. The more permeable the permeability of the intact plugs during adequately addresses the effects of borehole plugs are, the more gas will be the first two hundred years of the plug uncertainty in borehole plug life. capable of escaping from the repository. lifetime be treated as a variable or This would reduce pressure in the probability distribution rather than as a 5. Other Performance Assessment Issues repository and therefore would reduce fixed parameter, with a range bounded The EPA used many methods to the potential for releases of radioactivity by values found in the literature. The analyze specific scenarios or through spallings or direct brine release range of values included borehole plug characteristics that DOE included in the from a future drilling event. In the CCA permeabilities both higher and lower PA. Commenters had concerns about Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27381 these methods, since the soundness of concern about 58 parameters of the 465 testing sensitivity related in any EPA’s conclusions would depend upon parameters that EPA reviewed in detail. particular way to the compliance the soundness of the methods used to (Docket A–93–02, Item II–I–17) For demonstration with the containment reach those conclusions. Commenters these 58 parameters, EPA evaluated requirements. This commenter also disagreed with aspects of a few types of whether changing the parameter values stated that EPA had not explained or analyses in particular: sensitivity would have a significant impact on the justified why the analysis used the analysis, and the PA verification test results of computer modeling, primarily average of changes in the outputs of the (‘‘PAVT’’). Sensitivity analysis is a through the use of a sensitivity analysis. submodels, and that averaging output computer modeling technique that (Docket A–93–02, Item V–B–13) changes might disguise the significance examines whether results of computer (Distribution coefficients, or Kd values, of a parameter value change if some modeling will change significantly if a were examined in separate calculations outputs change in direct response and particular parameter value is changed. and analyses conducted by EPA. others change inversely. The EPA’s approach to sensitivity (Docket A–93–02, Items V–B–4, V–B–7, The DOE’s PA model uses almost analysis is documented in EPA’s and V–B–8)) In its sensitivity analysis, 1600 parameters. Even an important Technical Support Document for the Agency examined changes in output parameter may change the final results Section 194.23: Sensitivity Analysis. from the PA models’ major submodels of the PA by a relatively small (Docket A–93–02, V–B–13) The PAVT that calculate releases and solubility of percentage because so many parameters was a set of 300 simulations of actinides: BRAGFLO 24, BRAGFLO— contribute to the final results. The additional performance assessment DBR 25, CUTTINGS—S 26, SOURCE different submodels contain far fewer calculations required by EPA. The TERM 27, and CCDFGF 28. The EPA parameters than the complete PA. PAVT implemented DOE’s PA modeling found that 27 of the 58 parameters have Therefore, a change in any one using the same sampling methods as the a significant impact on the results of parameter will cause a greater CCA PA, but incorporating parameter modeling and that 31 of the 58 percentage change in the output from a values that were selected by EPA. parameters did not have a significant submodel than in the final result of the Because some commenters disagreed impact. Some of these parameters (both entire PA modeling. It is for this reason with DOE’s approach to the PA and significant and insignificant to results) that EPA chose to use submodels. This EPA’s approach to its analysis, they were subsequently determined to be approach provided intermediate results recommended that the Agency require adequately supported based on that would be a more sensitive measure DOE to repeat the PA using different additional documentation provided by of reactions of a model to changes in scenarios or characteristics of the WIPP DOE or Sandia National Laboratory. input parameters than the resultant and its surroundings; these issues are (Docket A–93–02, Items II–I–25 and II– complementary cumulative distribution discussed in preceding sections of this I–27) For parameters that might have an functions (‘‘CCDFs’’) used to determine preamble related to the PA. impact on the results of the PA and compliance. a. Sensitivity Analysis. Computer were found not to be adequately The submodel outputs that EPA modelers perform a sensitivity analysis supported, EPA required DOE to analyzed for sensitivity included the for a parameter in a model to find out perform a Performance Assessment outputs most closely linked with if results of modeling are sensitive to Verification Test with revisions to the radionuclide release and the ability of (significantly affected by) that significant parameters. the WIPP to meet EPA’s containment parameter. If the results of modeling are Commenters stated that they had requirements. Examples of submodel not sensitive to the parameter, then the concerns about the submodel approach outputs are gas pressure in the exact value of the parameter is not used in EPA’s sensitivity analysis. One repository; cumulative brine release into important to the results of modeling. commenter stated that EPA had not the Culebra dolomite; cumulative The compliance criteria require DOE justified this approach, beyond stating cavings release and cumulative to document the development of input that it was ‘‘a more sensitive method’’ spallings release to the earth’s surface; parameters for the PA under than examining the final results of the and brine flow into the anhydrite §§ 194.14(d), 194.23(c)(4), and complete PA model. Another interbeds away from the repository. If a 194.34(b). As part of its parameter commenter stated that EPA had not parameter changes the submodel development, DOE conducted a shown that the submodel approach for outputs significantly, it may have a sensitivity analysis of parameters used significant impact on the final results of in the CCA PA. (Docket A–93–02, Item 24 BRAGFLO predicts gas generation rates, brine the PA; however, if a parameter does not II–G–1, Appendix SA, Volume XVI) The and gas flow, and fracturing within the anhydrite change the submodel output EPA reviewed this and supplementary marker beds in order to predict the future state of significantly, then it cannot change the the repository. information that documents DOE 25 BRAGFLO—DBR calculates the amount of final results of the PA significantly. In sensitivity analysis of the parameters waste that dissolves in brine and travels in the addition, EPA notes that the nature of sampled in the PA. (Docket A–93–02, contaminated brine as a direct brine release. the testing—which included three Item II–G–7) As the Agency continued 26 CUTTINGS—S predicts the volume of solid model runs at low, average, and high in its review of the CCA and supporting waste released from the repository because of parameter values—means that it is not human intrusion drilling. This includes releases documentation, EPA found that there from cavings (material that falls from the walls as practical to develop mean CCDFs. It were three categories of parameters not a drill bit drills through), cuttings (material that is would be necessary to run all of the PA fully documented in the CCA actually cut by a drill bit during drilling, including codes for each parameter change a documents or in the Sandia National any waste), and spallings (releases of solids pushed hundred times to create a single CCDF. Laboratory WIPP Records Center. These up and out by gas pressure in the repository). Therefore, except for those parameters 27 SOURCE TERM calculates actinide solubilities categories were: (1) parameters lacking within the repository. The solubility values are then included in the CCDFGF code, it would supporting evidence; (2) parameters used in the NUTS and PANEL codes to calculate have been extremely cumbersome and having data records that support values the actinide concentrations in brine released from time-consuming to perform a sensitivity other than those selected by DOE; and the repository. analysis on the final results of the PA. 28 CCDFGF calculates the complementary, (3) parameters that are not explicitly cumulative distribution functions (‘‘CCDFs’’) used The Agency disagrees that averaging supported by the relevant data or to show compliance with EPA’s containment the submodel outputs disguises the information. The EPA expressed requirements. significance of a parameter value change 27382 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations if some outputs change in direct these insensitive parameters is so small 194.23(a)(3)(v). The Agency finds that it response and others change inversely. compared to the sensitive parameters. is not necessary to perform further The EPA used absolute values 29 of the For example, the sum of the percent sensitivity analysis on conceptual percent changes in computing the changes for all 33 insensitive parameters models because both the Agency’s and average percent changes. If two in BRAGFLO together was 47 percent the Panel’s reviews accomplished the parameters had inverse relationships, (ranging from 0 percent to 10 percent purpose of evaluating the impact of those relationships would not cancel each), while the percent change for the using different assumptions or using each other out because the final results individual sensitive parameters ranged alternative conceptual models. These would be an average of the absolute from 101 percent to 103,611 percent reviews found all the conceptual models values. Averaging of the percent each. (Docket A–93–02, Item V–B–13, except the spallings model to be changes in the key submodel outputs Table 3.1–1) Therefore, EPA concluded adequate for use in the PA, and was a significant step only for the that those parameters it found concluded that the spallings values used parameters in the BRAGFLO code, insensitive through analysis of in the CCA PA are reasonable for use in where average changes to output were individual parameters will not have a the PA. (Docket A–93–02, Item V–B–2, developed based on 11 model outputs. significant effect on results of the PA CARD 23, Section 7) The EPA averaged the results of these and do not need to be re-analyzed in The EPA determined that DOE eleven outputs in order to give equal groups. adequately provided a detailed listing of weight to each in determining the In addition to performing its own the code input parameters; listed sensitivity of BRAGFLO parameters. sensitivity analysis on parameters, the sampled input parameters; provided a Several members of the public Agency required DOE to complete a description of parameters and the codes commented that most of the sensitivity comprehensive recalculation of the in which they are used; discussed analyses varied only one parameter, entire PA in the Performance parameters important to releases; rather than varying several parameters Assessment Verification Test (‘‘PAVT’’). described data collection procedures, at a time, which potentially could show The purpose of the PAVT was to sources of data, data reduction and a significant combined result. The EPA perform a complete evaluation of the analysis; and described code input varied single parameters in most of the synergistic effects of changing important parameter development, including an analyses to identify those parameters and questionable parameters on the explanation of quality assurance that were most important to the PA outcome of the PA calculations. The activities. The DOE also documented results. One of the problems with results of the PAVT indicate that the the probability distribution of these varying multiple parameters calculated releases would increase parameters, as required by § 194.34(b). simultaneously is that it is difficult to when changes are made to the sensitive The Agency analyzed parameter values determine which parameter (or parameters identified by the Agency, used in the CCA, including DOE’s parameters) led to the observed result. but the revised results of the PA with documentation of the values and EPA’s Analysis of groups of parameters these more conservative parameter sensitivity analysis. The EPA also requires the Agency to find that the values would still be an order of required DOE to change these parameter entire group of parameters is sensitive magnitude less than the containment values in the PAVT and found that the or not sensitive. In addition, if some requirements of 40 CFR 191.13. WIPP is still an order of magnitude parameters in a group increase releases A commenter stated that EPA’s below the containment requirements in while others reduce releases, a group sensitivity analysis did not vary § 191.13. (For further discussion of analysis may not detect actual conceptual models. The Agency agrees values for several specific parameters, sensitivity for individual parameters. that this is true. The objective of EPA’s refer to the preceding preamble This is because the sensitivity analysis sensitivity analysis was to determine the discussion, ‘‘Parameter values.’’ See also typically looks at low, high, and average importance of selected individual Docket A–93–02, Item V–B–2, CARD 23, values for all parameters in the group parameters and groups of parameters to Sections 8 and 9.) Therefore, the Agency simultaneously. Without examining the the PA results. The purpose of a determines that the CCA complies with sensitivity of individual parameters, the sensitivity analysis on conceptual §§ 194.14(d), 194.23(c)(4) and 194.34(b). models would be to determine if model b. Performance Assessment analyst would not always know enough results would change significantly using Verification Test. The containment about the parameters to be able to different assumptions or using requirements at § 191.13 indicate that a predict the most extreme situation with alternative conceptual models. The EPA disposal system is to be tested through the greatest consequences of releases. examined the conceptual models and a PA that predicts the likelihood of The ability to determine the significance alternatives, under §§ 194.23(a)(1) and occurrence of all significant processes of individual parameters is important (a)(2). As a result of this review, EPA and events that may disturb the disposal because this allows one to improve the required DOE to conduct a sensitivity system and affect its performance, and model’s predictive capability by analysis on Culebra transmissivity and that predicts the ability of the disposal focusing resources on those parameters to examine the assumption that the system to contain radionuclides. Section that are most sensitive and have the Culebra acts as a fully confined system 191.13 requires that a disposal system greatest impact on results. It is true that as it pertains to hydrogeochemistry of be designed so that there is reasonable EPA did not perform a separate the Culebra. (Docket A–93–02, Item II– expectation that cumulative releases (1) sensitivity analysis run on groups of I–17) The EPA found that the sensitivity have a probability of less than one in ten parameters that it determined were analysis results supported DOE’s (0.1) of exceeding the calculated release insensitive through individual treatment of Culebra transmissivity and limits, and (2) have no more than a one parameter tests. The Agency believes treatment of the Culebra as a confined in one thousand (0.001) chance of that this is not necessary because the system because of the minimal impact exceeding ten times the calculated cumulative calculated sensitivity of on results when changing assumptions. release limits. (Docket A–93–02, Item II–I–31) In In the process of reviewing the CCA, 29 Absolute value is the magnitude of a number, without a positive or negative sign. For example, addition, the Conceptual Models Peer the Agency found problems with some positive three and negative three both have an Review Panel reviewed the conceptual computer codes and with absolute value of three. models, as required by §§ 194.27 and documentation of parameter Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27383 development. Commenters also voiced brine and gas in the repository. Many sensitivity analysis showed that this concerns about some parameters used in commenters stated that the Agency parameter did not have a significant the CCA PA during the public comment should require DOE to run another PA impact on WIPP compliance at still period for the Advanced Notice of using different assumptions about these higher values. A different commenter Proposed Rulemaking. The Conceptual topics. stated that DOE and EPA should analyze Models Peer Review Panel initially The EPA initially had many of the actinide solubilities as if DOE were not found that one of the conceptual models same concerns as those mentioned by adding MgO to reduce those solubilities, used for the PA, the spallings the public, particularly concerning even though the Department has conceptual model, was not adequate. parameters and human intrusion committed to adding MgO. The Agency The DOE itself found some problems scenarios. As discussed in the above found all of these suggestions to be with some of its codes, particularly preamble sections on the PA, EPA inappropriate, either because they were concerning code stability. Because of questioned the values and distributions unrealistic or because they required these many concerns, the Agency of many values of the parameters. The additional analysis when the change required DOE to perform additional Agency even required DOE to revise had already been demonstrated to have calculations in a Performance some parameter values for the PAVT. little or no impact on the PA results. Assessment Verification Test (‘‘PAVT’’) The EPA also asked DOE to investigate The Agency believes that the PA should in order to verify that the cumulative fluid injection further. After receiving be a reasonable assessment with some impact of all changes to input public comments, the Agency did conservative assumptions built in, parameters, conceptual models, and independent work on the possible rather than an assessment comprised computer codes used in the PA was not impacts of fluid injection and air entirely of unrealistic assumptions and significant enough to necessitate a new drilling, as well as analysis of the worst-case scenarios. The disposal PA. (PAVT, Docket A–93–02, Items II– likelihood of air drilling and CO2 regulations at 40 CFR Part 191 require G–26 and II–G–28) The PAVT used injection in the Delaware Basin. (Docket the PA to show there is a reasonable modified parameter values and ranges, A–93–02, Item V–C–1, Sections 5 and 8) expectation that cumulative releases selected by EPA, in DOE’s PA model. After reviewing the information will meet the containment Many of these parameter values were available, the Agency concludes that requirements. This philosophy is suggested by public comments. The DOE’s PA incorporates the appropriate reflected elsewhere in EPA’s PAVT results showed releases that were human intrusion scenarios and geologic requirements, such as in the higher, on average, than DOE’s original and disposal system characteristics. The requirement for the mean CCDF to calculations in the CCA. However, the PAVT and additional analyses of comply with the containment PAVT results were still well within the intrusion scenarios by both DOE and requirement, rather than for every CCDF EPA release limits stated in 40 CFR EPA have adequately addressed to comply. If unrealistically 191.13. concerns raised by commenters. conservative assumptions were used in Based upon results of the CCA PA (as the PA, then results of the PA would not During the public comment period on confirmed by the PAVT), EPA finds that reflect reality and would not be a EPA’s proposed certification decision the WIPP complies with the reasonable measure of the WIPP’s for the WIPP, commenters raised several containment requirements by a capability to contain waste. issues about the PAVT and about the PA comfortable margin, even when using in general. Some commenters stated that more conservative parameter values that 6. Conclusions the PAVT incorporated extremely were changed significantly from those Section 194.23 sets forth specific conservative ranges for 24 critical in the CCA PA. This modeling shows requirements for the models and parameters, and that the PA in general that the WIPP will contain waste safely computer codes used to calculate the was done in a conservative fashion. under realistic scenarios, and even in results of performance assessments Other commenters stated that specific many extreme cases. The EPA found (‘‘PA’’) and compliance assessments. In parameter values needed to be changed that the scenarios and parameter order for these calculations to be in order to make more conservative changes suggested by commenters either reliable, DOE must properly design and assumptions. In particular, the public had already been adequately addressed implement the computer codes used in mentioned parameters for actinide by DOE, were inappropriate for the the PA. To that end, § 194.23 requires solubility, distribution coefficients (Kd), Delaware Basin, would impact neither DOE to provide documentation and the probability of hitting a brine pocket, releases nor the results of the PA descriptions of the PA models, and the permeability of borehole plugs. sufficiently to justify further analysis, or progressing from conceptual models (These parameters are discussed above.) were not realistic. Therefore, the Agency through development to mathematical Commenters also said that DOE needed concludes that no further PA is required and numerical models, and finally to to investigate possible human intrusion to determine if the WIPP is safe or to their implementation in computer scenarios more thoroughly. Among the make its certification decision. codes. human intrusion scenarios commenters Many comments were based on a The CCA and supporting documents identified for further study were air philosophy that DOE should use an contain a complete and accurate drilling, fluid injection, CO2 injection, unrealistically conservative approach to description of each of the conceptual and potash mining. Members of the the PA. For example, a commenter models used and the scenario public commented that DOE had stated that air drilling should be construction methods used. The incorrectly assessed geology of the WIPP incorporated in the PA at the most scenario construction descriptions site and the future state of the waste to conservative rate predicted by DOE in include sufficient detail to understand go into the WIPP. They stated concerns the near future for the entire U.S., even the basis for selecting some scenarios about the potential for dissolution, for if air drilling is not currently a standard and rejecting others and are adequate for the recharge of ground water in the practice in the Delaware Basin. Another use in the CCA PA calculations. Based Rustler Formation with contaminated commenter suggested using the most on information provided in the CCA, brine, for earthquakes, and for water conservative value from the PAVT for together with supplementary entering the Salado layer and the the probability of hitting a brine pocket, information provided by DOE in modeling of gas generation and flow of even after the commenter’s own response to specific EPA requests, EPA 27384 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations concluded that DOE provided an error problems and stability problems sources of data, data reduction and adequate and complete description of identified in numerical models by analysis; and described code input alternative conceptual models seriously completing code revisions and parameter development, including an considered but not used in the CCA. supplementary testing requested by the explanation of QA activities. The EPA The information on peer review in the Agency. Therefore, the Agency determined that the CCA and CCA and in supplementary information concludes that DOE has demonstrated supplementary information adequately demonstrates that all conceptual models compliance with §§ 194.23(a)(3) (ii), (iii) discussed how the effects of parameter have undergone peer review consistent and (iv). correlation are incorporated, explained with the requirements of § 194.27. Based on EPA audits and CCA review, the mathematical functions that Related issues discussed above in EPA found that code documentation describe these relationships, and today’s preamble include spallings, meets the quality assurance described the potential impacts on the fluid injection, air drilling, CO2 requirements of ASME NQA–2a–1990 sampling of uncertain parameters. The injection, and the gas generation addenda, part 2.7, to ASME NQA–2– CCA also adequately documented the conceptual model. The Agency 1989 edition. Thus, the Agency finds effects of parameter correlation for both determines that the DOE has that DOE complies with § 194.23(b). conceptual models and the formulation demonstrated compliance with the Based on DOE’s documentation for of computer codes, and appropriately requirements of §§ 194.23 (a)(1), (a)(2) each code and supplementary incorporated these correlations in the and (a)(3)(v). information requested by EPA, the PA. Public comments regarding The Conceptual Models Peer Review Agency found that DOE provided parameters are discussed above in the Panel found all the conceptual models adequate documentation so that preamble in the section titled to reasonably represent possible future individuals knowledgeable in the ‘‘Parameter Values.’’ The Agency finds states of the repository and to be subject matter have sufficient that DOE has demonstrated compliance adequate for use in the PA except the information to judge whether the codes with the requirements of § 194.23(c) (4) spallings conceptual model. However, are formulated on a sound theoretical and (6). as discussed above in this preamble, foundation, and whether the code has Because DOE provided EPA with additional modeling conducted by DOE, been used properly in the PA. The EPA ready access to the necessary tools to and additional data presented by DOE, found that the CCA and supplementary permit EPA to perform independent provide a substantial basis for EPA to information included an adequate simulations using computer software conclude that the results of the spallings description of each model used in the and hardware employed in the CCA, model are adequate and useful for the calculations; a description of limits of EPA finds DOE in compliance with purpose for which conceptual models applicability of each model; detailed § 194.23(d). are intended, i.e., to aid in the instructions for executing the computer Section 194.31 of the compliance determination of whether the WIPP will codes; hardware and software criteria requires DOE to calculate release comply with the disposal regulations requirements to run these codes; input limits for radionuclides in the WIPP in during the regulatory time period. and output formats with explanations of accordance with 40 CFR Part 191, Public comments received on this issue each input and output variable and Appendix A. Release limits are to be are discussed above in the preamble parameter; listings of input and output calculated using the activity, in curies, section on spallings. Because the files from sample computer runs; and from radioactive waste that will exist in spallings model produces reasonable reports of code verification, bench the WIPP at the time of disposal. The and conservative results, and because marking, validation, and QA CCA PA and the PAVT were calculated the Peer Review Panel found that all procedures. The EPA also found that using release limits calculated according other conceptual models reasonably DOE adequately provided a detailed to Appendix A of 40 CFR Part 191 using represent possible future states of the description of the structure of the DOE’s projected inventory of waste repository, EPA finds DOE in computer codes and supplied a radioactivity at the time of disposal. compliance with § 194.23(a)(3)(i). complete listing of the computer source Therefore, EPA concludes that DOE has Based on information contained in the code in supplementary documentation met the requirements of § 194.31. CCA and supporting documentation for to the CCA. The documentation of Section 194.32 requires DOE to each code, EPA concludes that the computer codes describes the structure consider, in the PA, both natural and mathematical models used to describe of computer codes with sufficient detail man-made processes and events which the conceptual models incorporate to allow EPA to understand how can have an effect on the disposal equations and boundary conditions software subroutines are linked. The system. The EPA expected DOE to which reasonably represent the code structure documentation shows consider all features, events and mathematical formulation of the how the codes operate to provide processes (‘‘FEPs’’) that may have an conceptual models. Some of the specific accurate solutions of the conceptual effect on the disposal system, including issues related to this criterion are in the models. The EPA finds that DOE did not both natural and human-initiated section of the preamble entitled, ‘‘Two- use any software requiring licenses. processes. The Department is not dimensional modeling of brine and gas Therefore, EPA determines that DOE has required to consider FEPs that have less flow.’’ Based on the CCA and complied with the requirements of than one change in 10,000 of occurring supplementary information provided by §§ 194.23(c) (1),(2),(3) and (5). over 10,000 years. DOE, the Agency determines that DOE The EPA determined that DOE, after The EPA concluded that the initial provided sufficient technical additional work and improvement of FEP list assembled by DOE was information to document the numerical records in the SNL Record Center, sufficiently comprehensive, in models used in the CCA. Based on adequately provided a detailed listing of accordance with §§ 194.32(a) and (e)(1). verification testing, EPA also the code input parameters; listed Based on quantitative and qualitative determined that the computer codes sampled input parameters; provided a assessments provided in the CCA and accurately implement the numerical description of parameters and the codes supporting documents, EPA concluded models and that the computer codes are in which they are used; discussed that DOE appropriately rejected those free of coding errors and produce stable parameters important to releases; FEPs that exhibit low probability of solutions. The DOE resolved coding described data collection procedures, occurrence during the regulatory period, Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27385 in accordance with § 194.32(d). In appropriately screened out shallow § 194.34. The PAVT presented the addition, EPA found DOE’s inclusion of drilling from consideration in the PA. results of the PA in CCDFs, and various scenarios in the PA to be The EPA also found that DOE presented the complement of 300 reasonable and justified, and meets the appropriately incorporated the CCDFs. DOE’s documentation and requirement of § 194.32(e)(2). The DOE assumptions and calculations for EPA’s separate analysis demonstrated provided documentation and drilling into the PA as stipulated in that 300 CCDFs are sufficient, justification for eliminating those FEPs §§ 194.33 (b) and (c). In accordance with statistically speaking. The PAVT used that were not included in the PA. In § 194.33(c), DOE evaluated the the same random sampling technique of some cases (e.g., fluid injection, CO2 consequences of drilling events Latin Hypercube Sampling that the PA injection, potash mining and assuming that drilling practices and model used for the CCA PA. The DOE dissolution), the CCA did not initially technology remain consistent with used parameter values assigned by EPA, provide adequate justification or practices in the Delaware Basin at the as well as other parameter values and convincing arguments to eliminate FEPs time the certification application was their distributions documented earlier from consideration in the PA. However, prepared. Public comments concerning for the CCA PA. The mean CCDF curve DOE provided supplemental this issue are discussed in the preamble for the PAVT showed that releases were information and analyses, which EPA section above titled, ‘‘Air drilling.’’ The roughly three times those calculated in determined was sufficient to EPA determined that the PA models did the CCA PA, but releases still met the demonstrate compliance with not incorporate the effects of techniques containment requirements of § 191.13 § 194.32(e)(3). used for resource recovery, as allowed by more than an order of magnitude at The EPA verified, through review of by § 194.33(d). The EPA further the required statistical confidence level. the CCA and supporting documents, concludes that the drilling information Less than ten percent of CCDF curves in that DOE included, in the PA, in the CCA is consistent with available the PAVT exceeded one times the appropriate changes in the hydraulic data. Therefore, the Agency finds DOE release limit, and no CCDF curves conductivity values for the areas in compliance with the requirements of exceeded ten times the release limit. affected by mining. The area considered § 194.33. The PAVT confirmed that the CCA PA to be mined for potash in the controlled Section 194.34 of the compliance was adequate for determining area is consistent with the requirement criteria provides specific requirements compliance. Therefore, EPA concludes of § 194.32(b), that the mined area be for presenting the results of the PA for that the CCA PA meets EPA’s based on mineral deposits of those the WIPP. Section 194.34 requires DOE containment requirements and that DOE resources currently extracted from the to use complementary cumulative complies with the requirements of Delaware Basin. Thus, EPA finds that distribution functions (‘‘CCDFs’’) to § 194.34. DOE complies with § 194.32(b). express the results of the PA. The In accordance with § 194.32(c), DOE Department also must document the C. General Requirements considered the possibility of fluid development of probability 1. Quality Assurance (§ 194.22) injection, identified oil and gas distributions, and the computational exploration and exploitation, and water techniques used for drawing random Section 194.22 establishes quality and potash exploration as the only near samples from these probability assurance (‘‘QA’’) requirements for the future human-initiated activities that distributions, for any uncertain WIPP. QA is a process for enhancing the need to be considered in the PA. The parameters used in the PA. The PA must reliability of technical data and analyses EPA’s review of the CCA and supporting include a statistically sufficient number underlying DOE’s CCA. Section 194.22 documents referenced in the CCA with of CCDFs. The CCA must display the requires DOE to (a) establish and respect to § 194.32(c), indicated that full range of CCDFs generated. Finally, execute a QA program for all items and DOE adequately analyzed the possible the CCA must demonstrate that the activities important to the containment effects of current and future potential mean of the population of CCDFs meets of waste in the disposal system, (b) activities on the disposal system. In the containment requirements of qualify data that were collected prior to response to concerns expressed by EPA § 191.13 with at least a 95 percent level implementation of the required QA and stakeholders, DOE conducted of statistical confidence. program, (c) assess data for their quality additional analyses and submitted The CCA presented the results of the characteristics, to the extent practicable, follow-up information. In addition, EPA PA in the form of CCDFs. The PA used (d) demonstrate how data are qualified has performed its own analysis of fluid Latin Hypercube Sampling to sample for their use, and (e) allow verification injection. Public comments concerning values randomly from probability of the above measures through EPA human intrusion FEPs are discussed in distributions of uncertain parameters. inspections/audits. The DOE’s QA the preamble sections above titled, Parameter values and their distributions program must adhere to specific Nuclear ‘‘Fluid injection,’’ ‘‘Potash mining,’’ and were documented in the CCA and in Quality Assurance (‘‘NQA’’) standards ‘‘CO2 injection.’’ The collected Sandia National Laboratory’s Records issued by the American Society of information provided by DOE was Center. The CCA presented the full Mechanical Engineers (‘‘ASME’’). adequate. Therefore, EPA concludes that range of the 300 CCDFs generated in the The EPA assessed compliance with DOE’s analysis meets the requirements PA, as well as mean CCDF curves. The the QA requirements in two ways. First, of § 194.32(c). CCDFs showed that the mean CCDF EPA reviewed general QA information Section 194.33 requires DOE to make curve met the containment requirements submitted by DOE in the CCA and specific assumptions about future deep of § 191.13. Less than one percent of reference documents. The EPA’s second and shallow drilling in the Delaware CCDF curves in the CCA PA exceeded level of review consisted of visits to the Basin. The EPA found that the one times the release limit, and no WIPP site, as well as WIPP-related documentation in the CCA CCDF curves exceeded ten times the facilities, to perform independent audits demonstrated that DOE thoroughly release limit. Based on these results, and inspections to verify DOE’s considered deep and shallow drilling DOE concluded that the WIPP met compliance with the QA requirements. activities and rates within the Delaware EPA’s requirements. The proper establishment and execution Basin in accordance with § 194.33 (a) The EPA also examined the results of of a QA program is verified strictly by and (b). The EPA found that DOE the PAVT in light of the requirements of way of inspections and audits. 27386 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

Therefore, EPA conducted audits to as it applies to waste characterization, is With respect to other waste generator verify the proper execution of the QA in conformance with the NQA sites, EPA will verify compliance with program at DOE’s Carlsbad Area Office requirements and that DOE’s QA § 194.22(a)(2)(i) conditioned on (‘‘CAO’’), Sandia National Laboratories organization can properly perform separate, subsequent approvals from (‘‘SNL’’), and Westinghouse’s Waste audits to internally check the QA EPA that site-specific QA programs for Isolation Division (‘‘WID’’) at the WIPP programs of the waste generator sites. waste characterization activities and facility. The EPA auditors observed However, as discussed below, the assumptions have been established and WIPP QA activities, interviewed WIPP Agency will verify the establishment executed in accordance with applicable personnel, and reviewed voluminous and execution of site-specific QA NQA requirements at each waste records required by the NQA standards, programs. generator site. but not required to be submitted as part The compliance criteria require that As waste generator facilities establish of the CCA. QA programs be established and QA programs after LANL, EPA will Section 194.22(a)(1) requires DOE to executed specifically with respect to the assess their compliance with NQA adhere to a QA program that use of process knowledge and a system requirements. The approval process for implements the requirements of the of controls for waste characterization. site-specific QA programs includes a following: (1) ASME NQA–1–1989 (§§ 194.22(a)(2)(i) and 194.24(c)(3) Federal Register notice, public edition; (2) ASME NQA–2a–1990 through (5)) To accomplish this, waste comment period, and on-site EPA audits addenda, part 2.7, to ASME NQA–2– generator site-specific QA programs and or inspections to evaluate 1989 edition; and (3) ASME NQA–3– plans must be individually examined implementation. For further information 1989 edition (excluding Section 2.1 (b) and approved by EPA to ensure on EPA’s approval process, see and (c), and Section 17.1). The EPA adequate QA programs are in place Condition 2 and § 194.8. For further verified that DOE established these before EPA allows individual waste discussion of waste characterization requirements in the Quality Assurance generator sites to transport waste for programs and approval of the processes Program Document (‘‘QAPD’’) contained disposal at the WIPP. Since waste used to characterize waste streams from in the CCA. The QAPD is the characterization activities have not generator sites, see the discussion of documented QA program plan for the begun for most TRU waste generator § 194.24 below in this preamble. WIPP project, as a whole, to comply sites and storage facilities, EPA has not Section 194.22(a)(2)(ii) requires DOE with the NQA requirements. The QAPD yet evaluated the compliance of many to include information which is implemented by DOE’s CAO, which site-specific QA plans and programs. demonstrates that the QA program has has the authority to audit all other To date, one WIPP waste generator been established and executed for organizations associated with waste site, Los Alamos National Laboratory environmental monitoring, monitoring disposal at the WIPP (such as WID, SNL (‘‘LANL’’), has been approved by EPA to of performance of the disposal system and waste generator sites) to ensure that have established an adequate QA and sampling and analysis activities. their lower-tier QA programs establish program plan and to have properly Westinghouse’s WID was responsible for and implement the applicable executed its QA program in accordance requirements of the QAPD. The EPA establishing this requirement under the with the plan. Prior to approval of WID QAPD described in the CCA. The audited DOE’s QA program at CAO and LANL’s site-specific QA program, EPA determined that DOE properly adhered EPA conducted an audit of the WID and conducted an audit of DOE’s overall found that the requisite QA program to a QA program that implements the WIPP QA program and approved its NQA standards. Therefore, EPA finds had been established and executed for capability to perform audits in environmental monitoring, sampling DOE in compliance with § 194.22(a)(1). accordance with the requirements of Section 194.22(a)(2) requires DOE to and analysis activities. The EPA also NQA–1. The EPA then inspected three include information in the CCA that finds that Chapter 5 of the CCA and DOE audits of LANL’s QA program. demonstrates that the requisite QA referenced documents contain a Based on the results of the inspections, program has been ‘‘established and satisfactory description of compliance the EPA inspectors determined that the executed’’ for a number of specific with this section. Therefore, EPA finds QA program had been properly activities. Section 194.22(a)(2)(i) the WIPP in compliance with executed at LANL.31 Therefore, EPA requires DOE to include information § 194.22(a)(2)(ii). finds that the requirements of which demonstrates that the QA Section 194.22(a)(2)(iii) requires DOE § 194.22(a)(2)(i) have been met for waste program has been established and to include information which characterization activities at LANL. executed for waste characterization demonstrates that the QA program has activities and assumptions. In the CCA, been established and executed for field DOE provided the QAPD, which is referred to as a ‘‘quality assurance program plan,’’ measurements of geologic factors, or ‘‘QAPP.’’ For WIPP waste generator sites, the role ground water, meteorologic, and DOE’s central QA document program of the QAPP is fulfilled by documents with other plan that then must be incorporated into titles, such as the QAP and the QAPjP. The ‘‘TRU topographic characteristics. WID is site-specific QA program plans. The QAPP’’ referenced by DOE in the CCA is not a responsible for conducting field DOE generator sites will prepare site QAPP as described by the NQA standards; rather, measurements of geologic factors, it is a technical document that describes the quality ground water, meteorologic and certification Quality Assurance Plans control requirements and performance standards for (‘‘QAPs’’) that, together with Quality characterization of TRU waste coming to the WIPP topographic characteristics. The EPA Assurance Project Plans (‘‘QAPjPs’’), facility. The TRU QAPP is addressed more conducted an audit of the WID QA specifically in the preamble discussion of § 194.24, program and found it to be properly will constitute site-specific QA program Waste Characterization. 30 established and executed in accordance plans. The EPA finds that the QAPD, 31 The terms ‘‘audits’’ and ‘‘inspections’’ are not synonymous. At waste generator sites, EPA may with the applicable NQA requirements. 30 NQA–1 (Element II–2) requires that either conduct its own audits or inspect audits The EPA also finds that Chapter 5 of the organizations responsible for activities affecting conducted by DOE. (The DOE–CAO conducts audits CCA and referenced documents contain quality (in the case of the WIPP, affecting the to evaluate waste characterization programs at a satisfactory description of compliance containment of waste in the disposal system) must waste generator sites.) The difference is that for an have documented QA programs in accordance with inspection, EPA’s role is to review DOE’s QA with this section. Therefore, EPA finds the applicable NQA requirements. The checks, and not actually conduct all of the checks DOE in compliance with documentation for such programs is commonly itself. § 194.22(a)(2)(iii). Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27387

Section 194.22(a)(2)(iv) requires DOE established and executed. The EPA also since the level of such reviews was to include information to demonstrate finds that Chapter 5 of the CCA and equivalent to NUREG–1297 peer that the QA program has been referenced documents contain an reviews conducted by DOE. Therefore, established and executed for adequate description of compliance EPA finds DOE in compliance with computations, computer codes, models with this section. Therefore, EPA finds § 194.22(b). Furthermore, the Agency is and methods used to demonstrate DOE in compliance with approving the use of any one of the compliance with the disposal § 194.22(a)(2)(vi). following three methods for regulations. SNL and WID are Section 194.22(a)(2)(vii) requires DOE qualification of existing data: (1) peer responsible for computations and to include information which review, conducted in a manner that is software items. The EPA reviewed demonstrates that the QA program has compatible with NUREG–1297; (2) a QA information in the CCA and conducted been established and executed for the program that is equivalent in effect to audits of both SNL and WID QA collection of data and information used ASME NQA–1–1989 edition, ASME programs. The Agency found that to support compliance applications. NQA–2a–1990 addenda, part 2.7, to computer codes were documented in a SNL was responsible for this activity. ASME NQA–2–1989 edition, and ASME manner that complies with the SNL adequately addressed these NQA–3–1989 edition (excluding Section applicable NQA requirements, and that requirements by implementing 2.1(b) and (c) and Section 17.1); or (3) software QA procedures were numerous QA procedures to ensure the use of data from a peer-reviewed implemented in accordance with ASME quality of data and information technical journal. NQA–2a, part 2.7. The EPA also finds collected in support of the WIPP. The Sections 194.22(c)(1) through (5) that Chapter 5 of the CCA and EPA’s audit of SNL concluded that the require DOE to provide information referenced documents contain a QA program is properly established and which describes how all data used to satisfactory description of compliance executed. Therefore, EPA finds DOE in support the compliance application with this section. The EPA therefore compliance with § 194.22(a)(2)(vii). have been assessed, to the extent finds that DOE complies with Section 194.22(a)(2)(viii) requires practicable, for specific data quality § 194.22(a)(2)(iv). DOE to include information which characteristics (‘‘DQCs’’). In the CCA, Section 194.22(a)(2)(v) requires DOE demonstrates that the QA program has DOE stated that in most cases it was not to include information which been established for any other item or practicable to document DQCs for demonstrates that the QA program has activity not listed above that is performance assessments, but asserted been established and executed for important to the containment of waste that the intent of DQCs was fulfilled by procedures for implementation of expert in the disposal system. The DOE has not other QA programs and quality control judgment elicitation. CAO and CAO’s identified any other item or activity measures. Technical Assistance Contractor were important to waste isolation in the The Agency agrees with DOE that it responsible for developing the disposal system that require QA is not appropriate to apply DQCs procedures for the expert elicitation that controls to be applied as described in retroactively to all of the parameters and was conducted (after the publication of the CAO QAPD. To date, the EPA has existing data used in the PA, but the CCA). The EPA found that the also not identified any other items or believes that they can and should be requirements of this regulation were met activities which require controls. The applied to measured data (i.e., field by the development and EPA audits determined that the QA monitoring and laboratory experiments) implementation of CAO Team organizations of CAO, WID, and SNL as they are developed and used. The Procedure 10.6 (Revision 0), CAO Team have sufficient authority, access to work EPA found that, because DOE deemed it Plan for Expert Panel Elicitation areas, and organizational freedom to impractical to apply DQCs in some (Revision 2), and CAO Technical identify other items and activities instances, the CCA and supplementary Assistance Contractor Experimental affecting the quality of waste isolation. information did not systematically or Programs Desktop Instruction No.1 Therefore, EPA finds DOE in adequately address DOE’s consideration (Revision 1). The EPA finds DOE in compliance with § 194.22(a)(2)(viii). of DQCs for measured data related to the compliance with § 194.22(a)(2)(v). The Section 194.22(b) requires DOE to PA. Therefore, EPA reviewed parameter process of expert judgment elicitation is include information which records to determine whether DOE discussed in further detail in the section demonstrates that data and information could in fact show that various data of this preamble related to § 194.26 of collected prior to the implementation of quality characteristics had been the compliance criteria. the QA program required by considered for measured data. The Section 194.22(a)(2)(vi) requires DOE § 194.22(a)(1) have been qualified in Agency reviewed additional materials, to include information which accordance with an alternate primarily data record packages at the demonstrates that the QA program has methodology, approved by the SNL records center, to independently been established and executed for Administrator or the Administrator’s determine whether DQCs had been design of the disposal system and authorized representative, that employs assessed for data used in the PA. The actions taken to ensure compliance with one or more of the following methods: EPA found that for recent data (five to the design specifications. Most of the peer review; corroborating data; ten years old), DOE’s experimental WIPP’s design was conducted before the confirmatory testing; or a QA program program plans in the data record EPA required a QA program. Design that is equivalent in effect to packages generally addressed data work for the repository sealing system § 194.22(a)(1) ASME documents. quality in measured data, including was conducted under the SNL QA The EPA conducted two audits that accuracy, precision, representativeness, program. The QA procedures traced new and existing data to their completeness, and comparability during established and implemented by SNL qualifying sources. The two audits measurement and collection. and WID address the requirements of found that equivalent QA programs and For older existing data, EPA found the NQA standards; design verification peer review had been properly applied less documentation of assessment of was accomplished by a combination of to qualify existing data used in the PA. DQCs. However, laboratory NQA–1 Supplement 3S–1 methods. The The EPA also concluded that the use of notebooks’which provide first-hand EPA audits of SNL and WID showed existing data from peer-reviewed documentation of measurement that the QA programs are properly technical journals was appropriate, procedures and results’supporting data 27388 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations record packages provided some generated a table providing information in the eight areas of § 194.22(a)(2). The information related to the quality of of how all data in the PA were qualified. CCA states that DOE provides the measurements (e.g., how well DOE’s The EPA audited the existing QA overall QA program requirements for measured values compared with values programs and determined that the data WIPP via the CAO QAPD. The CAO found in peer-reviewed publications). were qualified for use by independent QAPD requirements are further Many existing data were also subject to and qualified personnel in accordance supported and amplified by the next tier peer review in order to qualify them for with NQA requirements. On this basis, of QA program documents, which use in the CCA; EPA concluded that the EPA finds DOE in compliance with includes the SNL quality assurance peer review panels considered the use § 194.22(d). procedures (SNL QAPs), the WID of DQCs in determining that such data Section 194.22(e) allows EPA to verify Quality Assurance Program Description, were adequate. The EPA also agreed execution of QA programs through and the individual site quality with DOE’s argument in supplementary inspections, record reviews, and other assurance program plans (e.g., QAPjPs). information that for most of the existing measures. As discussed above, EPA has More documentation is found in DOE, data, collection under a program conducted numerous audits of DOE WID and SNL implementing procedures equivalent to the NQA standards in facilities, and intends to conduct future and QA records. For example, § 194.22(a)(1) provided adequate inspections of waste generator site- ‘‘Corrective Action Reports’’ and ‘‘Audit evidence that the quality of data had specific QA plans under its authority. Reports’’ provide objective evidence of been evaluated and controlled. Finally, The Agency also intends to conduct implementation of certain NQA EPA concurred with DOE’s conclusion inspections or audits to confirmed elements. Therefore, EPA finds that that the uncertainties in measured data DOE’s continued adherence to QA sufficient information for compliance reflected in DQCs have a small effect on requirements for which EPA is with § 194.22(a)(2)(ii)–(viii), and for QA compliance certainty, compared to other certifying compliance. program implementation for waste uncertainties in the PA (such as In summary, EPA finds DOE in characterization activities at LANL extrapolation of processes over 10,000 compliance with the requirements of (§ 194.22(a)(2)(i)) was provided in the years). § 194.22 subject to the condition that CCA and supporting documents to the The EPA found that data quality EPA separately approve the extent practical. received considerable attention from establishment and execution of site- The EPA verified that QA programs peer reviewers and Independent Review specific QA programs for waste were established in accordance with Teams assembled by DOE, and was characterization activities at waste subject to NQA requirements as generator sites. (See Condition 2 of the § 194.22 through the CAO QAPD and specified in the Quality Assurance proposed Appendix A to 40 CFR Part supporting documents. The EPA Program Document (‘‘QAPD’’). Section 194.) expected to find objective evidence of § 194.22(a) requires DOE to implement The EPA received many public compliance or noncompliance with the NQA–3–1989 in its quality assurance comments on § 194.22, but the most QA requirements within the QA records program. NQA–3–1989 states, ‘‘Planning significant issue identified by and activities of the WIPP organizations, shall establish provisions for data commenters was the lack of objective including CAO, SNL, and WID. In quality evaluation to assure data evidence in the CCA to justify meeting accordance with § 194.22(e), the Agency generated are valid, comparable, the requirements at § 194.22(a)(2). The conducted audits of these WIPP complete, representative, and of known comments posed the fundamental organizations to verify the appropriate precision and accuracy.’’ This question of whether or not EPA could execution of QA programs. (Docket A– requirement was satisfactorily certify, based solely on information 93–02; Items II–A–43, II–A–44, II–A–45, incorporated in the QAPD, which is the provided by DOE in the CCA, that DOE II–A–46, II–A–47, II–A–48, and II–A–49) quality assurance ‘‘master’’ document established and executed a QA program Documentation of evidence of audits that establishes QA requirements for all for the eight areas considered important that verified the execution of the QA activities overseen by the DOE Carlsbad to the containment of waste in the programs is found in EPA’s audit Area Office. The EPA determined by disposal system. In response to such reports. The EPA’s audits of CAO, SNL, means of audits that DOE adequately concerns, EPA believes it is necessary to and WID covered all aspects of the implemented the requirements of the explain and clarify the verification of programs including, but not limited to: QAPD, and also determined that DOE these QA requirements. the adoption of the requirements of adequately qualified existing data in The CCA does not alone provide all § 194.22 through the CAO QAPD, accordance with Section § 194.22(b). the documentation to verify compliance quality assurance procedures (‘‘QAPs’’), (See Docket A–93–02, Item V–B–2, with the requirement of § 194.22(a)(2). reports from previous audits, CARD 22, Sections 22.A.6 and 22.J.5.) Section § 194.22(e) requires EPA to surveillance reports, and corrective Therefore, EPA finds that DOE’s data verify that DOE has established and action reports (‘‘CARs’’). The audits qualification was sufficiently rigorous to executed a QA program for the areas assessed the adequacy and account for the DQCs identified in the indicated in § 194.22(a)(2). The implementation of the SNL and WID WIPP compliance criteria. ‘‘objective evidence’’ for determining quality assurance programs in Based on its review of data record whether or not a QA program has been accordance with the requirements of packages and the QAPD, the Agency established and executed exists at the § 194.22(a)(1). For example, for finds that DOE has assessed DQCs, to WIPP-related facilities and generator § 194.22(a)(2)(iv), the ‘‘computations, the extent practicable, for data used in sites, and is gathered in the field audits computer codes, models and methods the CCA. The EPA thus finds that DOE and inspections. The function of the used to demonstrate compliance with complies with § 194.22(c). The Agency audits and inspections is to gather the disposal regulations,’’ EPA expects that DOE will assess DQCs for objective evidence to determine conducted audits of the SNL and WID future waste characterization and compliance of the QA programs with quality assurance programs for monitoring activities. the applicable NQA standards. computations, computer codes, methods Section 194.22(d) requires DOE to Several WIPP organizations are and models. For all of the other areas in provide information which describes responsible for establishing and § 194.22(a)(2), CARD 22 (Section 22.B) how all data are qualified for use. SNL executing the activities and items listed should be consulted for information and Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27389 citations to audit reports. (Docket A–93– parameters or in conceptual models: the PA, DOE took no credit for the 02, Item V–B–2) solubility, formation of colloidal potential gas-reducing effects of solid In summary, EPA certifies compliance suspensions containing radionuclides, waste (i.e., assumed a lower limit of with the eight areas in § 194.22(a)(2) gas generation, shear strength of waste, zero) and demonstrated that the WIPP through inspections and audits. Most of radioactivity of specific isotopes, and would still comply. For nitrates and the evidence demonstrating compliance transuranic (‘‘TRU’’) activity at disposal. sulfates, EPA determined that these is found at the WIPP-related facilities The DOE identified eight waste components would not significantly and generator sites. Such evidence was components influencing the six affect the behavior of the disposal unreasonable to include in the CCA due significant waste characteristics: ferrous system as long as cellulosics were to the voluminous nature of the metals, cellulose, radionuclide limited. Thus, EPA concurred that it is information. identification, radioactivity of isotopes, unnecessary to specify limits for 2. Waste Characterization (§ 194.24) TRU activity of waste, solid waste components, sulfates, and nitrates. nitrates, sulfates, and solid waste. Section 194.24, waste Finally, DOE provided a list of waste The EPA finds DOE in compliance characterization, generally requires DOE characteristics and components with § 194.24(c)(1). The EPA concurred to identify, quantify, and track the assessed, but determined not to be with DOE that it was not necessary to chemical, radiological and physical significant for various reasons such as provide estimates of uncertainty for components of the waste destined for negligible impact on the PA. The EPA waste limits, so long as the PA disposal at the WIPP that can influence found that DOE used a reasonable demonstrated compliance at the fixed disposal system performance. methodology to identify and assess limits. However, since DOE’s waste Section 194.24(a) requires DOE to waste characteristics and components. limits do not address uncertainty, the describe the chemical, radiological and The analysis appropriately accounted physical composition of all existing and Department must account for for uncertainty and the quality of uncertainty in the quantification of to-be-generated waste, including a list of available information. Therefore, EPA waste components and their waste components when tracking finds DOE in compliance with compliance with the waste limits. That approximate quantities in the waste. requirements in § 194.24(b). The DOE provided the required Section 194.24(c)(1) requires DOE to is, the fixed waste limits essentially information on existing waste (35% of specify numeric limits on significant constitute an upper confidence level (in the total WIPP inventory) by combining waste components and demonstrate the case of limits on the maximum similar waste streams into waste stream that, for those component limits, the amount of a waste component) or a profiles. The waste stream profiles WIPP complies with the numeric lower confidence level (in the case of contain information on the waste requirements of §§ 194.34 and 194.55. limits on the minimum amount of a material parameters, or components, Either upper or lower limits were component) for measurements or that could affect repository established for components that must be estimates of waste components that performance. For to-be-generated waste controlled to ensure that the PA results must be tracked. The DOE must (65% of the total WIPP inventory), DOE comply with the containment demonstrate that the characterized extrapolated information from the requirements. The DOE explicitly waste components, including associated existing waste streams to determine the included numeric limits, identified as uncertainty (i.e., margin of error), meet future amount of waste. The EPA fixed values with no associated the fixed waste component limits. reviewed this information and uncertainty, for four waste components. Section 194.24(c)(2) requires DOE to determined that DOE’s waste stream Lower limits were established for (1) profiles contained the appropriate ferrous and (2) non-ferrous metals (not identify and describe the methods used specific information on the components included in DOE’s original list of to quantify the limits of important waste and their approximate quantities in the components, but added later due to its components identified in § 194.24(b)(2). waste. Therefore, EPA finds DOE in binding effect on organic ligands); upper The DOE proposed to use non- compliance with § 194.24(a). limits were established for (3) destructive assay (‘‘NDA’’), non- Section 194.24(b) requires DOE to cellulosics and (4) free water (not destructive examination (‘‘NDE’’), and analyze waste characteristics and waste included in DOE’s original list of visual examination (‘‘VE’’) as the components for their impact on disposal components, but added later due to its methods used to quantify various waste system performance. Waste components inclusion in the Waste Acceptance components. (See Docket A–93–02, Item affect waste characteristics and are Criteria). V–B–2, CARD 24, Section 24.F.1 for integral to disposal system performance. The three components related to further information about the methods.) The DOE identified waste-related radioactivity (radionuclide The DOE described numerous NDA elements pertinent to the WIPP as part identification, radioactivity of isotopes, instrument systems and described the of its screening for features, events, and TRU activity of waste) were effectively equipment and instrumentation found processes. The features, events, and limited by the inventory estimates used in NDE and VE facilities. The DOE also processes used in the performance in the PA and the WIPP LWA fixed- provided information about assessment (‘‘PA’’) served as the basis value limits. Both the PA inventory performance demonstration programs from which characteristics and estimates and the WIPP LWA fixed- intended to show that data obtained by associated components were identified value limits were included in the PA each method could meet data quality and further analyzed. (For further calculations through parameters closely objectives established by DOE. The EPA information on features, events, and related to these components, and the found that these methods, when processes, see Docket A–93–02, Item V– results demonstrated compliance with implemented appropriately, would be B–2, CARD 32; and the above preamble EPA’s standards. adequate to characterize the important sections related to the PA.) Explicit limits were not identified for The DOE concluded that six solid waste, sulfates, and nitrates, even waste components. Therefore, EPA finds characteristics were expected to have a though DOE identified these as DOE in compliance with § 194.24(c)(2). significant effect on disposal system components significant to performance. Section 194.24(c)(3) requires DOE to performance and were used in the PA as For solid waste, EPA determined that in demonstrate that the use of process 27390 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations knowledge 32 to quantify components in embodies this limitation. The site- program had been established and waste for disposal conforms with the specific use of process knowledge must executed at LANL in conformance with quality assurance (‘‘QA’’) requirements conform with QA requirements, as Nuclear Quality Assurance found in § 194.22. The DOE did not addressed by Condition 2. (For further requirements. Moreover, DOE submit site-specific information on the information on EPA’s approval process, demonstrated that the WWIS is process knowledge to be used at waste see § 194.8, ‘‘Approval Process for functional with respect to LANL—i.e., generator sites as part of the CCA. The Waste Shipment from Waste Generator that procedures are in place at LANL for EPA requires such information to Sites for Disposal at the WIPP.’’) adding information to the WWIS conduct proper review of whether use of Sections 194.24(c) (4) and (5) require system, that information can be the process knowledge is appropriate DOE to demonstrate that a system of transmitted from LANL and and reliable. The DOE provided some controls has been and will continue to incorporated into the central database, information on its overall plans for be implemented to confirm that the and that data in the WWIS database can using process knowledge in the CCA. waste components emplaced in the be compiled to produce the types of The DOE did not, however, provide WIPP will not exceed the upper limit or reports described in the CCA for specific information on the use of fall below the lower limit calculated in tracking compliance with the waste process knowledge or Acceptable accordance with § 194.24(c)(1) and that limits. At the same time, DOE Knowledge (‘‘AK’’—hereafter only ‘‘AK’’ the system of controls conforms to the demonstrated that the WWIS is is used; process knowledge is a subset QA requirements specified in § 194.22. functional with respect to the WIPP of acceptable knowledge) at any waste The DOE described a system of controls facility—i.e., that information generator site in the CCA, nor did it over waste characterization activities, incorporated into the central database provide information demonstrating such as the requirements of the TRU QA can be retrieved at the WIPP and establishment of the required QA Program Plan (‘‘TRU QAPP’’) and the compiled to produce reports for tracking programs. Waste Acceptance Criteria (‘‘WAC’’). compliance with the waste limits. After submission of the CCA, EPA The EPA found that the TRU QAPP Therefore, EPA finds DOE in subsequently received information established appropriate technical compliance with §§ 194.24(c)(4) and (5) regarding AK to be used at the Los quality control and performance for legacy debris waste at LANL. (Docket Alamos National Laboratory (‘‘LANL’’). standards for sites to use in developing A–93–02, Items V–B–15 and V–B–2, The EPA determined that DOE site-specific sampling plans. Further, CARD 24) The EPA’s decision is limited adequately described the use of AK for DOE outlined two phases in waste to the waste that can be characterized legacy debris waste at LANL. The EPA characterization controls: (1) waste using the systems and processes audited has confirmed establishment and stream screening/verification (pre- by DOE, inspected by EPA, and found execution of the required QA programs shipment from waste generator site); to be adequately implemented at at that waste generator site through and (2) waste shipment screening/ LANL.33 The EPA does not find, inspections. Therefore, EPA finds that verification (pre-receipt of waste at the however, that DOE has demonstrated DOE has demonstrated compliance with WIPP). The tracking system for waste compliance with § 194.24(c)(4) for any the § 194.24(c)(3) QA requirement for components against their upper and/or other waste stream at LANL, or with LANL. The EPA does not find, however, lower limits is found in the WIPP Waste §§ 194.24(c)(4) and (5) at any other that DOE has adequately described the Information System (‘‘WWIS’’). The EPA waste generator site. use of AK for any waste at LANL other finds that the TRU QAPP, WAC, and For any LANL waste streams using than the legacy debris waste which can WWIS are adequate to control important other characterization processes or any be characterized using the processes components of waste emplaced in the other waste generator site, before waste examined in EPA’s inspection. (See WIPP. The EPA audited DOE’s QA can be shipped to the WIPP, EPA must Docket A–93–02, Item V–B–15 for programs at Carlsbad Area Office, determine that the site has implemented further information on the conclusions Sandia National Laboratory and a system of controls at the site, in of EPA’s inspection. See Docket A–93– Westinghouse Waste Isolation Division accordance with § 194.24(c)(4), to 02, Item II–I–70 for a list of the items and determined that DOE properly confirm that the total amount of each and processes inspected by EPA.) adhered to QA programs that implement waste component that will be emplaced Furthermore, DOE has not demonstrated the applicable Nuclear Quality in the disposal system will not exceed compliance with § 194.24(c)(3) for any Assurance standards and requirements. the upper limiting value or fall below other waste generator site. For any (See the preamble discussion of the lower limiting value described in LANL waste streams using other § 194.22, Quality Assurance, for further the introductory text of paragraph (c) of characterization processes or any other information.) However, in the CCA, § 194.24. The implementation of such a waste generator site, before waste can be DOE did not demonstrate that the WWIS system of controls shall include a shipped to the WIPP, EPA must is fully functional and did not provide demonstration that the site has determine that the site has provided information regarding the specific procedures in place for adding data to information on how AK will be used for system of controls to be used at the WWIS, and that such information waste characterization of the waste individual waste generator sites. can be transmitted from that site to the stream(s) proposed for disposal at the After submission of the CCA, EPA WWIS database; and a demonstration WIPP. Condition 3 of the final rule subsequently received information that measurement techniques and regarding the system of controls control methods can be implemented in 32 Process knowledge refers to knowledge of waste (including measurement techniques) to accordance with § 194.24(c)(4) for the characteristics derived from information on the be used at LANL. The Agency materials or processes used to generate the waste. confirmed through inspections that the This information may include administrative, 33 See Docket A–93–02, Item II–I–70 for a list of procurement, and quality control documentation system of controls—and in particular, the systems and processes audited by DOE. See associated with the generating process, or past the measurement techniques—is Docket A–93–02, Item II–I–51 for a description of sampling and analytic data. Usually, the major adequate to characterize waste and the waste identifier and a discussion of the items elements of process knowledge include information ensure compliance with the limits on and activities inspected by EPA. They include about the process used to generate the waste, characterization methodologies and relevant material inputs to the process, and the time period waste components for some waste procedures, such as that used for entering data into during which the waste was generated. streams, and also confirmed that a QA the WWIS database. Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27391 waste stream(s) proposed for disposal at pre-receipt (at the WIPP). The DOE into waste characterization activities for the WIPP. Condition 3 prohibits DOE stated that the WWIS will be used to a particular waste stream (or group of from shipping waste for disposal at track specific data related to each of the waste streams) at a generator site, and WIPP until EPA has approved site- WIPP LWA limits; by generating routine (2) DOE has demonstrated that the specific waste characterization programs WWIS reports, DOE will be able to system of controls described in and controls. The system of controls determine compliance with the imposed § 194.24(c)(4) and (5) has been must also be implemented in limits. The WWIS will also be used to established for the site. In particular, accordance with the QA requirements of track information on each of the DOE must demonstrate that the WWIS 40 CFR 194; see Condition 2. (For important waste components for which system is functional for any waste further information on EPA’s approval limits were established. The EPA finds generator site before waste may be process, see § 194.8, ‘‘Approval Process that the WWIS is adequate to track shipped, and that the system of controls for Waste Shipment from Waste adherence to the limits, and that the (including measurement techniques) Generator Sites for Disposal at the WWIS has been demonstrated to be can be implemented for each waste WIPP.’’) fully functional at the WIPP facility; as stream which DOE plans to dispose in Section 194.24(d) requires DOE either discussed above, waste generator sites the WIPP. As discussed in the preamble to include a waste loading scheme will demonstrate WWIS procedures for § 194.22, DOE must also demonstrate which conforms to the waste loading before they can ship waste for disposal that sites have established and executed conditions used in the PA and in at the WIPP. Therefore, EPA finds DOE the requisite QA programs described in compliance assessments, or to assume in compliance with §§ 194.24(e) and (g). §§ 194.22(a)(2)(i) and 194.24(c)(3) and random placement of waste in the Section 194.24(h) allows EPA to (5). disposal system. The DOE elected to conduct inspections and record reviews The EPA received many public assume that radioactive waste would be to verify compliance with the waste comments on § 194.24. The majority of emplaced in the WIPP in a random characterization requirements. As the comments focused primarily on fashion. The DOE examined the possible discussed above, EPA intends to whether or not DOE could adequately effects of waste loading configurations monitor execution of waste characterize waste to be sent to the on repository performance (specifically, characterization and QA programs at WIPP. In response to such concerns, releases from human intrusion waste generator sites through EPA believes it is useful to explain and scenarios) and concluded that the waste inspections and record reviews. clarify the general process of waste loading scheme would not affect In summary, EPA finds that DOE is in characterization as required by § 194.24, releases. The DOE incorporated the compliance with § 194.24, and that and to describe the activities EPA assumption of random waste loading in LANL has demonstrated compliance expects to monitor for future waste its performance and compliance with §§ 194.24(c)(3) through (5) for characterization. First, § 194.24(a) assessments (pursuant to §§ 194.32 and legacy debris waste and may therefore requires DOE to describe the chemical, 194.54, respectively). ship TRU waste for disposal at the WIPP radiological, and physical composition The EPA determined that, because the (as such shipments relate solely to of the wastes to be emplaced in the DOE had assumed random waste compliance with EPA’s disposal WIPP. Second, DOE must conduct an loading, a final waste loading plan was regulations; other applicable analysis that substantiates that: (1) all unnecessary. The EPA determined that, requirements or regulations still may characteristics of the wastes which may in the PA, DOE accurately modeled need to be fulfilled before disposal may influence containment in the repository random placement of waste in the commence). The EPA’s final have been identified and assessed disposal system. Since EPA concurred determination of compliance is limited (§ 194.24(b)(1)); (2) all components of with DOE that a final waste loading plan to the EPA’s decision is limited to the the wastes which influence such waste was unnecessary, DOE does not have to legacy debris waste that can be characteristics have been identified and further comply with § 194.24(f), characterized using the systems and assessed (§ 194.24(b)(2)); and (3) any requiring DOE to conform with the processes audited by DOE, inspected by decision not to consider a waste waste loading conditions, if any, used in EPA, and found to be adequately characteristic or component on the basis the PA and compliance assessment. implemented at LANL. It is important to that it will not significantly influence Therefore, EPA finds that DOE complies note that EPA’s LANL approval does not containment of the waste. with §§ 194.24(d) and (f). imply that DOE’s internal certification (§ 194.24(b)(3)) Third, for each waste Section 194.24(e) prohibits DOE from processes can substitute for EPA’s component identified as being emplacing waste in the WIPP if its approval of waste generator sites or significant, DOE is to specify a ‘‘limiting disposal would cause the waste processes used to characterize waste value’’ of the total inventory of such component limits to be exceeded. stream(s)—including QA measures, use waste components to be emplaced in the Section 194.24(g) requires DOE to of process knowledge, and the system of repository. (§ 194.24(c)) Fourth, DOE demonstrate that the total inventory controls (other than LANL’s legacy must demonstrate that, for the total emplaced in the WIPP will not exceed debris waste approved in today’s inventory of waste proposed to be limitations on TRU waste described in action). The EPA will inspect the emplaced in the disposal system, the the WIPP LWA. Specifically, the WIPP individual certification process for each WIPP will comply with the numeric LWA defines limits for: surface dose waste generator site and for one or more requirements of §§ 194.34 and 194.55 rate for remote-handled (‘‘RH’’) TRU waste stream(s). (For further information for the upper and lower limiting values waste, total amount (in curies) of RH– on EPA’s approval process, see § 194.8, of the identified waste components. TRU waste, and total capacity (by ‘‘Approval Process for Waste Shipment (§ 194.24(c)(1)) Fifth, DOE must identify volume) of TRU waste to be disposed. from Waste Generator Sites for Disposal and describe the methods used to (WIPP LWA, Section (7)(a)) In order to at the WIPP.’’) quantify the limits of waste meet the §§ 194.24(e) and (g) limits, The DOE may not ship other waste components. (§ 194.24(c)(2)) DOE intends to rely on the TRU QAPP, streams for emplacement at the WIPP At this point, § 194.24 imposes WAC, and a two-phase system of until EPA determines that (1) DOE has requirements that shift the focus from controls for waste characterization—pre- provided adequate information on how information on, and assessment of, the shipment (at waste generator sites) and process knowledge will be incorporated total waste inventory to procedures for 27392 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations characterization of the waste at standard operating procedures, the drum and possibly the entire waste individual waste generator sites and preliminary and final safety analysis stream is reclassified, and a higher accurate assessment of the waste reports and technical safety percentage of future drums will be inventory. First, DOE must show that requirements, waste packaging logs, site required to undergo visual examination. the AK used to quantify the waste databases, information from site Representativeness of containers components at the waste generator sites personnel, standard industry selected for visual examination will be will conform with QA requirements of information, previous analytical data validated by reviewing documents that § 194.22. Then, to ensure that the relevant to the waste stream, material show that true random samples were generator sites ship only waste that safety data sheets or other packaging collected. Repackaged retrievably stored conforms with the waste component information, sampling and analysis data waste may be handled as newly limits, a system of controls must be from comparable or surrogate waste generated waste, with the Summary implemented that tracks and measures streams, and laboratory notebooks that Category Group confirmed by using the waste components destined for the detail the research processes and raw visual examination instead of WIPP. This system of controls must also materials used in experiments. radiography. Retrievably stored waste comply with the QA requirements of The fundamental objective of EPA’s will be assayed using Non Destructive § 194.22. review of DOE’s waste characterization Assay (‘‘NDA’’) 35, and will undergo The approval process for site-specific at waste generator sites is to ensure that headspace-gas sampling and analysis for waste characterization controls and QA the proposed system of controls can volatile organic compound programs includes a Federal Register quantify and track both the concentrations.36 notice, public comment period, and on- radionuclides and the four waste Sixty-five percent of all WIPP waste is site EPA audits or inspections to component limits identified as to-be-generated TRU waste. To-be- evaluate implementation. (See important for the repository generated waste characterization will Condition 2, Condition 3, and § 194.8.) performance. Because DOE’s defense begin with verification that processes Prior to an EPA audit or inspection, EPA missions varied at the sites, the waste generating the waste have operated expects to receive certain documents generated and the methods to within established written procedures. from DOE. To determine that the characterize waste vary accordingly. Waste containers will be classified into procedures used to characterize waste These variations in practices and waste streams using acceptable (e.g., measuring and testing, sample methods result in the need to review knowledge. Hazardous and radioactive control, equipment assessments) are two general areas: (1) AK packages and constituents in to-be-generated wastes based on good technical practices, and (2) the system of controls, including will be documented and verified at the the personnel are qualified to perform measurement methods and tracking time of generation to provide acceptable the task, EPA expects to receive the procedures. Therefore, EPA finds that it knowledge for the waste stream. following general documents which is important to clarify what is entailed Verifying that the physical form of the conform with the requirements of by both general areas. waste (Summary Category Group) § 194.22: Site-Specific Quality Thirty-five percent of WIPP waste is corresponds to the physical form of the Assurance Program Plan (‘‘QAPP’’) and currently classified as ‘‘retrievably assigned waste stream is accomplished a report or reports from CAO’s QA stored waste,’’ which is TRU waste by visual examination during packaging organization that verifies the generated after the 1970’s but before the of the waste into the drums. This establishment and implementation of implementation of the TRU Waste process consists of operator the Nuclear Quality Assurance Characterization Quality Assurance confirmation that the waste is assigned requirements identified in § 194.22. Program Plan (‘‘QAPP’’). Retrievably to a waste stream that has the correct Likewise, DOE will provide technical stored waste containers will be Summary Category Group for the waste documents prior to an audit or classified into waste streams using being packaged into the drums. If inspection to verify the methods for acceptable knowledge.34 All retrievably confirmation cannot be made, corrective characterizing, quantifying, and tracking stored waste containers will be actions will be taken. A second waste. Such technical documents will examined using radiography or visual operator, who is equally trained to the include information on the use of both examination to confirm the physical requirements of the WAC and TRU process knowledge and measurement waste form (or ‘‘Summary Category Waste Characterization QAPP, will methods for waste characterization. Group’’), to verify the absence of provide additional verification by First, for measurement equipment such prohibited items, and to determine the reviewing the contents of the waste as NDA, NDE, and VE, DOE may waste characterization techniques to be provide information on measuring and used. To confirm the results of 35 All waste containers will undergo NDA testing, equipment assessments, sample radiography, a statistically selected techniques to allow an item to be tested without altering its physical or chemical form. NDA control, data documentation, and number of the Contact-Handled techniques approved for use on WIPP containers software control. For AK, DOE may Transuranic waste container population can be classified as active or passive. Passive NDA provide the AK package which provides will be visually examined by opening methods measure spontaneously emitted radiations information on the areas and buildings the containers to inspect waste contents produced through radioactive decay of isotopes inside the waste containers. Active NDA methods from which the waste stream was to verify the radiography results. If measure radiations produced by artificially generated, the waste stream volume and visual examination results for a drum generated reactions in waste material. time period of generation, the waste conflict with the results of radiography, 36 Results of head-space gas sampling and generating process described for each chemical analyses are compared with acceptable building, the process flow diagrams, and 34 AK is used by DOE to (1) delineate waste knowledge determinations to assess the accuracy of the material inputs or other information streams to facilitate further characterization; (2) acceptable knowledge. Additional analysis of head- identify radionuclide content as a basis for further space gas for volatile organic compounds, and that identifies the chemical and radioassay (‘‘NDA’’) determinations, and identify additional use of NDA, radiography, and other radionuclide content of the waste the combustible and metal content to determine the characterization methods may be employed to stream and the physical waste form. In radionuclide content as a basis for radiography and/ further characterize waste to meet regulations that addition, the following supplemental or visual examination (‘‘NDE/VE’’); and (3) make apply to the hazardous (but not necessarily hazardous waste determinations for wastes radioactive) portions of the WIPP waste. The information may be provided for AK regulated under the Resource Conservation and requirements for hazardous waste are enforced by records: process design documents, Recovery Act. the State of New Mexico. Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27393 container to ensure correct reporting. If on each TRU waste container. The bar- make predictions of the future state of the second operator cannot provide coded identification number is noted society, science, languages, or other concurrence, corrective actions will be and checked against the WWIS. The characteristics of mankind. However, taken. To-be-generated waste will not WWIS maintains waste container the Agency does believe that established undergo radiography, as the waste will receipt and emplacement information. scientific methods can make plausible be identified by visual examination Third, waste shipment irregularities or predictions regarding the future state of during packaging. All to-be-generated discrepancies are identified and geologic, hydrogeologic, and climatic waste containers will undergo resolved. If there are discrepancies, the conditions. Therefore, § 194.25 focuses headspace-gas analysis for volatile generator site is contacted for the PA and compliance assessments on organic compound and their resolution. Finally, WIPP personnel the more predictable significant features concentrations, and NDA for compare the container identification of disposal system performance, instead radioisotopes and their activities. number with a list of those approved for of allowing unbounded speculation on Acceptable knowledge, visual disposal at the WIPP. Waste shipment all developments over the 10,000-year examination during packing, NDA and approval or rejection for disposal at the regulatory time frame. headspace-gas sampling and analysis WIPP is the outcome of Phase II. (For The EPA proposed to find DOE in are used to further characterize further information on the system of compliance with the requirements of homogeneous solids, soils/gravel, and controls, see Docket A–93–02, Item V– § 194.25 because the future state debris waste. In addition, newly B–2, CARD 24, Section 24.H.2.) assumptions that DOE made and generated streams of such wastes will be In summary, all waste sent to WIPP documented in the CCA were inclusive randomly sampled a minimum of once will be appropriately and thoroughly of all relevant elements of the PA and per year and analyzed for total volatile characterized. First, the acceptable compliance assessments and were and semi-volatile organic compounds knowledge provides essential waste consistent with the requirements of and metals. content information that later § 194.25. (62 FR 58816–7) The Agency A system of controls is used to determines the waste categories. The AK reviewed the future state assumptions confirm that the total amount of each process undergoes quality assurance DOE made about hydrogeologic and waste component that will be emplaced checks to confirm good technical geologic characteristics and found that in the disposal system does not exceed practices and qualified personnel. Then, DOE accurately characterized, screened, the upper limiting value or fall below the measurement techniques (NDA, and modeled the potential changes from the lower limiting value for the NDE, VE) confirm the AK data, and current conditions. For climatic component. The system of controls for further define the content and limits of changes, EPA found DOE’s approach to WIPP waste has two phases for DOE’s the waste. Further confirmation of the be conservative and consistent with the internal process. Phase I entails Waste accuracy of the waste characterization is compliance criteria, since DOE Stream Screening and Verification, provided by the extensive tracking examined the worst-case scenario of which will occur before waste is system. Again, quality assurance checks increased precipitation at the WIPP shipped to the WIPP, and is a three-step are applied to the tracking and rather than the potential effects of global process. First, an initial audit of the site measurement controls. The waste warming, which could be beneficial to will be conducted by DOE’s Carlsbad characterization process, if the WIPP. (§ 194.25(b)(3)) The EPA Area Office as part its audit program implemented accordingly, provides found that DOE’s incorporation of these before the WIPP could begin the process complete and thorough characterization changes into the PA was adequate. of accepting waste from a site. The audit of the waste. The DOE has committed to Finally, EPA found that the CCA’s provides on-site verification of implement this process. No waste approach to dealing with uncertainty, characterization procedures, data generator site will be allowed to ship including use of conservative package preparation and recordkeeping. proposed waste streams to the WIPP assumptions to compensate for Second, the generator site personnel until the waste characterization process uncertainty, are consistent with the perform the waste characterization data detailed above is met at that generator features, events, and processes list, package completeness/accuracy review site for the given waste stream(s). screening arguments, and model and either accept or reject the data. descriptions. Third, if the data are accepted, the site 3. Future State Assumptions (§ 194.25) The EPA received no public waste characterization data are Section 194.25 stipulates that comments on this topic beyond those transferred manually or electronically performance assessments (‘‘PA’’) and addressed in the proposal, and so finds via the WWIS to the WIPP. At the WIPP, compliance assessments ‘‘shall assume DOE in compliance with the screening includes verification that all that characteristics of the future remain requirements of § 194.25. For further of the required elements of a waste what they are at the time the information concerning EPA’s characterization data package are compliance application is prepared, evaluation of compliance with § 194.25, present and that the data meet provided that such characteristics are see CARD 25. (Docket A–93–02, Item V– acceptance criteria required for not related to hydrogeologic, geologic or B–2) For additional information on the compliance. Waste stream approval or climatic conditions.’’ Section 194.25 features, events, and processes included rejection to ship to the WIPP is the also requires DOE to provide in the PA and compliance assessments, outcome of Phase I. documentation of the effects of potential see CARD 32 (Docket A–93–02, Item V– Phase II includes examination of a changes of hydrogeologic, geological, B–2) and the preamble discussion of waste shipment after it has arrived at and climatic conditions on the disposal performance assessment issues (Section the WIPP, and is a three-step process. system over the regulatory time frame. VIII.B). For additional information on First, upon receipt of a waste shipment, The purpose of the future state both geologic and hydrogeologic the WIPP personnel determine manifest assumptions is to avoid unverifiable and conditions of the WIPP, see the completeness and sign the manifest unbounded speculation about possible preamble discussion of § 194.14. before the driver may depart. Second, future states of society, science, WIPP personnel determine waste languages, or other characteristics of 4. Expert Judgment (§ 194.26) shipment completeness by checking the mankind. The Agency has found no The requirements of 40 CFR 194.26 bar-coded identification number found acceptable methodology that could apply to expert judgment elicitation. 27394 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

Expert judgment is typically used to size distribution parameter. (Docket A– expert judgment was consistent with elicit two types of information: 93–02, Item II–I–27) EPA’s use of the term ‘‘expert numerical values for parameters The waste particle size parameter is judgment’’ in the compliance criteria, (variables) that are measurable only by important in performance assessments namely a formal, highly structured experiments that cannot be conducted because the distribution of waste elicitation of expert opinion. (Response due to limitations of time, money, and particle diameters affects the quantity of to Comments for 40 CFR Part 194, physical situation; and essentially radioactive materials released in Docket A–92–56, Item V–C–1, p. 8–4) unknowable information, such as which spallings from inadvertent human However, EPA agrees that the CCA features should be incorporated into intrusion. Because particle diameters initially did not contain adequate passive institutional controls to deter are uncertain and cannot be estimated information to ascertain whether a large human intrusion into the repository. (61 either directly from available data or number of the input parameters had FR 5228) Quality assurance from data collection or experimentation, been properly derived. The DOE requirements (specifically the waste particle size parameter had to subsequently provided additional § 194.22(a)(2)(v)) must be applied to any be based on an elicitation of expert information, and substantially improved expert judgment to verify that the judgment. the quality of the records at the SNL procedures for conducting and The DOE conducted the expert Records Center, which enabled EPA to documenting the expert elicitation have judgment elicitation on May 5–9, 1997. confirm that all but one of the been followed. The results of the expert elicitation parameters were adequately supported. The requirements of 40 CFR Part 194 consisted of a model for predicting In regard to the use of professional prohibit expert judgment from being waste particle size distribution as a judgement in the development of input used in place of experimental data, function of the processes occurring parameters, the compliance criteria in unless DOE can justify that the within the repository, as predicted by § 194.26 do not provide for derivation of necessary experiments cannot be the PA. The DOE completed a final input parameters through ‘‘professional conducted. Expert judgment may report entitled, ‘‘Expert Elicitation on judgement.’’ Input parameters used in WIPP Waste Particle Size substitute for experimental data only in the PA are to be derived from data Distributions(s) During the 10,000-Year those instances in which limitations of collection, experimentation, or expert Regulatory Post-closure Period.’’ time, resources, or physical setting elicitation. The Agency, however, (Docket A–93–02, Item II–I–34) The preclude the successful or timely recognizes that raw data resulting from particle size distribution derived from collection of data. data collection or experimentation may the expert elicitation was incorporated require ‘‘professional judgment’’ in the The CCA did not identify any formal in the PA verification test (‘‘PAVT’’) development of input parameters. expert elicitation activities. During the calculations. Professional scientific judgment may be Agency’s review of performance The EPA’s review of DOE’s used to interpolate, extrapolate, assessment (‘‘PA’’) parameters, EPA compliance with the requirements of interpret, and apply data to develop found inadequate explanation and § 194.26 principally focused on the parameter values but cannot substitute information for 149 parameters that conduct of the elicitation process, since for data. (Expert judgment may DOE claimed had been derived using § 194.26 sets specific criteria for the substitute for data, but only when professional judgment. The compliance performance of an expert judgement information cannot reasonably be criteria do not provide for utilization of elicitation. The EPA observed DOE’s obtained through data collection or ‘‘professional judgement.’’ Input elicitation process and conducted an experimentation.) The applicability of parameters are to be derived from data audit of the documentation prepared in § 194.26 does not extend to professional collection, experimentation, or expert support of DOE’s compliance with scientific judgment used in such elicitation. The EPA requested that DOE § 194.26. The scope of the audit covered circumstances. (Docket A–92–56, Item provide additional information on the all aspects of the expert judgment V–C–1, p. 8–5) derivation of the 149 parameters. elicitation process, including: panel Based on its review of documentation (Docket A–93–02, Items II–I–17, II–I–25, meetings, management and team developed by DOE and its contractors, and II–I–27) procedures, curricula vitae of panel the results of EPA’s audit, and The DOE responded to EPA’s requests members, background documents, and consideration of public comments, EPA by adding information to and improving presentation materials. The EPA also concludes that DOE complied with the the quality of the records stored in the assessed compliance with the quality requirements of § 194.26 in conducting Sandia National Laboratory (‘‘SNL’’) assurance requirements of the required expert elicitation. For Records Center in order to enhance the § 194.22(a)(2)(v). The EPA found that further information on EPA’s evaluation traceability of parameter values. The the documentation was appropriate, that of compliance with § 194.26, see CARD EPA deemed the documentation the panel members were appropriately 26. (Docket A–93–02, Item V–B–2) provided by DOE adequate to qualified, and that the results of the demonstrate proper derivation of all but elicitation were used consistent with the 5. Peer Review (§ 194.27) one of the ‘‘professional judgment’’ stated purpose; EPA, therefore, Section 194.27 requires DOE to parameters—the waste particle size proposed to find DOE in compliance conduct peer review evaluations related distribution parameter. For a with § 194.26. (62 FR 58817–18) to conceptual models, waste comprehensive discussion of the Comments on EPA’s proposed characterization analyses, and a technical review of PA parameters, see decision for § 194.26 related to two comparative study of engineered the preamble discussion of performance main issues: (1) Commenters questioned barriers. A peer review involves an assessment, CARD 23 (Section 12.0), DOE’s statement that it did not conduct independent group of experts who are and EPA’s ‘‘Parameter Report’’ and any expert judgement activities in convened to determine whether ‘‘Parameter Justification Report.’’ developing the CCA; and (2) technical work was performed (Docket A–93–02, Items V–B–2, V–B– commenters questioned the use or role appropriately and in keeping with the 12, V–B–14) The EPA required DOE to of ‘‘professional judgement’’ in the intended purpose. The required peer use the process of expert elicitation to development of input parameters used reviews must be performed in develop the value for the waste particle in the CCA. The DOE’s understanding of accordance with the Nuclear Regulatory Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27395

Commission’s NUREG–1297, ‘‘Peer the first 100 years after disposal (i.e., distinguishes between pre-and post- Review for High-Level Nuclear Waste ranching, farming, hunting, scientific closure monitoring because the Repositories,’’ which establishes activities, utilities and transportation, monitoring techniques that may be used guidelines for the conduct of a peer ground water pumping, surface to access the repository during review exercise. Section 194.27 also excavation, potash exploration, operations (pre-closure) and after the requires DOE to document in the hydrocarbon exploration, construction, repository has been backfilled and compliance application any additional and hostile or illegal activities) and sealed (post-closure) are different. peer reviews beyond those explicitly examined the assumptions made by Monitoring is intended to provide required. DOE to justify the assertion that AICs information about the repository that The EPA proposed to find DOE in will be completely effective for 100 may affect the predictions made about compliance with the requirements of years. The DOE stated in the CCA that the PA or containment of waste. The § 194.27 because EPA’s independent the proposed AICs will be maintained EPA proposed that DOE was in audit established that DOE had for 100 years, and that regular compliance with this requirement. (62 conducted and documented the surveillance could be expected to detect FR 58827) required peer reviews in a manner a drilling operation in a prohibited area compatible with NUREG–1297. The that is set up in defiance or ignorance Public comments on EPA’s proposed Agency also proposed that DOE of posted warnings. decision stated that the monitoring plan adequately documented additional peer The EPA received public comments presented by DOE does not comply with reviews in the CCA. The EPA received on its proposed certification decision certain hazardous waste (Resource no public comments on this topic stating that it was unreasonable to Conservation and Recovery Act) and beyond those addressed in the proposal assume that AICs could be completely Nuclear Regulatory Commission (62 FR 58818), and so finds DOE in effective for 100 years. While EPA (‘‘NRC’’) requirements. However, the compliance with the requirements of recognizes that 100 percent monitoring techniques and parameters § 194.27. For further information effectiveness of AICs over 100 years suggested by commenters are not concerning EPA’s evaluation of cannot be established with certainty, the required by § 194.42, which requires compliance with § 194.27, see CARD 27. proposed AICs are fully within DOE’s only that the post-closure monitoring (Docket A–93–02, Item V–B–2) present capability to implement and plan be complementary to certain may be expected to be enforceable for a applicable hazardous waste monitoring D. Assurance Requirements period of 100 years. Therefore, EPA requirements. The purpose of this 1. Active Institutional Controls found it reasonable for DOE to assume language is to eliminate potential (§ 194.41) credit in the PA for 100 years. The EPA overlap with hazardous waste found the assumptions regarding Section 194.41 implements the active monitoring requirements while ensuring longevity and efficacy of the proposed that monitoring will be conducted even institutional controls (‘‘AICs’’) AICs to be acceptable based on the fact assurance requirement. The disposal if not required by the applicable that the types of inadvertent intrusion hazardous waste regulations. (Response regulations define AICs as ‘‘controlling which AICs are designed to obviate are access to a disposal site by any means to Comments for 40 CFR Part 194, not casual activities, but require Docket A–92–56, Item V–C–1, p. 14–7) other than passive institutional controls, extensive resources, lengthy procedures performing maintenance operations or for obtaining legal permission, and One commenter stated that DOE remedial actions at a site, controlling or substantial time to set up at the site should monitor additional parameters cleaning up releases from a site, or before beginning. and perform remote monitoring to monitoring parameters related to Contributions from AICs in the PA are prolong the length of time that data is disposal system performance.’’ (40 CFR considered as a reduction in the rate of gathered. The EPA determined that 191.12) Section 194.41 requires AICs to human intrusion. The EPA reviewed the monitoring the additional parameters be maintained for as long a period of CCA and the parameter inputs to the PA would provide no significant benefit time as is practicable after disposal; and determined that DOE did not because these parameters were not however, contributions from AICs for assume credit for the effectiveness of identified as significant to the reducing the rate of human intrusion in active institutional controls for more containment of waste or to verifying the PA may not be considered for more than 100 years after disposal. The EPA predictions made about the repository. than 100 years after disposal. found DOE’s assumptions to be The EPA also determined that The DOE proposed to: construct a sufficient to justify DOE’s assertion that additional remote monitoring of the fence and roadway around the surface AICs will completely prevent human panel rooms would neither provide footprint of the repository; post warning intrusion for 100 years after closure. significant information on the signs; conduct routine patrols and Because DOE adequately described the performance of the repository nor verify surveillance; and repair and/or replace proposed AICs and the basis for their predictions about its performance. physical barriers as needed. The DOE assumed effectiveness and did not also identified other measures that assume in the PA that AICs would be The plans in the CCA addressed both function as AICs, such as DOE’s effective for more than 100 years, EPA pre-closure and post-closure monitoring prevention of resource exploration at finds DOE in compliance with § 194.41. and included the information required the WIPP and DOE’s construction of For further information on EPA’s by the compliance criteria. Therefore, long-term site markers. The DOE will evaluation of compliance for § 194.41, EPA finds that DOE is in compliance maintain the proposed AICs for at least refer to CARD 41. (Docket A–93–02, with the requirements of § 194.42. 100 years after closure of the WIPP, and Item V–B–2) Under its authority at § 194.21, EPA the WIPP PA assumed that AICs would intends to conduct inspections of DOE’s prevent human intrusion for that period. 2. Monitoring (§ 194.42) implementation of the monitoring plans The EPA reviewed the proposed AICs Section 194.42 requires DOE to that DOE has set forth. For further in connection with the types of monitor the disposal system to detect information on EPA’s evaluation of activities that may be expected to occur deviations from expected performance. compliance for § 194.42, see CARD 42. in the vicinity of the WIPP site during The monitoring requirement (Docket A–93–02, Item V–B–2) 27396 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

3. Passive Institutional Controls sufficient to prevent drilling or other sees no cause to reverse its decision to (§ 194.43) intrusions into the WIPP over 10,000 deny DOE’s request for PICs credit The compliance criteria at § 194.43 years. The EPA has never asserted that under § 194.43(c). However, EPA’s final require a description of passive PICs, as an assurance measure, could or decision today applies only to the credit institutional controls (‘‘PICs’’) that will must be sufficient to prevent human proposal in the CCA and should not be be implemented at the WIPP. The EPA intrusion into a site entirely or for a interpreted as a judgment on the use of defined PICs in the disposal regulations specified period (such as 10,000 years). PICs credit in performance assessments as markers, public records and archives, In fact, the WIPP compliance criteria generally. In the future, DOE may government ownership of and prohibit DOE from assuming that PICs present to EPA additional information restrictions on land use at a site, and can completely eliminate the likelihood derived from an expert elicitation of of human intrusion. (§ 194.43(c)) DOE’s PICs credit. Any future PICs credit any other means of preserving design incorporates features that will proposals will be considered in the knowledge of a site. (40 CFR 191.12) serve to promote the endurance and context of a modification rulemaking, PICs are intended to deter unintentional comprehensibility of PICs over time, and will be subject to public intrusions into a disposal system by such as: redundant markers, highly examination and comment. people who otherwise might not be durable materials with low intrinsic aware of the presence of radioactive 4. Engineered Barriers (§ 194.44) value, messages in multiple languages, waste at the site. and record storage in multiple locations. Section 194.44 requires DOE to Section 194.43 requires DOE to: (1) Also, the CCA clearly discusses the conduct a study of available options for identify the controlled area with manner in which DOE accounted in the engineered barriers at the WIPP and markers designed, fabricated, and design for possible, realistic failures. submit this study and evidence of its emplaced to be as permanent as The Agency believes that the existence use with the compliance application. practicable; (2) place records in local of site-specific markers and records, Consistent with the assurance State, Federal, and international designed to be durable over long periods requirement found at 40 CFR 191.14, archives and land record systems likely of time, will greatly improve the DOE must analyze the performance of to be consulted by individuals in search chances that future generations will the complete disposal system, and any of resources; and (3) employ other PICs retain knowledge of the hazard posed by engineered barrier(s) that DOE intended to indicate the location and waste stored at the WIPP. ultimately implements at the WIPP must dangers of the waste. In accordance with The EPA proposed to deny DOE’s be considered in the PA and EPA’s § 194.43(b), DOE also must indicate the request under § 194.43(c) that the subsequent evaluation. Based on the period of time that PICs are expected to likelihood of human intrusion into the comparative study that constitutes endure and be understood by potential WIPP during the first 700 years after Appendix EBS of the CCA, DOE intruders. Finally, DOE is permitted to closure be reduced by 99 percent based proposed magnesium oxide (MgO) propose a credit for PICs in the PA, as on the anticipated effectiveness of PICs. backfill as an engineered barrier and explained in § 194.43(c). This credit The EPA denied the credit because DOE proposed to emplace bags of MgO must be based on the proposed did not use an expert judgment between and around waste containers in effectiveness of PICs over time, and elicitation to derive the credit, as the repository. The EPA proposed to would take the form of reduced explicitly envisioned by the Agency. find DOE in compliance with § 194.44 likelihood in the PA of human intrusion The EPA expected that an expert because DOE conducted and over several hundred years. The judgment elicitation that makes use of documented the required study in a compliance criteria prohibit DOE from the best available information and manner consistent with the WIPP assuming that PICs could entirely expertise would be used to account for compliance criteria and proposed to eliminate the likelihood of future the considerable uncertainties implement an engineered barrier to human intrusion into the WIPP. associated with a prediction of the delay the movement of water or The EPA proposed that DOE complied ability of PICs to prevent human radionuclides. (62 FR 58829) with § 194.43(a) and (b) because the intrusion hundreds of years into the Public comments on the proposal measures proposed in the CCA are future. Since the WIPP is located in an stated that the waste should be treated comprehensive, practicable, and likely area of resource exploitation, the before being placed in the repository. to endure and be understood for long uncertainty was not sufficiently Commenters stated that treatment of periods of time. The EPA also proposed reflected in the near 100 percent credit waste could serve to provide additional a condition that DOE submit additional proposed in the CCA. confidence in the safety of the disposal information concerning the schedule for The Agency received comments both system beyond that demonstrated by the completing PICs, the fabrication of supporting and refuting this decision. performance assessment, based on the granite markers, and commitments by Comments supporting EPA’s proposed assumption that waste treatment would various recipients to accept WIPP decision tended to reflect the position reduce the potential effects of a records. (62 FR 58827–29) The EPA did that any PICs credit would be too repository breach. Commenters not receive any comments disputing this uncertain for use in the PA. In therefore urged EPA to encourage DOE decision, and so finds DOE in opposition to EPA’s decision, comments to treat the waste in order to add compliance with § 194.43(a) and (b). stated that EPA drew improper additional assurance in the predicted However, DOE must fulfill Condition 4 conclusions about DOE’s use of expert performance of the WIPP. of Appendix A to 40 CFR Part 194 no judgment and treatment of uncertainty. Section 194.44 of the compliance later than the final recertification These comments requested that EPA criteria requires DOE to perform a application. For further information on reverse its denial of PICs credit, or at comparison of the benefits and EPA’s evaluation of compliance with least consider future credit proposals, detriments of waste treatment options § 194.43, see CARD 43. (Docket A–93– but did not identify why EPA’s (referred to as ‘‘engineered barriers’’ by 02, Item V–B–2) conclusions were incorrect other than to EPA and as ‘‘engineered alternatives’’ by Some commenters expressed the reiterate positions taken in the CCA that DOE). DOE’s evaluation incorporated concern that PICs in general, and DOE’s were explicitly assessed by EPA in the such treatment methods as vitrification plan in particular, would not be proposal. (62 FR 58828) Therefore, EPA and shredding. Based on this Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27397 evaluation, DOE selected the use of the different barriers on the performance modeling of solubility and chemical MgO as an engineered barrier. The EPA of the repository. There was no attempt conditions in the repository, see CARD determined that MgO will be an to determine the absolute effect of the 23—Models and Computer Codes. effective barrier, based on DOE’s barriers on the performance of the (Docket A–93–02, Item V–B–2) scientific evaluation of the proposed repository since the objective of the 5. Consideration of the Presence of barrier’s ability to prevent or study (in accordance with the WIPP Resources (§ 194.45) substantially delay the movement of compliance criteria) was only to provide radionuclides toward the accessible DOE with information for use in the Section 194.45 implements the environment. selection or rejection of additional assurance requirement that the disposal Section 194.44 does not require engineered barriers. (Docket A–93–02, system be sited so that the benefits of specific engineered barriers or the Item V–B–2, CARD 44, Section 44.C.4) the natural barriers of the disposal implementation of more than one It was not necessary for DOE to show system will compensate for any engineered barrier. Since DOE will the absolute effect of each barrier on the increased probability of disruptions to employ the use of a barrier as required WIPP’s performance in the face of a the disposal system resulting from by this section, and since the specific human intrusion scenario such exploration and development of existing performance assessment results showed as air drilling. Rather, it was sufficient resources. (61 FR 5232) In issuing the compliance with the containment for DOE to consider the relative ability WIPP compliance criteria, EPA requirements with the use of this of barriers to prevent or delay determined that the performance barrier, EPA does not consider it radionuclide migration in the event of assessment (‘‘PA’’) is the appropriate necessary to require DOE to treat waste human intrusion. tool to weigh the advantages and prior to emplacement. However, EPA Other comments expressed concern disadvantages of the WIPP site because agrees that waste treatment or additional that the ‘‘containment’’ and ‘‘assurance’’ the PA demonstrates whether potential barriers may further enhance the requirements were not kept separate, as human intrusion will cause containment ability of the WIPP. In the was intended by EPA’s disposal unacceptably high releases of future, if DOE were to select a new standards. The separation of the radioactive material from the disposal treatment option (such as vitrification) requirements is valid only to the extent system. Comments on § 194.45 for the that differs significantly from the option that engineered barriers may be used to proposed certification decision did not in the most recent compliance meet the containment requirements, but address the question of compliance with application, DOE must inform EPA prior must be used to meet the assurance this requirement but instead focused on to making such a change. requirements. The effects of all the criterion itself, stating that it was (§ 194.4(b)(3)(i) and (vi)) The EPA will engineered barriers employed at the inconsistent with the original basis for evaluate the information provided by WIPP must be considered in the assurance requirements to be DOE and determine if the certification performance assessments. Excluding qualitative in nature. The EPA believes warrants modification. such barriers from consideration would that the presence of resources Other commenters expressed concern result in inaccurate modeling of the requirement is reasonable because the that DOE failed to consider alternatives disposal system, which is defined in performance assessment must account to the proposed 55-gallon steel waste § 191.12(a) to include engineered for the increased potential for human drums that could reduce releases or the barriers. (Response to Comments for 40 intrusion into the disposal system due formation of gas in the repository due to CFR Part 194, Docket A–92–56, Item V– to the presence of known resources, the degradation of carbon. Commenters C–1, pp. 16–10, 16–13) Although not based on historical rates of drilling and further stated that DOE failed to required to comply with § 194.44, DOE mining in the vicinity of the WIPP. consider adequately how engineered and others performed calculations (Docket A–92–56, Item V–C–1, p. 17–1) barriers could reduce releases from four showing that the WIPP can comply with In any case, it is beyond the scope of the human intrusion scenarios: fluid the containment requirements with or certification rulemaking to injection, air drilling, stuck pipe, and without the use of MgO as an fundamentally re-examine or change the direct brine release. engineered barrier. (Docket A–93–02, disposal regulations or compliance The EPA recognized that gas Items IV–D–12 and IV–G–7) criteria as they relate to the presence of production from waste drum The EPA finds that DOE complies resources. degradation was a relevant issue and so with § 194.44. The EPA found that DOE Because the PA incorporated human included consideration of ‘‘improved conducted the requisite analysis of intrusion scenarios and met EPA’s waste containers’’ in the list of factors engineered barriers and selected an release limits in accordance with the for DOE to consider when evaluating engineered barrier designed to prevent WIPP compliance criteria, EPA engineered barriers. (40 CFR 194.44(b)) or substantially delay the movement of determines that DOE has demonstrated The DOE did, in fact, consider various water or radionuclides toward the compliance with § 194.45. For aspects of waste packages in the accessible environment. The DOE discussion of comments on human engineered barrier study. Appendix A of provided sufficient documentation to intrusion scenarios, results, and other Appendix EBS (p. A–10) states that the show that MgO can effectively reduce aspects of the PA, refer to Section B ‘‘improved waste container’’ options actinide solubility in the disposal (‘‘Performance Assessment: Modeling scored low in a qualitative assessment system. The DOE proposed to emplace and Containment Requirements’’) of this because of their minimal ability to a large amount of MgO around waste preamble. For further information on improve conditions with respect to drums in order to provide an additional EPA’s evaluation of compliance for waste solubility and shear strength. As factor of safety and thus account for § 194.45, refer to CARD 45. (Docket A– explained in CARD 44 (Docket A–93– uncertainties in the geochemical 93–02, Item V–B–2) 02, Item V–B–2), DOE also examined the conditions that would affect CO2 effects of engineered barriers on the generation and MgO reactions. For 6. Removal of Waste (§ 194.46) long-term performance of the WIPP further information on EPA’s evaluation Section 194.46 requires DOE to using the Design Analysis Model of compliance for § 194.44, see CARD provide documentation that the removal (‘‘DAM’’), which provided a relative 44. (Docket A–93–02, Item V–B–2) For of waste from the disposal system is comparison of the potential benefits of further information regarding the PA feasible for a reasonable period of time 27398 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations after disposal. In the proposed radionuclide releases from the WIPP interconnections. A USDW is defined at certification decision on WIPP, EPA would be greatest. The EPA required 40 CFR 191.22 as ‘‘an aquifer or its proposed that DOE was in compliance that the CCA identify the maximum portion that supplies a public water with this requirement. annual committed effective dose and the system, or contains a sufficient quantity Public comments on EPA’s proposed location where it occurs, and explain of ground water to do so and (i) decision expressed concern that there how DOE arrived at those results. currently supplies drinking water for would be no way to remove the waste In DOE’s analysis, an individual human consumption or (ii) contains once the WIPP repository is sealed. The receives the highest dose if one assumes fewer than 10,000 mg per liter of total technology used to dispose of the waste that the individual takes drinking water dissolved solids.’’ is substantially the same as the directly from the Salado Formation at The DOE identified three potential technology that would be used to the subsurface boundary of the WIPP USDWs near the WIPP—the Culebra remove it. This technology may area. The DOE assumed that an Member of the Rustler Formation, the reasonably be expected to remain individual would receive the maximum Dewey Lake Red Beds, and the Santa available for at least 100 years after the estimated dose regardless of location on Rosa Sandstone of the Dockum Group— repository is sealed. Public comments the surface and calculated the resultant despite incomplete data showing that also stated that EPA and DOE should doses accordingly. EPA found this they meet the regulatory definition of a identify the limitations of DOE’s approach to be conservative and USDW. The DOE did not analyze removal of waste plan. In Appendix proposed that DOE complied with underground interconnections among WRAC of the CCA, DOE acknowledges § 194.51. The Agency received no public these water bodies, instead assuming the expense and hazard of removing the comments on this topic beyond those conservatively that people would draw waste from the repository. The purpose addressed in the proposal (62 FR water directly from the Salado of the requirement at § 194.46 is to 58831), and so finds DOE in compliance Formation, bypassing other USDWs demonstrate that the removal of waste with the requirements of § 194.51. closer to the surface and thus resulting remains possible, not necessarily simply Section 194.52 requires DOE to in greater exposure. or inexpensive, for a reasonable period consider in compliance assessments all The EPA proposed that DOE complied of time after disposal. (50 FR 38082) potential exposure pathways for with § 194.53 because DOE adequately The DOE demonstrated that it is radioactive contaminants from the considered potential USDWs near the possible to remove waste from the WIPP. The DOE must assume that an WIPP. The Agency received a few repository for a reasonable period of individual consumes two liters per day public comments that raised questions time after disposal. Therefore, EPA of drinking water from any underground about DOE’s approach to evaluating determines that DOE is in compliance source of drinking water outside the USDWs. For example, some commenters with § 194.46. For further information WIPP area. questioned DOE’s assertion that USDWs on EPA’s evaluation of compliance with The DOE considered the following such as Laguna Grande de la Sal would § 194.46, see CARD 46. (Docket A–93– pathways: an individual draws drinking not be contaminated if the WIPP is left 02, Item V–B–2) water directly from the Salado undisturbed. In fact, the compliance Formation; an individual ingests plants assessments assumed that water in the E. Individual and Ground-water irrigated with contaminated water or Salado Formation constituted a Protection Requirements (§§ 194.51–55) milk and beef from cattle whose stock hypothetical USDW that would provide Sections 194.51 through 194.55 of the pond contained contaminated water drinking water after being diluted. compliance criteria implement the from the Salado; and an individual Radionuclide concentrations would be individual protection requirements of inhales dust from soil irrigated with expected to be greatest in the Salado at 40 CFR 191.15 and the ground-water contaminated water from the Salado. the subsurface boundary of the WIPP, protection requirements of Subpart C of Intended to result in the maximum since the disposal system is located in 40 CFR Part 191. Assessment of the dose, DOE’s assumption that water is that geologic formation. Thus, by likelihood that the WIPP will meet the ingested directly from the Salado demonstrating that EPA’s drinking individual dose limits and radionuclide actually is so conservative as to be water standards would be met where concentration limits for ground water is unrealistic, since Salado water is highly radioactive contamination would be conducted through a process known as saline and would have to be greatly greatest, DOE also showed that other, compliance assessment. Compliance diluted in order to function as drinking more distant potential aquifers also assessment uses methods similar to or irrigation water. would comply. This conservative those of the PA (for the containment The EPA proposed that DOE complied approach compensates for substantial requirements) but is required to address with § 194.52 because DOE considered uncertainties that would otherwise be only undisturbed performance of the all potential exposure pathways and involved in the calculation of disposal system. That is, compliance assumed that an individual consumes radionuclide transport to potential assessment does not include human two liters of Salado water a day, USDWs. intrusion scenarios (i.e., drilling or following dilution. The Agency received Even using an analysis that was mining for resources). Compliance no public comments on this topic designed to maximize radionuclide assessment can be considered a beyond those addressed in the proposal releases, DOE showed that the WIPP ‘‘subset’’ of performance assessment, (62 FR 58831), and so finds DOE in will comply with EPA’s limits for since it considers only natural compliance with the requirements of radionuclides in ground water by a wide (undisturbed) conditions and past or § 194.52. For further information margin. The EPA therefore finds DOE in near-future human activities (such as concerning EPA’s evaluation of compliance with § 194.53. For further existing boreholes), but does not include compliance for §§ 194.51 and 194.52, information concerning EPA’s the long-term future human activities see CARD 51/52. (Docket A–93–02, Item evaluation of compliance with § 194.53, that are addressed in the PA. V–B–2) see CARD 53. (Docket A–93–02, Item V– Section 194.51 requires DOE to Section 194.53 requires DOE to B–2) assume in compliance assessments that consider in compliance assessments Sections 194.54 and 194.55 relate to an individual resides at the point on the underground sources of drinking water the scope and results of compliance surface where the dose from (‘‘USDWs’’) near the WIPP and their assessments conducted to determine Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27399 compliance with the individual dose public land laws. The WIPP LWA For the reasons discussed above, EPA and ground-water protection transferred jurisdiction of the land to concluded in its proposed rule that the requirements. The EPA found that DOE the Secretary of Energy explicitly for the Secretary of Energy does not need to appropriately evaluated and screened use of constructing, operating, and acquire Federal Oil and Gas Leases No. out natural features, processes, and conducting other authorized activities NMNM 02953 and No. NMNM 02953C. events related to undisturbed related to the WIPP. The WIPP LWA (62 FR 58836) A number of comments performance, and proposed to find DOE prohibits all surface or subsurface on the proposed rule suggested that in compliance with § 194.54. (62 FR mining or oil or gas production is DOE conducted inadequate performance 58832) The Agency received no specific prohibited at all times on or under the assessment analyses on drilling comments on this decision. Comments land withdrawal area. (WIPP LWA, activities occurring prior to or soon after on issues that could affect predictions of section 4(b)(5)(A)) However, section disposal in the vicinity of the WIPP, but undisturbed performance, such as site 4(b)(5)(B) states that existing rights only one commenter took issue directly characterization or ground-water under two oil and gas leases (Numbers with EPA’s decision to not require the modeling, are discussed separately in NMNM 02953 and 02953C) (referred to Secretary of Energy to acquire the this preamble and did not necessitate as ‘‘the section 4(b)(5)(B) leases’’) shall Section 4(b)(5)(B) leases. This changes to compliance assessments. not be affected unless the Administrator commenter questioned the impact of (See ‘‘Geologic Scenarios and Disposal determines, after consultation with DOE drilling activities by lease holders. System Characteristics’’ under the and the Department of the Interior, that The DOE’s analysis of drilling for the Performance Assessment sections of this the acquisition of such leases by DOE is performance assessment indicated that preamble.) The EPA therefore finds that required to comply with EPA’s final wells drilled into the controlled area, DOE complies with § 194.54. For further disposal regulations. but away from the waste disposal room information on EPA’s evaluation of Before DOE can emplace waste in the and panels, will not adversely affect the compliance with § 194.54, see CARD 54. WIPP, DOE must acquire the leases, disposal system’s capability to contain (Docket A–93–02, Item V–B–2) unless EPA determines that such radionuclides. A slant-drilled borehole The EPA found that compliance acquisition is not required. (WIPP LWA, from outside the Land Withdrawal Area, assessments conducted by DOE section 7(b)(2)) This determination is into the section 4(b)(5)(B) lease area at appropriately documented uncertainty, separate and apart from the WIPP LWA least 6000 feet below the surface, would documented probability distributions requirement for EPA to conduct the be at least 2400 meters (8000) feet away for uncertain parameters, randomly certification decision by notice-and- from the WIPP disposal rooms and sampled across the distributions, and comment rulemaking. (WIPP LWA, would thus have an insignificant effect generated and displayed a sufficient section 8(d)). Nonetheless, the Agency on releases from the disposal system or number of estimates of radiation doses chose to address this matter as part of compliance with the disposal and ground-water concentrations. the certification process because the regulations. The EPA finds that Further, the resulting estimates of determination of whether potential potential activities at the section radiation doses and radionuclide drilling on the leases could possibly 4(b)(5)(B) leases will not cause the WIPP concentrations in ground water (and affect the integrity of the WIPP is closely to violate the disposal regulations. (For independent calculations by EPA) were related to similar determinations that more information on drilling scenarios, well below the limits in § 191.15 and must be made to determine compliance see the preamble discussions related to Subpart C of 40 CFR Part 191. In its with the disposal regulations and WIPP performance assessment.) Therefore, proposal, the Agency found that DOE is compliance criteria. (See §§ 194.32(c), EPA determines that it is not necessary in compliance with the requirements of 194.54(b)) for the Secretary of Energy to acquire § 194.55, and received no comments As discussed in the proposed the Federal Oil and Gas Leases No. disputing this decision, which is certification decision, EPA examined NMNM 02953 and No. NMNM 02953C. therefore finalized. For further DOE’s analysis of a number of potential information on EPA’s evaluation of activities in the life cycle of a well- X. Why and How Does EPA Regulate compliance for § 194.55, see CARD 55. drilling, fluid injection (for both the WIPP? (Docket A–93–02, Item V–B–2) waterflooding and brine disposal), and The WIPP Land Withdrawal Act is the abandonment—that could affect the statute that provides EPA the authority IX. Does DOE Need to Buy Existing Oil WIPP disposal system. The Agency to regulate the WIPP. The EPA’s and Gas Leases Near the WIPP? agreed with DOE that the effects of obligations and the limitations on EPA’s The EPA finds that DOE does not drilling a borehole would be highly regulatory authority under that law are need to acquire existing oil and gas localized, due to well casing procedures discussed below. leases in the vicinity of the WIPP in and borehole plugging practices. The A. The WIPP Land Withdrawal Act order to comply with EPA’s disposal EPA found that the effects of fluid regulations. These existing leases, and injection can also be expected to be The EPA’s oversight of the WIPP EPA’s need to evaluate their effects on localized, due to underground injection facility is governed by the WIPP Land the WIPP, are addressed by the 1992 control requirements. Finally, even Withdrawal Act (‘‘LWA’’), passed WIPP Land Withdrawal Act (‘‘LWA’’) abandoned boreholes would have little initially by Congress in 1992 and which provides for EPA’s regulatory consequence on waste panels more than amended in 1996. (Prior to the passage authority at the WIPP.37 (See Section X a meter away. Because the closest of the WIPP LWA in 1992, DOE was of this preamble, entitled ‘‘Why and possible approach of a borehole drilled self-regulating with respect to the WIPP; How Does EPA Regulate the WIPP,’’ for from the section 4(b)(5)(B) leases is over that is, DOE was responsible for more information on the WIPP LWA.) 2400 meters (8000 feet) from the WIPP determining whether its own facility The 1992 WIPP LWA withdrew the waste disposal rooms, EPA determined complies with applicable regulations for geographic area containing the WIPP that such a borehole would have an radioactive waste disposal.) The WIPP facility from all forms of entry, insignificant effect on releases from the LWA delegates to EPA three main tasks, appropriation, and disposal under disposal system (and in turn, on to be completed sequentially, for compliance with the disposal reaching a compliance certification 37 Pub. L. 102–579, sections 4(b)(5) and 7(b)(2). regulations). (62 FR 58835–58836) decision. First, EPA must finalize 27400 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations general regulations which apply to all to ensure the safety of the WIPP as a demonstrated compliance with the sites—except Yucca Mountain—for the permanent disposal facility. The disposal regulations and WIPP disposal of highly radioactive waste.38 Agency’s primary responsibility, compliance criteria, and are therefore These regulations, located at Subparts B described in section 8 of the WIPP outside the scope of this rulemaking. and C of 40 CFR Part 191 (‘‘disposal LWA, is to determine whether the WIPP Finally, the hazards of transporting regulations’’), were published in the facility will comply with EPA’s disposal radioactive waste from storage sites to Federal Register in 1985 and 1993.39 regulations. Members of the public have the WIPP is of great concern to the Second, EPA must develop, by expressed, in written comments and in public. Transportation is entirely rulemaking, criteria to implement and oral testimony on the proposed rule, a outside EPA’s general authority for interpret the general radioactive waste desire for the Agency to oversee other regulating radioactive waste. Moreover, disposal regulations specifically for the aspects of the WIPP’s operation. In in the WIPP LWA, Congress did not WIPP. The EPA issued the WIPP response to such concerns, EPA must authorize any role for EPA to regulate compliance criteria, which are found at clarify that its authority to regulate DOE transportation. Instead, the WIPP LWA 40 CFR Part 194, in 1996.40 and the WIPP is limited by the WIPP reiterated that DOE must adhere to Third, EPA must review the LWA and other statutes which delineate transportation requirements enforced by information submitted by DOE and EPA’s authority to regulate radioactive the U.S. Nuclear Regulatory publish a certification decision.41 materials in general. The limitations on Commission and the U.S. Department of Today’s action constitutes EPA’s EPA’s authority necessarily limit the Transportation. (WIPP LWA, section 16) certification decision as required by scope of the present rulemaking. Because all transportation requirements section 8 of the WIPP LWA. A number of commenters suggested for the WIPP are established and Today’s action also addresses the that EPA should explore alternative enforced by other regulators, EPA does requirement at section 7(b)(2) that, methods of waste disposal, such as not address the issue further in today’s before DOE can emplace waste in the neutralizing radioactive elements, action. WIPP, DOE must acquire existing oil before proceeding with a certification The preamble section entitled, ‘‘What and gas leases near the WIPP unless decision. Others stated that the WIPP is EPA’s response to general comments EPA determines that such acquisition is should be opened immediately because received on the certification decision?’’ not required in order for DOE to comply underground burial of radioactive waste provides further discussion of general with the disposal regulations. The EPA is less hazardous than the current issues, including several related to the determines that acquisition of the leases strategy of above-ground storage. In the scope of EPA’s certification rulemaking. is not necessary. For further discussion WIPP LWA, Congress did not delegate C. Compliance With Other of this requirement, refer to the to EPA the authority to abandon or Environmental Laws and Regulations delay the WIPP because future preamble section entitled, ‘‘Does DOE The WIPP must comply with a need to buy existing oil and gas leases technologies might evolve and eliminate the need for the WIPP. Also, Congress number of other environmental and near the WIPP?’’ safety regulations in addition to EPA’s Besides requiring EPA to issue a did not delegate to EPA the authority to weigh the competing risks of leaving disposal regulations—including, for certification decision, the WIPP LWA example, the Solid Waste Disposal Act also requires the Agency to conduct radioactive waste stored above ground compared to disposal of waste in an and EPA’s environmental standards for periodic recertifications, if the facility is the management and storage of initially certified. Every five years, EPA underground repository. These considerations are outside the authority radioactive waste. Various regulatory must determine whether documentation of EPA as established in the WIPP LWA, agencies are responsible for overseeing submitted by DOE demonstrates that the and thus outside the scope of this the enforcement of these Federal laws. WIPP continues to be in compliance rulemaking. However, as technologies For example, the WIPP’s compliance with the disposal regulations.42 evolve over the operating period of the with EPA’s radioactive waste Recertifications are not conducted WIPP, DOE may incorporate them into management regulations, found at through rulemaking, and are not the facility design through a Subpart A of 40 CFR Part 191, is addressed by today’s action. However, modification or during the required addressed by an EPA guidance the WIPP compliance criteria address recertification process. The EPA will document which describes how EPA the process by which EPA intends to evaluate how any such changes in intends to implement Subpart A at the conduct recertifications, including design or activities at the WIPP may WIPP. (Copies of the WIPP Subpart A publishing public notices in the Federal affect compliance with the radioactive Guidance are available by calling the Register and providing a public waste disposal regulations. WIPP Information Line at 1–800–331– comment period. (§ 194.64) For further Some commenters requested that EPA WIPP or from EPA’s WIPP home page at information on recertification, refer to consider certain factors in making its www.epa/gov/radiation/wipp.) the preamble sections entitled, ‘‘EPA’s certification decision. These factors Enforcement of some parts of the Future Role at the WIPP’’ and ‘‘How include reviews by organizations other hazardous waste management will the public be involved in EPA’s than EPA, and the political or economic regulations has been delegated to the future WIPP activities?’’ motivations of interested parties. The State of New Mexico. The State’s B. Limits of EPA’s Regulatory Authority EPA’s certification decision must be authority for such actions as issuing a at the WIPP made by comparing the scope and hazardous waste operating permit for quality of relevant information to the the WIPP is in no way affected by EPA’s As discussed above, the WIPP LWA objective criteria of 40 CFR Part 194. certification decision. It is the conveys specific responsibilities on EPA Where relevant, the Agency has responsibility of the Secretary of Energy considered public comments which to report the WIPP’s compliance with all 38 WIPP LWA, section 8(b). support or refute technical positions applicable Federal laws pertaining to 39 50 FR 38066–38089 (September 19, 1985) and 43 58 FR 66398–66416 (December 20, 1993). taken by DOE. Emotional pleas and public health and the environment. 40 61 FR 5224–5245 (February 9, 1996). comments on the motives of interested Compliance with environmental or 41 WIPP LWA, section 8(d). parties are factors that are not relevant 42 WIPP LWA, section 8(f). to a determination of whether DOE has 43 WIPP LWA, sections 7(b)(3) and 9. Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27401 public health regulations other than The notice also announced a 120-day C. Public Hearings on Proposed Rule EPA’s disposal regulations and WIPP public comment period, requested Further information on the hearings compliance criteria is not addressed by public comment ‘‘on all aspects of the was provided in a Federal Register today’s action. CCA,’’ and stated EPA’s intent to hold notice published on December 5, 1997. public hearings in New Mexico. (62 FR 64334–64335) The Agency XI. How Has the Public Been Involved The EPA published a separate notice conducted hearings in three cities in in EPA’s WIPP Activities? in the Federal Register announcing New Mexico—Carlsbad, Albuquerque, Section 8(d)(2) of the WIPP LWA hearings to allow the public to address and Santa Fe—on January 5 through 9, requires that the Administrator’s all aspects of DOE’s certification 1998. The EPA took a number of steps certification decision be conducted by application. (62 FR 2988) Public to ensure that citizens were aware of the informal (or ‘‘notice-and-comment’’) hearings were held on February 19, 20 hearings and to accommodate requests rulemaking pursuant to Section 4 of the and 21, 1997, in Carlsbad, Albuquerque to testify before the EPA panel. For Administrative Procedure Act (‘‘APA’’). and Santa Fe, New Mexico, respectively. Notice-and-comment rulemaking under In addition to the public hearings, EPA example, EPA placed forty-six notices in the APA requires that an agency provide held three days of meetings in New newspapers across the State to advertise notice of a proposed rulemaking, an Mexico, on January 21, 22 and 23, 1997, the hearings and provided a manned, opportunity for the public to comment with the principal New Mexico toll-free telephone line for pre- on the proposed rule, and a general Stakeholders. Detailed summaries of registration. The Agency also allowed statement of the basis and purpose of these meeting were placed in Docket A– on-site registration, and extended the the final rule.44 93–02, Category II–E. hours of the hearings in both The WIPP compliance criteria, at The Agency received over 220 sets of Albuquerque and Santa Fe in order to Subpart D of 40 CFR Part 194, written and oral public comments in allow everyone present who wished to established a process of public response to the ANPR. The Agency testify the opportunity to do so. participation that exceeds the APA’s reviewed all public comments D. Additional Public Input on the basic requirements, and provides the submitted during the ANPR 120-day Proposed Rule public with the opportunity to comment period or presented at the participate in the regulatory process at preliminary meetings with stakeholders. In addition to the public hearings, the earliest opportunity. The WIPP The EPA provided responses to these EPA held two days of meetings in New compliance criteria contain provisions comments in the preamble to the Mexico, on December 10–11, 1997, with that require EPA to: publish an advance proposed certification as well as in the the principal New Mexico stakeholders, notice of proposed rulemaking compliance application review including the New Mexico Attorney (‘‘ANPR’’) in the Federal Register; allow documents (‘‘CARDs’’) for the proposed General’s Office, the New Mexico public comment on DOE’s compliance certification decision. The CARDs also Environmental Evaluation Group certification application (‘‘CCA’’) for at addressed late comments—and (‘‘EEG’’), Concerned Citizens for Nuclear least 120 days, prior to proposing a comments on the completeness of DOE’s Safety, Citizens for Alternatives to certification decision; hold public CCA—received after the close of the Radioactive Dumping, and Southwest hearings in New Mexico, if requested, public comment period (on March 17, Research and Information Center. on the CCA; provide a minimum of 120 1997) but before August 8, 1997. (62 FR Detailed summaries of these meetings days for public comment on EPA’s 27996–27998) All relevant public were placed in Docket A–93–02, Item proposed certification decision; hold comments, whether received in writing, IV–E–8. Additional meetings were also public hearings in New Mexico on or orally during the public hearings, held in January 1998 in New Mexico EPA’s proposal; produce a document were considered by the Agency as the and Washington, DC with the New summarizing the Agency’s proposed certification decision was Mexico EEG (IV–E–10 and IV–E–11) and consideration of public comments on developed. For further discussion of other stakeholders (IV–E–11). the proposal, and maintain EPA’s completeness determination and In response to concerns expressed in informational dockets in the State of other pre-proposal activities, see the meetings with stakeholders and in New Mexico to facilitate public access preamble to the proposed certification public hearings, EPA performed to the voluminous technical record, decision, 62 FR 58794–58796. additional analyses of air drilling (a specialized drilling method which including the CCA. The EPA has B. Proposed Certification Decision complied with each of these stakeholders raised as an issue which requirements. On October 30, 1997, EPA published could potentially affect the WIPP if it a Notice of Proposed Rulemaking in the occurred near the site). In light of the A. Public Involvement Prior to Proposed Federal Register, fulfilling the significant public interest in this issue, Rule requirements of the WIPP compliance EPA conducted its analysis and released The EPA received DOE’s CCA on criteria at § 194.62. (62 FR 58792– its report during the comment period on October 29, 1996. Copies of the CCA 58838) The notice announced the the proposed rule, in order to allow an and all the accompanying references Administrator’s proposed decision, opportunity for the public to comment submitted to EPA were placed in EPA’s pursuant to section 8(d)(1) of the WIPP on EPA’s technical analysis. The dockets in New Mexico and LWA, as amended, to issue a Agency published a Federal Register Washington, DC. On November 15, certification that the WIPP facility will notice of availability for the report and 1996, the Agency published in the comply with the disposal regulations, provided a 30-day public comment Federal Register (61 FR 58499) an and solicited comment on the proposal. period. (63 FR 3863; January 27, 1998) ANPR announcing that the CCA had The notice also marked the beginning of The report was placed in the public been received, and announcing the a 120-day public comment period on docket and also sent electronically to a Agency’s intent to conduct a rulemaking EPA’s proposed certification decision. number of interested stakeholders, to certify whether the WIPP facility will Finally, the notice announced that including the New Mexico Attorney comply with the disposal regulations. public hearings would be held in New General, the New Mexico Mexico during the public comment Environmental Evaluation Group, 44 5 U.S.C. 553. period. Citizens for Alternatives to Radioactive 27402 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations

Dumping, Concerned Citizens for room 1500 (first floor in Waterside Mall Rulemaking in the Federal Register. Nuclear Safety, and Southwest Research near the Washington Information This notice will announce EPA’s and Information Center. Center), U.S. Environmental Protection proposed action, describe the basis for Agency, 401 M Street, S.W., the decision, and provide the E. Final Certification Decision, Response Washington, D.C., 20460 (open from opportunity for public comment on the to Comments Document 8:00 a.m. to 4:00 p.m. on weekdays); 2) proposal. Documentation related to the Today’s notice of EPA’s final EPA’s docket in the Government decision will be made available to the certification decision pursuant to Publications Department of the public through EPA’s docket. Any final section 8(d)(1) of the WIPP LWA fulfills Zimmerman Library of the University of rule on modification or revocation will the requirement of the WIPP compliance New Mexico located in Albuquerque, also be published in the Federal criteria at § 194.63(a). Also in New Mexico, (open from 8:00 a.m. to Register. In addition, EPA will release a accordance with § 194.63(b), EPA is 9:00 p.m. on Monday through Thursday, document which summarizes and publishing a document, accompanying 8:00 a.m. to 5:00 p.m. on Friday, 9:00 responds to significant public comments today’s action and entitled ‘‘Response to a.m. to 5:00 p.m. on Saturday, and 1:00 received on its proposal. Comments,’’ which contains the p.m. to 9:00 p.m. on Sunday); 3) EPA’s The recertification process—EPA’s Agency’s response to all significant docket in the Fogelson Library of the periodic review of the WIPP’s continued comments received during the comment College of Santa Fe in Santa Fe, New compliance with the disposal period on the proposed certification Mexico, located at 1600 St. Michaels regulations and WIPP compliance decision. (Docket A–93–02, Item V–C–1) Drive (open from 8:00 a.m. to 12:00 criteria—will include many of the same (For further discussion of EPA’s midnight on Monday through Thursday, elements as notice-and-comment treatment of ANPR and other pre- 8:00 a.m. to 5:00 p.m. on Friday, 9:00 rulemaking. For example, EPA will proposal comments, refer to the a.m. to 5:00 p.m. on Saturday, 1:00 p.m. publish a Federal Register notice preamble to the proposed rule, 62 FR to 9:00 p.m. on Sunday); and 4) EPA’s announcing its intent to conduct such 58794–58796.) All comments received docket in the Municipal Library of an evaluation. The certification by EPA, whether written or oral, were Carlsbad, New Mexico, located at 101 S. application for recertification will be given equal consideration in developing Halegueno (open from 10:00 a.m. to 9:00 placed in the docket, and at least a 30- the final rule. All comments received by p.m. on Monday through Thursday, day period will be provided for the Agency were made available for 10:00 a.m. to 6:00 p.m. on Friday and submission of public comments. The public inspection through the public Saturday, and 1:00 p.m. to 5:00 p.m. on Agency’s decision on whether to docket. (Docket A–93–02, Categories IV– Sunday). As provided in 40 CFR Part 2, recertify the WIPP facility will again be D, IV–F, and IV–G) a reasonable fee may be charged for announced in a Federal Register notice. F. Dockets photocopying docket materials. (§ 194.64) Although not required by the APA, In accordance with 40 CFR 194.67, XII. How Will the Public be Involved in the WIPP LWA, or the WIPP compliance EPA maintains a public docket (Docket EPA’s Future WIPP Activities? criteria, EPA intends to place in the A–93–02) that contains all information The EPA’s regulatory role at the WIPP docket all inspection or audit reports used to support the Administrator’s does not end with its initial certification and annual reports by DOE on proposed and final decisions on decision. The Agency’s future WIPP conditions and activities at the WIPP. certification. The Agency established activities will include periodic The Agency also plans to docket and maintains the formal rulemaking recertifications, review of DOE reports information pertaining to the docket in Washington, D.C., as well as on activities at the WIPP, assessment of enforcement of certification conditions. informational dockets in three locations waste characterization and QA programs For the enforcement of Conditions 2 and in the State of New Mexico (Carlsbad, at waste generator sites, announced and 3 (regarding quality assurance (‘‘QA’’) Albuquerque, and Santa Fe). The docket unannounced inspections of the WIPP and waste characterization programs at consists of all relevant, significant and other facilities, and possibly waste generator sites), a number of information received to date from modification, revocation, or suspension additional steps will be taken. As outside parties and all significant of the certification for cause. These described in § 194.8 of the WIPP information considered by the activities are described above in the compliance criteria, before approving Administrator in reaching a certification preamble section entitled ‘‘EPA’s Future QA and waste characterization controls decision regarding whether the WIPP Role at the WIPP.’’ The EPA has at generator sites, EPA will publish a facility will comply with the disposal provided for public involvement in Federal Register notice announcing regulations. The EPA placed copies of these activities through rulemaking EPA inspections or audits. The requisite the CCA in Category II–G of the docket. procedures, Federal Register notices plans and other appropriate inspection The Agency placed supplementary and public comment periods, and by or audit documentation will be placed information received from DOE in making information available in its in the docket, and the public will be response to EPA requests in Categories public dockets. (See the preamble allowed the opportunity to submit II–G and II–I. sections entitled ‘‘Dockets’’ and ‘‘Where written comments. A comment period of The final certification decision and can I get more information about EPA’s at least 30 days will be provided. Thus, supporting documentation can be found WIPP activities?’’ for more information EPA’s decisions on whether to approve primarily in the following categories of regarding EPA’s rulemaking docket.) waste generator QA program plans and Docket A–93–02: Category V–A (final While a suspension may be initiated waste characterization controls’—and rule and preamble), Category V–B at the discretion of the Administrator in thus, to allow shipment of specific (Compliance Application Review order to promptly reverse or mitigate a waste streams for disposal at the Documents and Technical Support potential threat to public health, any WIPP’—will be made only after EPA has Documents), and Category V–C modification or revocation of the conducted an inspection or audit of the (Response to Comments document). certification will be conducted through waste generator site and after public The hours and locations of EPA’s rulemaking. (§§ 194.65–66) To modify comment has been solicited on the public information dockets are as or revoke the certification, EPA will first matter. The Agency’s decisions will be follows: Docket No. A–93–02, located in publish a Notice of Proposed conveyed by a letter from EPA to DOE. Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27403

A copy of the letter, as well as the to the public. (Instructions for obtaining action was submitted to OMB for results of any inspections or audits, will access to DOE documents can be found review. Changes made in response to be placed in EPA’s docket. at Docket A–93–02, Item V–B–1.) OMB suggestions or recommendations are documented in the public record. XIII. Where Can I Get More B. WIPP Information Line, Mailing List, Information About EPA’s WIPP and Internet Homepage B. Regulatory Flexibility Activities? For more general information and The Regulatory Flexibility Act The EPA’s docket functions as the updates on EPA’s WIPP activities, (‘‘RFA’’) generally requires an agency to official file for Agency rulemakings. The interested citizens may contact EPA’s conduct a regulatory flexibility analysis EPA places all information used to toll-free WIPP Information Line at 1– of any rule subject to notice and support its proposed and final decisions 800–331–WIPP. The hotline offers a comment rulemaking requirements in the docket, which is available for recorded message, in both English and unless the agency certifies that the rule review by the public. For the WIPP Spanish, about current EPA WIPP will not have a significant economic certification rulemaking, information is activities, upcoming meetings, and impact on a substantial number of small placed in Air Docket Number A–93–02. publications. Callers are also offered the entities. Small entities include small The official docket is located in option of joining EPA’s WIPP mailing businesses, small not-for-profit Washington, DC, and informational list. Periodic mailings, including a WIPP enterprises, and small governmental dockets are provided in three cities in Bulletin and fact sheets related to jurisdictions. This final rule will not New Mexico. (See the ‘‘Dockets’’ section specific EPA activities, are sent to have a significant impact on a of this preamble for more information members of the mailing list (currently substantial number of small entities on the location and hours of EPA’s numbering over 800). The WIPP internet because it sets forth requirements which WIPP dockets.) The contents of the homepage, at www.epa.gov/radiation/ apply only to Federal agencies. docket include technical information wipp, provides general information on Therefore, I certify that this action will received from outside parties and other EPA’s regulatory oversight of the WIPP. not have a significant economic impact information considered by EPA in Federal Register notices are also on a substantial number of small reaching a certification decision, as well announced on the homepage, and a entities. as the Agency’s rationale for its number of documents (ranging from C. Paperwork Reduction Act decision. The technical support outreach materials and hearings documents which describe the basis for transcripts to technical support The EPA has determined that this EPA’s certification decision are documents) are available to review or proposed rule contains no information discussed below; sources of more download. collection requirements as defined by general information on EPA’s WIPP the Paperwork Reduction Act (44 U.S.C. activities are also addressed. XIV. With What Regulatory and 3501 et seq). Administrative Requirements Must A. Technical Support Documents This Rulemaking Comply? D. Unfunded Mandates Reform Act For more specific information about Title II of the Unfunded Mandates A. Executive Order 12866 the basis for EPA’s certification Reform Act of 1995 (‘‘UMRA’’), Pub. L. decision, there are a number of Under Executive Order 12866, (58 FR 104–4, establishes requirements for technical support documents available. 51735; October 4, 1993), the Agency Federal agencies to assess the effects of The Compliance Application Review must determine whether the regulatory their regulatory actions on State, local Documents, or CARDs, contain the action is ‘‘significant’’ and therefore and tribal governments and the private detailed technical rationale for EPA’s subject to OMB review and the sector. Pursuant to Title II of the UMRA, certification decision. This document is requirements of the Executive Order. EPA has determined that this regulatory found at Docket A–93–02, Item V–B–2. The Order defines ‘‘significant action is not subject to the requirements The CARDs discuss DOE’s regulatory action’’ as one that is likely of sections 202 and 205, because this compliance with the individual to result in a rule that may: (1) have an action does not contain any ‘‘federal requirements of the WIPP compliance annual effect on the economy of $100 mandates’’ for State, local, or tribal criteria. Each CARD is a section in the million or more or adversely affect in a governments or for the private sector. document which is numbered according material way the economy, a sector of The rule implements requirements that to the section of 40 CFR Part 194 to the economy, productivity, competition, are specifically set forth by the Congress which it pertains. For example, CARD jobs, the environment, public health or in the Waste Isolation Pilot Plant Land 23 addresses § 194.23, ‘‘Models and safety, or State, local, or tribal Withdrawal Act (Pub. L. 102–579) and Computer Codes.’’ Each CARD: restates governments or communities; (2) create that apply only to Federal agencies. the specific requirement, identifies a serious inconsistency or otherwise relevant information expected in the interfere with an action taken or E. Executive Order 12898 CCA, explains EPA’s compliance review planned by another agency; (3) Pursuant to Executive Order 12898 criteria, summarizes DOE’s approach to materially alter the budgetary impact of (59 FR 7629, February 16, 1994), compliance, and describes EPA’s entitlements, grants, user fees, or loan entitled ‘‘Federal Actions to Address compliance review and decision. The programs or the rights and obligations of Environmental Justice in Minority CARDs also list additional EPA recipients thereof; or (4) raise novel Populations and Low-Income technical support documents and any legal or policy issues arising out of legal Populations,’’ the Agency has other references used by EPA in mandates, the President’s priorities, or considered environmental justice rendering its decision on compliance. the principles set forth in the Executive related issues with regard to the All technical support documents and Order. Pursuant to the terms of potential impacts of this action on the references are available in Docket A–93– Executive Order 12866, it has been environmental and health conditions in 02 with the exception of generally determined that this final rule is a low-income, minority, and native available references and those ‘‘significant regulatory action’’ because American communities. The EPA has documents already maintained by DOE it raises novel policy issues which arise complied with this mandate. The or its contractors in locations accessible from legal mandates. As such, this requirements specifically set forth by 27404 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations the Congress in the Waste Isolation Pilot affect the right or obligations of non- Atomic Energy Act of 1954, as amended, 42 Plant Land Withdrawal Act (Pub. L. agency parties. (5 U.S.C. 804(3)) The U.S.C. 2011–2296 and 10101–10270. 102–579), which prescribes EPA’s role EPA is not required to submit a rule 2. In § 194.2, a definition is added in at the WIPP, did not provide authority report regarding today’s action under alphabetical order to read as follows: for EPA to examine impacts in the section 801 because this is a rule of communities in which wastes are particular applicability. § 194.2 Definitions. produced, stored, and transported, and * * * * * Congress did not delegate to EPA the G. National Technology Transfer & Administrator’s authorized authority to consider alternative Advancement Act of 1995 representative means the director in locations for the WIPP. Section 12 of the National Technology charge of radiation programs at the The EPA involved minority and low- Transfer & Advancement Act of 1995 is Agency. income populations early in the intended to avoid ‘‘re-inventing the 3. Section 194.8 is added to subpart rulemaking process. In 1993 EPA wheel.’’ It aims to reduce the costs to A to read as follows: representatives met with New Mexico the private and public sectors by residents and government officials to requiring federal agencies to draw upon § 194.8 Approval Process for Waste Shipment from Waste Generator Sites for identify the key issues that concern any existing, suitable technical Disposal at the WIPP them, the types of information they standards used in commerce or wanted from EPA, and the best ways to industry. To comply with the Act, EPA (a) Quality Assurance Programs at communicate with different sectors of must consider and use ‘‘voluntary Waste Generator Sites. The Agency will the New Mexico public. The feedback consensus standards,’’ if available and determine compliance with provided by this group of citizens applicable, when implementing policies requirements for site-specific quality formed the basis for EPA’s WIPP and programs, unless doing so would be assurance programs as set forth below: (1) Upon submission by the communications and consultation plan. ‘‘inconsistent with applicable law or Department of a site-specific quality To help citizens, including a significant otherwise impractical.’’ The EPA has assurance program plan the Agency will Hispanic population in Carlsbad and the determined that this regulatory action is evaluate the plan to determine whether nearby Mescalero Indian Reservation, not subject to the requirements of it establishes the applicable Nuclear stay abreast of EPA’s WIPP-related National Technology Transfer & Quality Assurance (NQA) requirements activities, the Agency developed many Advancement Act of 1995 as this of § 194.22(a)(1) for the items and informational products and services. rulemaking is not setting any technical activities of §§ 194.22(a)(2)(i), The EPA translated into Spanish many standards. documents regarding WIPP, including 194.24(c)(3) and 194.24(c)(5). The educational materials and fact sheets H. Executive Order 13045—Children’s program plan and other documentation describing EPA’s WIPP oversight role Health Protection submitted by the Department will be and the radioactive waste disposal This final rule is not subject to E.O. placed in the dockets described in standards. The EPA also established a 13045, entitled ‘‘Protection of Children § 194.67. toll-free WIPP Information Line, from Environmental Health Risks and (2) The Agency will conduct a quality recorded in both English and Spanish, Safety Risks’’ (62 FR 19885, April 23, assurance audit or an inspection of a providing the latest information on 1997), because it does not involve Department quality assurance audit at upcoming public meetings, decisions on environmental health risks the relevant site for the purpose of publications, and other WIPP-related or safety risks that may verifying proper execution of the site- activities. The EPA also developed a disproportionately affect children. specific quality assurance program plan. vast mailing list, which includes many The Agency will publish a notice in the low-income, minority, and native List of Subjects in 40 CFR Part 194 Federal Register announcing a American groups, to systematically Environmental protection, scheduled inspection or audit. In that or provide interested parties with copies of Administrative practice and procedure, another notice, the Agency will also EPA’s public information documents Nuclear materials, Radionuclides, solicit public comment on the quality and other materials. Even after the final Plutonium, Radiation protection, assurance program plan and appropriate rule, EPA will continue its efforts Uranium, Transuranics, Waste treatment Department documentation described in toward open communication and and disposal. paragraph (a)(1) of this section. A public comment period of at least 30 days will outreach. Dated: May 13, 1998. be allowed. F. Small Business Regulatory Carol M. Browner, (3) The Agency’s written decision Enforcement Fairness Act of 1996 Administrator. regarding compliance with the requisite The Congressional Review Act, 5 For the reasons set out in the quality assurance requirements at a U.S.C. 801 et seq., as added by the Small preamble, 40 CFR Part 194 is amended waste generator site will be conveyed in Business Regulatory Enforcement as follows. a letter from the Administrator’s Fairness Act of 1996, generally provides authorized representative to the PART 194ÐCRITERIA FOR THE that before a rule may take effect, the Department. No such compliance CERTIFICATION AND RE- agency promulgating the rule must determination shall be granted until CERTIFICATION OF THE WASTE submit a rule report, which includes a after the end of the public comment ISOLATION PILOT PLANT'S copy of the rule, to each House of the period described in paragraph (a)(2) of COMPLIANCE WITH THE 40 CFR PART Congress and to the Comptroller General this section. A copy of the Agency’s 191 DISPOSAL REGULATIONS of the United States. Section 804, compliance determination letter will be however, exempts from section 801 the 1. The authority citation for part 194 placed in the public dockets in following types of rules: rules of is revised to read as follows: accordance with § 194.67. The results of particular applicability; rules relating to Authority: Pub. L. 102–579, 106 Stat. 4777, any inspections or audits conducted by agency management or personnel; and as amended by Pub. L. 104–201,110 Stat. the Agency to evaluate the quality rules of agency organization, procedure, 2422; Reorganization Plan No. 3 of 1970, 35 assurance programs described in or practice that do not substantially FR 15623, Oct. 6, 1970, 5 U.S.C. app. 1; paragraph (a)(1) of this section will also Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations 27405 be placed in the dockets described in programs described in paragraph (b)(1) determines that the site has established and § 194.67. of this section for one or more waste executed a quality assurance program, in (4) Subsequent to any positive streams from a waste generator site will accordance with §§ 194.22(a)(2)(i), determination of compliance as be conveyed in a letter from the 194.24(c)(3) and 194.24(c)(5) for waste described in paragraph (a)(3) of this characterization activities and assumptions. Administrator’s authorized The Agency will determine compliance of section, the Agency intends to conduct representative to the Department. No site-specific quality assurance programs at inspections, in accordance with such compliance determination shall be waste generator sites using the process set §§ 194.21 and 194.22(e), to confirm the granted until after the end of the public forth in § 194.8. continued compliance of the programs comment period described in paragraph Condition 3: § 194.24: Waste approved under paragraphs (a)(2) and (b)(2) of this section. A copy of the Characterization. The Secretary may allow (a)(3) of this section. The results of such Agency’s compliance determination shipment for disposal at the WIPP of legacy inspections will be made available to letter will be placed in the public debris waste at the Los Alamos National Laboratory (‘‘LANL’’) that can be the public through the Agency’s public dockets in accordance with § 194.67. dockets, as described in § 194.67. characterized using the systems and The results of any inspections or audits processes inspected by the Agency and (b) Waste Characterization Programs conducted by the Agency to evaluate the documented in Docket A–93–02, Item II–I– at Waste Generator Sites. The Agency plans described in paragraph (b)(1) of 70. The Secretary shall not allow shipment will determine compliance with the this section will also be placed in the of any waste from any additional LANL requirements for use of process dockets described in § 194.67. waste stream(s) or from any waste generator knowledge and a system of controls at (4) Subsequent to any positive site other than LANL for disposal at the WIPP waste generator sites as set forth below: determination of compliance as until the Agency has approved the processes (1) For each waste stream or group of described in paragraph (b)(3) of this for characterizing those waste streams for waste streams at a site, the Department shipment using the process set forth in section, the Agency intends to conduct § 194.8. must: inspections, in accordance with (i) Provide information on how Condition 4: § 194.43, Passive institutional §§ 194.21 and 194.24(h), to confirm the controls. process knowledge will be used for continued compliance of the programs waste characterization of the waste (a) Not later than the final recertification approved under paragraphs (b)(2) and application submitted prior to closure of the stream(s) proposed for disposal at the (b)(3) of this section. The results of such disposal system, the Department shall WIPP; and inspections will be made available to provide, to the Administrator or the (ii) Implement a system of controls at the public through the Agency’s public Administrator’s authorized representative: the site, in accordance with (1) a schedule for implementing passive § 194.24(c)(4), to confirm that the total dockets, as described in § 194.67. 4. Appendix A to Part 194 is added institutional controls that has been revised to amount of each waste component that show that markers will be fabricated and to read as follows: will be emplaced in the disposal system emplaced, and other measures will be will not exceed the upper limiting value Appendix A to Part 194—Certification implemented, as soon as possible following or fall below the lower limiting value of the Waste Isolation Pilot Plant’s closure of the WIPP. Such schedule should described in the introductory text of Compliance With the 40 CFR Part 191 describe how testing of any aspect of the conceptual design will be completed prior to paragraph (c) of § 194.24. The Disposal Regulations and the 40 CFR or soon after closure, and what changes to the implementation of such a system of Part 194 Compliance Criteria design of passive institutional controls may controls shall include a demonstration In accordance with the provisions of the be expected to result from such testing. that the site has procedures in place for WIPP Compliance Criteria of this part, the (2) documentation showing that the granite adding data to the WIPP Waste Agency finds that the Waste Isolation Pilot pieces for the proposed monuments and Information System (‘‘WWIS’’), and that Plant (‘‘WIPP’’) will comply with the information rooms described in Docket A– such information can be transmitted radioactive waste disposal regulations at part 93–02, Item II–G–1, and supplementary from that site to the WWIS database; 191, subparts B and C, of this chapter. information may be: quarried (cut and and a demonstration that measurement Therefore, pursuant to Section 8(d)(2) of the removed from the ground) without cracking due to tensile stresses from handling or techniques and control methods can be WIPP Land Withdrawal Act (‘‘WIPP LWA’’), as amended, the Administrator certifies that isostatic rebound; engraved on the scale implemented in accordance with the WIPP facility will comply with the required by the design; transported to the § 194.24(c)(4) for the waste stream(s) disposal regulations. In accordance with the site, given the weight and dimensions of the proposed for disposal at the WIPP. Agency’s authority under § 194.4(a), the granite pieces and the capacity of existing (2) The Agency will conduct an audit certification of compliance is subject to the rail cars and rail lines; loaded, unloaded, and or an inspection of a Department audit following conditions: erected without cracking based on the for the purpose of evaluating the use of Condition 1: § 194.14(b), Disposal system capacity of available equipment; and process knowledge and the design, panel closure system. The successfully joined. implementation of a system of controls Department shall implement the panel seal (3) documentation showing that archives and record centers will accept the documents for each waste stream or group of waste design designated as Option D in Docket A– 93–02, Item II–G–1 (October 29, 1996, identified and will maintain them in the streams at a waste generator site. The Compliance Certification Application manner identified in Docket A–93–02, Item Agency will announce a scheduled submitted to the Agency). The Option D II–G–1. inspection or audit by the Agency with design shall be implemented as described in (4) documentation showing that proposed a notice in the Federal Register. In that Appendix PCS of Docket A–93–02, Item II– recipients of WIPP information other than or another notice, the Agency will also G–1, with the exception that the Department archives and record centers will accept the solicit public comment on the relevant shall use Salado mass concrete (consistent information and make use of it in the manner waste characterization program plans with that proposed for the shaft seal system, indicated by the Department in Docket A– and Department documentation, which and as described in Appendix SEAL of 93–02, Item II–G–1 and supplementary Docket A–93–02, Item II–G–1) instead of information. will be placed in the dockets described fresh water concrete. (b) Upon receipt of the information in § 194.67. A public comment period of Condition 2: § 194.22: Quality Assurance. required under paragraph (a) of this at least 30 days will be allowed. The Secretary shall not allow any waste condition, the Agency will place such (3) The Agency’s written decision generator site other than the Los Alamos documentation in the public dockets regarding compliance with the National Laboratory to ship waste for identified in § 194.67. The Agency will requirements for waste characterization disposal at the WIPP until the Agency determine if a modification to the 27406 Federal Register / Vol. 63, No. 95 / Monday, May 18, 1998 / Rules and Regulations compliance certification in effect is necessary. Any such modification will be conducted in accordance with the requirements at §§ 194.65 and 194.66. [FR Doc. 98–13100 Filed 5–15–98; 8:45 am] BILLING CODE 6560±50±P