Revision I October 1979 U.S. NUCLEAR REGULATORY COMMISSION REGULATORY GUIDE OFFICE OF STANDARDS DEVELOPMENT
REGULATORY GUIDE 8.21
HEALTH PHYSICS SURVEYS FOR BYPRODUCT MATERIAL AT NRC-LICENSED PROCESSING AND MANUFACTURING PLANTS C. REGULATORY POSITION A. INTRODUCTION procedures in this guide are acceptable to Paragraph 20.201(b) of 10 CFR Part 20, "Standards for Methods and acceptable survey programs Protection Against Radiation," requires that each licensee the NRC staff for establishing as low as is reasonably achievable make or cause to be made such surveys as may be necessary in accordance with the Manufacturers licensed by the NRC for him to comply with the regulations in Part 20. As used (ALARA) philosophy. of developing and in Part 20, the term "survey" is defined as an evaluation of should have a health physics staff capable the radiation hazards incident to the production, use, re implementing survey programs as described below. lease, disposal, or presence of radioactive materials or other sources of radiation under a specific set of conditions. This 1. TYPES OF SURVEYS guide identifies the types and frequencies of surveys that are acceptable to the NRC staff for use in plants licensed by 1.1 General Description the NRC for processing byproduct material or manufactur 1 with §20.201 of 10 ing such material for distribution. Surveys performed in compliance CFR Part 20 should include those necessary to evaluate B. DISCUSSION external exposure to personnel, concentrations of airborne radioactive materials in the facility, surface contamination Surveys are considered to be part of a comprehensive levels, and radioactive effluents from the facility. Environ established by the licensee according mental monitoring of effluents is beyond the scope of this protection program 3 to the philosophy and principles of Regulatory Guide 8.10, guide . "Operating Philosophy for Maintaining Occupational Radia tion Exposures As Low As Is Reasonably Achievable." Prin Radiation protection programs should include the types ciples, methods, and instrumentation for carrying out radia of surveys discussed below.. tion and contamination surveys were developed early in the atomic energy program and have been discussed in reports 1.2 Surveys of External Radiation Exposure Levels in of the National Council on Radiation Protection and Mea Restricted Areas surement (NCRP) (Refs. 1-3), the International Atomic Energy Agency (IAEA) (Refs. 4-8), and the International Radiation safety personnel 4 should survey locations Commission on Radiological Protection (ICRP) (Ref. 9). where individuals may be exposed to radiation intensities The health physics literature contains abundant informa that might result in radiation doses in excess of 10 percent tion for use in establishing radiation survey programs and of the limits of paragraph 20.101(a) of 10 CFR Part 20 in selecting appropriate methods, procedures, and equipment any calendar quarter or where an individual is working with for their implementation (Refs. 3, 5, and 6). a source that could be used unshielded at any time to pro- * 0.5 mrad/h at 2 duce a gamma or beta dose rate exceeding Surveys are a necessary supplement to personnel moni 1 meter. toring, which measures individual radiation exposures with 0 devices worn by the workers (Refs. 3, 5, 6, 8, and 9). Lines indicate substantive changes from previous issue. 1 3However, the radiation safety program should include surveys or NRC-Uicensed processing and manufacturing plants are referred records that indicate control of the quantities of radioactive material to in this guide as "manufacturing plants." released in air and water to unrestricted areas, as required by 10 CFR 2 Part 20. The word "survey," often used synonymously with "surveil 4Reference to radiation safety staff or personnel in this guide is ance," "monitoring," or "area monitoring," is used in this guide not intended to indicate that such staff necessarily consists of more to connote the personal Inspection of various locations in a facil than one person designated as responsible for radiation safety. The ity using radioactive materials, with or without accompanying size and qualifications of the staff depend on the scope and idnd of measurements, to determine the effectiveness of measures to manufacturing activities involving radioactive materials. protect against radiation.
GUIDES Comments should be sent to the Secretary of the Commission. USNRC REGULATORY U.S. Nuclear Regulatory Commission Washington, D.C. 20555, Regulatory Guides are Issued to describe and make available to the Attention: Docketing and Service Branci. public methods acceptable to the NRC staff of implementing specific parts of the Commission's regulations, to delineate tech- The guides are issued in the following ten broad divisions: niques used by the staff In evaluating specific problems or postu ated accidents or to provide guidance to applicants. Regulato 1. Power Reactors 6. Products Guides are noi substitutes for regulations, and compliance with 2. Research and Test Reactors 7. Transportation from those set 3. Fuels and Materials Facilities 8. Occupational Health them is not required. Methods and solutions different Financial Review out In the guides will be acceptable If they, provide a basis for the 4. Environmental and Siting 9. Antitrust and findings requisite to the Issuance or continuance of a permit or 5. Materials and Plant Protection 10. General license by the Commission. Copies of Issued guides may be purchased at thecurrent Government in spe Comments and suggestions for improvements In these guides are Printing Office price. A subscription service for future guides encouraged at all times, and guides will be revised,. as appropriate, cific divisions Is available through the Government Printing Office. to accommodate comments and to reflect new information or Information on the subscription service and current GPO prices may experience. This guide was revised as a result of substantive com- be obtained by writing the U.S. Nuclear Regulatory Commission, ments received from the public and additional staff review. Washington, D.C. 20555, Attention: Publications Sales Manager. of the volume of air Preoperational, routine, and special surveys of these on the filter surface. Overestimates should be avoided by areas should be performed by the radiation protection staff that has passed through the filter accurate calibration of the flow rate and by pre as described in Section C.2 of this guide. Results of these means of or correcting for the loss of flow due to the accu surveys should be recorded as described in Section C.3. venting of material on the filter. In addition, workers should monitor themselves and their mulation own individual activities if they are exposed to external Breathing zone or general air sampling should be con radiation levels that could exceed any of the limits of para unless the results of con graph 20.101(a). These surveys by workers should consist ducted while work is in progress concentration of radio of periodic instrument surveys during work with radioactive tinuous sampling verify that the in the breathing zone is not likely to exceed materials. Workers should be properly trained to conduct active material 10 CFR Part 20, Appen such surveys. 25 percent of the values given in dix B, Table I, Column 1. The use of personal (lapel) continuous air sampling as long Surveys are not acceptable for routine compliance with samplers is acceptable for are adequate to detect 25 percent of the the personnel monitoring requirements of §20.202. How as airflow rates B. during the sam ever, in the event of accidental loss of personnel dosimetry appropriate values in Table I of Appendix sampling frequency, if not con data, e.g., as a result of losing the dosimeter or chemical pling period. The air selected for sampling should be or physical damage to the dosimeter, the best alternative tinuous, and the times of the manufacturing process involved means of estimating the exposure may be to use survey data based on the nature and the probability that airborne radioactive material will in conjunction with any fixed station dosimeters, doses this probability is difficult, received by co-workers, and appropriate occupancy fac be present. When assessing given in Section C.2 and tors. In such case, the estimate, including the survey data frequencies based on information Table 1 of this guide are acceptable. used, should be documented and retained indefinitely (see paragraph 20.401(c)(2)(ii)). Survey results supplement personnel monitoring, when it is required, and they should An air monitors may be needed to provide a warningsignal become be reviewed carefully by the Radiation Safety Officer in that the concentration of airborne radioactivity has radioactive conjunction with personnel monitoring records to identify unexpectedly high. For each room or area where an analysis potentially hazardous situations and to ensure that all per material is handled, the licensee should perform to determine whether an air monitor is necessary. Each anal sonnel are adequately monitored. 6 ysis should be kept available for inspection. An air moni it is 1.3 Measurements of Radioactive Material Concentrations tor should be provided if the analysis indicates that air monitor in Air likely that, in the absence of an appropriate alarm, accidental conditions could cause an intake of radio-I result from The radiation safety staff should perform measure active material exceeding the intake that would ments of radioactive material concentrations in air, at inhaling such material for 40 hours at the concentrations Part 20, Appendix B, Table I,Column 1.7 frequencies specified in Section C.2 of this guide, for areas specified in 10 CFR where radioactive materials are handled or processed in recognize that the principal function of unencapsulated form and when operations could expose Workers should to take immediate workers to the inhalation of quantities of radioactive mate an air monitor is to alert personnel exposure to the unex rial exceeding those specified in paragraph 20.103(b)(2). action to protect themselves from pected release of airborne radioactive material. Inhalation Special requirements for such monitoring may also be made during the time between the re a condition of the license. exposures are in progress lease of the radioactive material and the sounding of the effort should be made to Air samples collected should be representative of the air alarm. Thus, every reasonable this time period. In particular, the air inlet of the in the workers' breathing zone. However, when obtaining minimize near the potential source of air representative samples from the breathing zone is not prac monitor should be located radionuclides, preferably between the source and the ticable, the samples should be obtained from a location at borne use of long tubing or piping leading to the in which the radioactivity concentration in air is known to workers. The of the high probability of be greater than that of the workers' breathing zone. For let should be avoided because example, samples taken outside the breathing zone are alarm delay due to radionuclide deposition on the interior acceptable if the sampler head is located so that the concen tration of radioactive material in air at the location of the $The term "air monitor" as used here refers to a device providing sampler head is equal to or greater than the concentration an air or particle collection system, a radiometric measurement sys in the breathing zone. tem, a continuous recorder (when the monitor Is also to be used to | assess personnel exposures), a meter with preset alarm capability, and an audible-alarm system. the quantity of radioactive material When measuring 6Applicants should provide either the name of the manufacturer deposited on or in an air sample filter, the radiation safety and model number of the air monitor to be used, specifications forI staff should include appropriate corrections for alpha or the appropriate type of air monitor to be used, or a copy of the monitor is not required. beta absorption by the filter media and by material col analysis that verifies that an air lected on the filter whenever these corrections may change 7To determine the quantity of radioactive material associated results more than 10 percent. Filter media used for the col with this 40-hour exposure, multiply the concentation value 10 CFR Part 20 by 4.8 x lO ml. lection of alpha emitters should retain collected material specified in Appendix B to
8.21-2 When contamination levels in restricted areas can poten pipe. The dose to personnel may be walls of the tube or tially exceed 0.1 percent of the respective limits in line 2 setpoint for the reduced by selecting a low-activity-level of Table 2, the collection of smear samples should gener in false alarms that weaken alarm; however, this may result ally be preceded by a rapid overall survey with a portable, These alternatives the workers' confidence in the monitor. thin-window detector in order to: should be balanced to maximize safety. a. Ensure that gross contamination levels are not already by providing The dose to personnel may also be reduced for counting in sensitive equipment, or too high a high flow rate of air through the detection chamber orifice that is intended filter. A device such as a limiting b. Minimize the chance for inadvertent spread of con rate should not be used with to provide a constant flow tamination by the smear survey or other activities to be flow rate to a level in Ian air monitor when it reduces the performed in the meantime, and adequate for sufficient warning of an accidental release. It a high volume of air drawn is more important to maintain c. Determine which areas require greater attention in time of exposure be through the filter, thus reducing the smear testing. fore the alarm by using a higher flow rate, than to measure However, it is also important the concentration accurately. The instrument used should have a readout system with as and continuous releases be moni that routine intermittent short a time constant as appropriate for the type of radia tored. tion to be detected and should be equipped with earphones I or an external speaker system. 1.4 Surface Contamination Surveys A standardized method for smear testing of a relatively monitoring for radioactive contamination that Routine uniform area should be used to aid in comparing contami on surfaces of floors, walls, laboratory could be present nation at different times and places. A dry smear taken and equipment is a necessary part of the survey 2 furniture, from an area of about 100 cm is acceptable to indicate to control surface contamination may program. Failure levels of removable contamination. result in unnecessary external or internal exposure of per Although external radiation levels from sonnel to radiation. A diagram of each routinely surveyed area should may at times be hazardous, the radioactive contamination ordinarily be used for recording survey results. When appro is to avoid internal exposure resulting primary concern priate, the diagram may be supplemented by or replaced by of loose radioactive material by inhalation, from the intake a detailed list of items and equipment surveyed. This pro or skin absorption. Also of concern is limiting ingestion, cedure will provide radiation safety personnel with a meth to areas where it can be controlled and contamination od for identifying trends as well as satisfying regulatory contamination levels low enough that leaks or maintaining requirements for survey records. The surveyor will find it control equipment can be detected as early as failures in helpful to specify key locations on the survey diagram that practicable. are smear-tested at each survey, in addition to other areas to be smear-tested in particular surveys, and also to provide Removable Contamination 1.4.1 a space reminding the recorder to include: For the purpose of this guide, removable contamination . a. Contamination levels converted to radioactivity units fraction of the contamination present on a surface is that in terms of equivalent alpha, beta, or gamma emission per a smear test paper by rubbing that can be transferred to unit area, in units specified in 10 CFR Part 20, with moderate pressure. Considerable information is avail aid radiation protection personnel in the selection able to b. Make and model number of instruments used in the and use of instruments for performing surface contamina survey and in counting the smear samples or appropriate tion surveys appropriate to the radionuclides involved in reference to information in the same set of available rec 1-22). manufacturing plants (Refs. ords, and instruments used in surface contamination Methods c. Disintegration rate of each sample, surveys should be sufficiently sensitive to detect the nu Also, uniform methods for collect clides being monitored. d. Background count, ing and analyzing smear samples should be used over ex time in order to evaluate trends. Count tended periods of e. All counting times, and ing equipment used to analyze radioactive contamination should be properly calibrated and main on smear samples f. Name of the person making the evaluation and re be capable of detecting the radiation tained and should cording the results and date. from the smears. For example, smears containing low energy radiation emitters (e.g., H-3, C-14, 1-125) should be Provision should also be made on the diagram for recording with liquid scintillation or internal proportional analyzed an instrument check with an appropriate check or calibra sources should be counted counters. Check or calibration tion source. with each batch or daily workload of smear samples.
8.21-3 The surveys discussed above are regularly scheduled, the instructions in Regulatory Guide 8.15, "Acceptable conducted by radiation safety personnel, and recorded on Programs for Respiratory Protection." Section 20.103 of the survey diagrams. In addition, whenever the manufac 10 CFR Part 20 specifies monitoring requirements when turing process is such that excessive contamination could protection factors are assumed to be provided by the use of occur between surveys by radiation safety personnel, more respiratory protection devices. frequent, informal radiation surveys should be conducted by the radiation workers themselves; they need not be Potentially contaminated protective clothing recorded. For example, a contamination and equip survey can be ment should be surveyed, removed, and placed in suitable made by collecting a smear sample and holding it within a containers or lockers before the worker leaves the restricted few mm of (but not touching) a thin (less than 2 mg/cm 2 ) area. Since airborne radioactivity from contaminated end-window detector while the detector is in an area where protective clothing is likely to be produced by dislodging radiation levels are less than about 0.05 mrem/h. At these any absorbed radioactive particles during removal, fixed levels, any appreciable surface contamination can be de station monitors should also be available in clothing change tected by simply holding the detector in a fixed position areas to survey clothing before it is removed whenever and moving the smear sample close to and away from the clothing contamination levels may exceed 10 percent of the detector several times and noting the meter readings. This limits on line 4 of Table 2. In addition, suitable areas method may be used for the majority of radionuclides should be provided for surveying protective clothing and processed in manufacturing plants (excluding alpha and equipment before storing them for further use or for very low-energy beta emitters). decontamination and laundering.
Part 20 of 10 CFR does not specify limits for surface When protective clothing contamination levels exceed contamination. Each applicant should propose and justify preselected limits, workers should be instructed to take care what removable surface contamination limits will be allow to avoid dispersal of contamination and to report the situa able before decontamination will be performed in each tion to the Radiation Safety Office. A member of the radi work area. These limits should be based on the types of ation safety staff should then survey and supervise any nec work to be performed and the need to avoid transfer of essary decontamination or clothing disposal. The applicant significant amounts of contamination to unrestricted areas should propose and justify protective clothing contamina and to maintain exposures as low as is reasonably achieva tion limits considered adequate for each restricted area. ble (ALARA). The contamination limits for restricted areas The limits given on line 4 of Table 2 are the maximum that presented in Table 2 of this guide are the maximum that will be acceptable to the NRC staff. will be acceptable to the NRC staff. Limits established for a particular installation should generally be lower than Contamination levels observed and procedures followed those in Table 2 and should be ALARA for the particular for incidents requiring special surveys and decontamination operations involved. should be recorded. The record should include the names of persons surveyed, a description of prior work activities, 1.4.2 Fixed Contamination the probable causes, steps taken to reduce future incidence of contamination, times and dates, and the surveyor's sig For the purpose of this guide, fixed contamination nature. This information may be entered in a logbook. Indi is defined as radioactivity remaining on a surface after vidual worker surveys of themselves need not be recorded repeated decontamination attempts fail to significantly unless the limits on line 3 of Table 2 are exceeded. However, reduce the' contamination level. Since most detectors the radiation safety staff should maintain daily surveillance respond to both removable and fixed contamination, to ensure that the workers continue their own personal con limits should be based on total contamination. Total con tamination surveys. Results of radiation safety tamination surveillance surveys, using instruments suitable for the should be recorded. radionuclides involved, should be conducted at least quar terly and simultaneously with a removable contamination In restricted areas with little potential for surface con survey. The applicant may propose and justify what total tamination, personal clothing is often worn beneath protec contamination limits will be allowable for both restricted tive clothing. Such personal clothing should be surveyed by and in-plant unrestricted areas before decontamination will the wearer before he or she leaves the restricted area. (How be performed. The limits appearing on line 2 of Table 2, ever, this is neither practicable nor necessary for employees multiplied by a factor of 5, are the maximum that will be working with only submicrocurie quantities of tritium or acceptable to the NRC staff. Limits that are ALARA carbon-14.) When personal clothing contamination levels should be established and justified by each applicant. exceed preselected limits, workers should be instructed to report the situation to the Radiation Safety Office. A mem 1.5 Protective Clothing and Equipment Contamination ber of the radiation safety staff should then survey and Surveys supervise any necessary decontamination or clothing dis posal. The applicant may propose and justify personal cloth Individuals working in areas where a potential for skin ing (total) contamination limits. The limits given on line 3 or clothing contamination exists should be provided with of Table 2 are acceptable to the NRC staff and need not be suitable protective clothing. If respiratory protective equip justified by the applicant. Clothing contamination is assumed ment is needed to protect against inhalation of airborne to be removable but may be measured by a portable end radioactivity, the equipment should be used according to window detector as total contamination for survey purposes.
8.21-4 levels are ALARA or additional efforts do not significantly as those Records should be maintained in the same manner reduce contamination levels. The applicant may propose for protective clothing contamination. and justify total and removable contamination limits below which uncontrolled release of equipment is permitted. The in restricted For individuals whose work is conducted limits given for unrestricted areas on line I of Table 2 are levels, by areas with a potential for high surface contamination acceptable to the NRC staff and need not be justified complete clothing changes are normally provided. In this the applicant. case, personal clothing should be stored outside the restrict pro ed area. Surveys of personal clothing are not necessary, 1.8 Ingestion surveyed as vided the area in which the clothing is stored is the survey discussed in Section C.1.4 of this guide and Although it is highly unlikely that significant internal unrestrict near results are below the limits adopted for in-plant exposures will result from ingesting drinking water to surveying ed areas. Particular attention should be paid work areas (Ref. 4), any water fountains in areas where the hands or water is possible should the body, hair, bottoms of the shoes or feet, and contamination of the fountains before after removal of protective clothing and to washing be smear-tested regularly, and the water should be sampled donning personal clothing. and analyzed at least quarterly. Also, surveillance should be included in the radiation safety program to ensure that 1.6 Personal Surveys workers observe rules to prevent ingestion of radionuclides, e.g., rules pertaining to eating, drinking, or smoking in work restricted areas Individuals whose duties require work in areas or while wearing potentially contaminated clothing, is proba where radioactive contamination of body surfaces storing foods in work areas, or pipetting by mouth. after ble should also survey all exposed areas of the body or leaving showering and before donning personal clothing 1.9 Surveys of Packages Received and Packages Pre the restricted area. Workers should be required to report pared for Shipment Radia the detection of contamination on the body to the the tion Safety Office. Decontamination attempts, under External radiation surveys and smear tests of external or a medical direction of Radiation Safety Office personnel surfaces of packages received or packaged for shipment such attempts consultant, should be repeated until (a) should be carried out near the receiving or packaging point cease to effect significant reductions or (b) such attempts radiation exposures and inadvertent 8 to avoid unwarranted threaten to damage the skin. When decontamination contamination of personnel or the facility. When many further con attempts are terminated, there should be no packages of a kind known to be generally free of contami exceed pre cern if the residual contamination does not nation are received, smear testing of a suitable random sam would no longer selected levels since the contamination ple should be considered in cases where smear testing of a levels should present a significant ingestion hazard. Such large number of packages could increase external exposure If residual con be proposed and justified by the applicant. of personnel. Surveys and required labeling must comply affected indi tamination exceeds the selected limits, the with regulatory requirements (see §§20.205, 32.19, and should be vidual should be released but periodic surveys 32.70 through 32.74 of 10 CFR) and with specific license The resulting made until the limits are no longer exceeded. conditions. Delivery of packages within the plant should in the individual's dose should be determined and entered also be monitored when carried by personnel rather than should be personnel dosimetry record. Complete records mechanical conveyors. Surveys should be made to deter maintained of each incident of this nature. mine when carts rather than hand carrying should be used. Packages containing significant amounts of radioactive mate large quantities Since manufacturing plants often process rials should not be surveyed or opened until the containers programs of unencapsulated radioactive material, bioassay have been placed in the appropriate protective facility such are may be required. Acceptable features of such programs as a radiological-type fume hood or hot cell. published in Regulatory Guides 8.9, "Acceptable Concepts, Program," Models, Equations, and Assumptions for a Bioassay No packages should be released for shipment or transfer to 8.20, 8.11, "Applications of Bioassay for Uranium," and other users unless contamination levels of internal sources or are issued "Application of Bioassay for 1-125 and 1-131," or devices have been tested and certified to meet (a) the Branch. by the License Management criteria of paragraph 35.14(b)(5) of 10 CFR for Group VI products or (b) license conditions for other products as to Unrestrict 1.7 Surveys of Equipment Prior to Release provided in §35.14 or in the manufacturer's license. Also, ed Areas no packages may be released for shipment or transfer when external radiation or surface contamination levels exceed be conducted for Surface contamination surveys should limits set by the Department of Transportation in Title 49 before potentially both removable and fixed contamination of the Code of Federal Regulations. External radiation and from restricted to un contaminated equipment is released contamination levels should be maintained ALARA. restricted areas. If contamination is detected, decontamina until contamination Ition procedures should be repeated 1.10 Checks on Posting of Caution Signs, Labels, Signals, Controls, and Notices to Employees 8 Decontamination attempts without the licensee's medical con restricted to washing with mild soap and sultant present should be or at or with soaps specifically manufactured for hand washing, radiation safety staff should perform surveillance water, agreed upon by the The to decontamination procedures previously that signs, labels, signals, other access medical consultant. If such attempts do not reduce the contamina least weekly to ensure tion to acceptable levels, the aid of a physician should be obtained. 8.21-5 controls, and required Notices to Employees, copies of should be calibrated as are logarithmic readout instru licenses, and other items are properly posted, legible, and ments. Survey instruments should also be calibrated follow operative, as required by 10 CFR Part 19, "Notices, Instruc ing repair. A survey instrument may be considered properly tions and Reports to Workers; Inspections," and Part 20 or calibrated when the instrument readings are within + 10 license conditions. Radiation alarm signals and access con percent of the calculated or known values for each point trols should be tested to verify that they will operate pro checked. Readings within + 20 percent are considered perly under both the normal and abnormal conditions that acceptable if a calibration chart or graph is prepared and might be expected to occur. Care should be taken to mini attached to the instrument. mize exposure to personnel who are conducting the tests. Any signs, labels, or notices found to be missing should 1.13 Surveys of Protective Clothing Before and After be promptly replaced. Temporary signs, signals, or barriers Laundering together with appropriate worker notification and instruc tion may be used in the interim when items as specified in All garments with contamination levels exceeding those 10 CFR Parts 19 and 20 are not available, but acceptable given on line 3 of Table 2 should be either disposed of as corrections should be provided as soon as practicable. radioactive waste or properly surveyed, packaged, and labeled and sent to a laundry licensed to process and handle 1.11 Leak Tests of Sources radioactively contaminated clothing.
Leak testing of sealed sources must be carried out in Each garment returned from a licensed laundry, or a accordance with the terms and conditions of the manu sample of garments that are returned within a single pack facturer's materials license. Also, as provided in para age, should be monitored before use. If contaminationi graphs 35.14(b)(5) and 35.14(e)(1), sealed sources con levels on the garment exceed those given on line 4 of Table taining 2, the garment should not be used.
a. More than 100 microcuries of a byproduct mate 1.14 Ventilation Surveys rial with a half-life of more than 30 days (except iridium 192 seeds encased in nylon ribbon) or Radiation safety, personnel should conduct surveys monthly (or more frequently) to determine the face veloc b. More than 10 microcuries of an alpha emitter ity of air at the entrance of radiological-type fume hoods in use to protect workers against the hazards from unencap must be leak tested for contamination or leakage at 9 inter sulated radioactive materials. Such surveys should be made vals not to exceed 6 months unless a different interval is by using a properly calibrated thermoanemometer, velom specified for a particular manufactured source under the eter, or a U-tube observation after the initial measurement provisions of paragraph 32.74(b). Further provisions and of flow rate to determine whether the airflow has been re exceptions to leak-testing requirements are established in duced to unacceptable levels by filter loading or the mal paragraphs 35.14(b) and 35.14(e)( ). function of blowers, fans, etc. The minimum average face velocity for a fume hood with the sash in the operating 1.12 Calibration of Radiation Safety Instruments position or for an opening in a special enclosure should be 100 ft/min, as determined from at least five Portable different survey instruments should be placed on a rou measurement points. tine maintenance and calibration program that will ensure that properly calibrated and operable survey instruments Corrective action should be taken as soon as possible are available at all times for use by the health physics when the face velocity is found to be deficient. Work staff. should be terminated if the average face velocity falls below 100 ft/min. An adequate calibration of survey instruments cannot be performed solely with built-in check sources. Electronic In addition to these surveys, each enclosure should be calibrations that do not involve a source of radiation also equipped with a device that measures pressure drop across do not determine the proper functioning and response of the hood filter. Workers should be instructed to maintain all components of an instrument. However, an initial cali daily checks of these devices and to notify radiation safety bration with a radiation source and periodic tests using personnel when the pressure drop exceeds a preset level. electronic input signals may be considered adequate for high ranges that are not used routinely. At least annually, or when changes occur that might affect airflow, a survey should be made to determine the Daily or other frequent checks of survey instruments number of air changes per hour provided by the ventilation should be supplemented every 6 months with a calibra system in each room in which work with unencapsulated tion of each instrument at two points separated by at radioactive materials is conducted. A minimum of six changes least 50 percent of each linear scale that is used routinely, per hour should be provided. or with a calibration at one point near the midpoint of each decade on logarithmic scales that are used routinely. Digital 9 readout instruments with either manual or automatic scale Where filtered exhausts are employed, devices such as U-tube switching should be calibrated as are linear readout instru manometers or the equivalent should be provided to indicate the ments. Digital readout instruments without scale switching pressure drop across the filters so that the filters may be changed I before becoming excessively plugged. 8.21-6 1. 15 Surveys of In-Plant Unrestricted Areas enced the selection of appropriate times for performing health physics measurements. Unrestricted areas should be surveyed periodically to ensure that radiation and radioactive material are ade 1.16.2 RegularInventory of RadioactiveMateria4 Audit quately confined in restricted areas, except in cases where of Procedures, and Instruction of Personnel these materials must be transported between areas. Such transportation should be surveyed or planned with the radi The surveillance program includes: ation safety staff. a. Regular inventory of radioactive materials and their 1.15.1 Surface ContaminationSurveys locations,
Removable surface contamination surveys in unrestricted b. Frequent audits of radiation safety procedures and areas should be performed and recorded at frequencies the uses and amounts of material in process compared to consistent with the potential for spreading contamination licensed possession limits, and but not less frequently than quarterly. With the exception of lunch rooms and snack bars, random smear testing of c. Discussions with personnel to ensure their continued floors and furniture is adequate. In lunch rooms and snack awareness of safety procedures and the appropriateness of bars, equipment should also be surveyed. If such surveys their instruction and training for the tasks they are per reveal that radioactive contamination is being transferred forming. out of restricted areas, immediate corrective action should be taken to eliminate such transfers, and decontami These surveillance activities may be conducted during nation efforts in the unrestricted areas should be repeated the performance of other survey measurements or tests. until it is evident that subsequent efforts would not sig The radiation safety staff should conduct surveillance in nificantly reduce contamination levels. If contamination spections in a manufacturing plant at least weekly. The is found in unrestricted areas, surveys should be performed surveillance should be performed at least annually by the on a more frequent schedule as necessary until the source Radiation Safety Officer in the presence of a management of contamination is ascertained and corrected. The appli representative such-as the plant manager to provide manage cant may propose contamination levels, following decon ment with an awareness of the nature and importance of tamination efforts described above, for in-plant unrestricted activities conducted for personnel protection and plant areas. The limits given on line 1 of Table 2 are acceptable safety. to the NRC staff and need not be justified by the applicant. 2. FREQUENCY OF SURVEYS 1.15.2 Radiation Surveys The frequency of routine surveys depends on the nature, Radiation surveys in unrestricted areas should be per quantity, and use of radioactive materials, as well as the formed and recorded at frequencies consistent with the specific protective facilities, equipment, and procedures types and quantities of materials in use but not less fre that are designed to protect the worker from external and quently than quarterly. These surveys should be made in internal exposure. areas adjacent to restricted areas and in all areas through which byproduct materials are transferred and temporar Generally, surveys should be performed before radio ily stored before shipment. Dose rates in these areas should active materials are used in a new facility in order to estab be evaluated to determine whether they comply with the lish a baseline of background radiation levels and radio requirements of § 20.105 of 10 CFR. activity from natural sources, structural components of the facility (including radon and thoron emanation rates and 1.16 Surveillance concentrations), and any already existing operations with radiation sources in nearby rooms or facilities. These base 1.16.1 Surveillance by Individual Performing Surveys line surveys should be performed under the various condi tions of containment, shielding design, and process heat The term surveillance, as used in this section, refers loads to be expected under manufacturing conditions. Sur to observations of radiological working conditions in re veys of simulated process operations with nonradioactive stricted areas made by the person who performs the routine reagents or smaller amounts of radioactive material should radiation and contamination surveys. Such surveillance, one also be performed where appropriate to establish the per of the most important aspects of a radiation protection pro formance of protective equipment and procedures before gram, allows health physics personnel to acquire detailed full-scale production using any new or untested facilities knowledge of each operation in order to (a) identify ways or processes. of preventing or minimizing exposures, (b) select appro priate times for making health physics measurements, and Surveys should be repeated as soon as process operations (c) adequately prepare for emergency conditions. Health begin with normal levels of radioactive material and with all physics personnel should be sufficiently familiar with each potentially exposed workers present and carrying out their operation to explain it in detail, to describe potential haz job functions. Surveys should also be conducted after any ards and the precautions taken to minimize exposures, and significant changes in the conditions that existed at the to discuss how this knowledge of the operation has influ- time of the most recent survey, including changes in the
8.21-7 given in the regula quantities of radioactive material handled or in protective Record retention requirements are that sur equipment and procedures. tions cited above. Paragraph 20.401(c)(2) requires vey records be preserved for 2 years, except that records of (in the absence of personnel monitoring Routine and repetitive surveys are necessary to control air monitoring and t6 determine external radiation the containment of radioactive materials within handling data) records of surveys until the NRC authorizes their systems and to ensure the continued integrity of protective dose are to be maintained equipment and procedures. Surveys are also necessary for disposition. procedures in which sealed sources are handled outside be maintained in logbooks or on special shielded containers. For operations involving materials Records may legible, understandable, and in gas, liquid, or finely divided forms, the survey program forms as long as they are clear, The signature of the should be designed to monitor the continued adequacy of authenticated by authorized personnel. the record and the date of the signature should containment and control of the materials involved. person making be on the same page as the record and should immediately Either the original or a reproduced The minimum acceptable frequencies of surveys for manu follow each record entry. (duly authenticated) may be maintained facturing plants are given in Table 1. The NRC staff considers copy or microform of § 20.401. the frequencies established in Table I to meet the require to meet the storage requirements ments of §20.101 of 10 CFR. D. IMPLEMENTATION
purpose of this section is to provide information to 3. RECORDS OF SURVEYS The applicants and licensees regarding the NRC staff's plans for using this regulatory guide. Reference should be made to §§20.401 and 30.51 and Except in those cases in which the applicant or licensee Parts 31-35 of 10 CFR for recordkeeping requirements an acceptable alternative method, the staff will regarding surveys related to the receipt, use, packaging, proposes described herein in evaluating an appli transfer, export, and disposal of byproduct material. Sec use the methods capability for and performance in com tion 20.401 requires that licensees maintain records in the cant's or licensee's plying with specified portions of the Commission's regula same units used in Part 20. Thus, external exposure rates tions after November 15, 1979. should be recorded in estimated maximum dose equivalent units to relevant parts of the body as specified in 10 CFR If an applicant or licensee wishes to use the method Part 20. Air concentration measurement results should be described in this regulatory guide on or before Novem-I recorded in units of .LCi/ml, and surface contamination ber 15, 1979, the pertinent portions of the application or measurement results should be recorded in units of dpm/ 2 2 the licensee's performance will be evaluated on the basis 100 cm2 , pCi/100 cm , or pCi/cm (or as in §20.5). SI of this guide. unit conversions may be specified as part of the record.
8.21-8 REFERENCES*
1. National Commission on Radiological Protection 15. C. A. Willis, "Safe Specific Activity: A Useful Concept (NCRP) Report No. 8, "Control and Removal of Radio in Monitoring Areas Containing Activated Materials," active Contamination in Laboratories," December 15, Health Physics OperationalMonitoring, Vol. 1, C. A. 1951. Willis and J. S. Handloser, Eds., Gordon and Breach, New York, 1972, p. 373. 2. NCRP Report No. 9, "Recommendations for Waste Disposal of Phosphorus-32 and Iodine-131 for Medi 16. H. J. Deigl, "Guidelines for Determining Frequency cal Users," November 2, 1951. of Wipe Surveys," Health Physics OperationalMoni toring, Vol. 1, C. A. Willis and J. S. Handloser, Eds., 3. NCRP Report No. 10, "Radiological Monitoring Gordon and Breach, New York, 1972, p. 385. Methods and Instruments," April 7, 1952. 17. R. C. Henle and P. E. Bramson, "Evaluation of 4. International Atomic Energy Agency (IAEA) Techni Internally Deposited 2 4 1 Americium from Bioassay cal Report Series No. 120, "Monitoring of Radioac Data," Health Physics Operational Monitoring, Vol. tive Contamination on Surfaces," 1970. 1, C. A. Willis and J. S. Handloser, Eds., Gordon and Breach, New York, 1972, p. 731. 5. IAEA Safety Series No. 38, "Radiation Protection Procedures," 1973. 18. P. G. Voilleque, "Calculation of Expected Urinary and Fecal Excretion Patterns Using the ICRP Task 6. IAEA Safety Series No. 1, "Safe Handling of Radio Force Group Report on the Human Respiratory nuclides," 1973 Edition, Code of Practice Sponsored Tract," Health Physics Operational Monitoring, by the International Atomic Energy Agency (IAEA) Vol. 1, C. A. Willis and J. S. Handloser, Eds., Gordon and the World Health Organization (WHO), 1973. and Breach, New York, 1972, p. 773.
7. IAEA Technical Report Series No. 133, "Handbook 19. R. L. Kathren, "Instruments in the Field Use, Abuse, on Calibration of Radiation Protection Monitoring and Misuse," Health Physics OperationalMonitoring, Instruments," 1971. Vol. 2, C. A. Willis, and J. S. Handloser, Eds., Gordon and Breach, New York, 1972, p. 811. 8. IAEA Safety Series No. 25, "Medical Supervision of Radiation Workers," sponsored jointly by IAEA, 20. W. P. Howell and R. L. Kathren, "Calibration and WHO, and ILO, 1968. Field Use of Ionization Chamber Survey Instru ments," Health Physics Operational Monitoring, 9. International Commission on Radiological Protec Vol. 2, C. A. Willis and J. S. Handloser, Eds., Gordon tion (ICRP) Publication 12, "General Principles of and Breach, New York, 1972, p. 925. Monitoring for Radiation Protection of Workers," Pergamon Press, 1969. 21. A. Brodsky, N. Wald, R. E. Lee, J. Horm, and R. Caldwell, "Plutonium-Americium Contamination 10. AAPM Monograph No. 1, "Biophysical Aspects of Aspects of a Dry Box Incident Involving Hand Ampu the Medical Use of Technetium-99m," J.G. Kereiakes tation," Health Physics Operational Monitoring, Vol. and Karen R. Corey, Editors (available from American 3, C. A. Willis and J. S. Handloser, Eds., Gordon and Association of Physicists in Medicine, Dr. James G. Breach, New York, 1972, p. 1601. Kereiakes, E555 Medical Sciences Building, University of Cincinnati, Cincinnati, Ohio 45267), 1976. 22. F. E. Gallagher, A. N. Tschaeche, C. A. Willis, J. C. Evraets, and J. C. Rogers, "Progress on Surface Con 11. International Commission onRadiationUnitsandMeas tamination Standards," Health Physics Operational urements (ICRU) Report No. 12, "Certification of Stand Monitoring, Vol. 3, C. A. Willis and J. S. Handloser, ardized Radioactive Sources," September 15, 1968. Eds., Gordon and Breach, New York, 1972, p. 1767.
12. NCRP Report No. 57, "Instrumentation and Monitor ing Methods for Radiation Protection," 1978. IAEA reports may be obtained from UNIPUB, Inc., P.O. Box 433, 13. NCRP Report No. 58, "A Handbook of Radioactivity New York, N.Y. 10016. Measurement Procedures," 1978. ICRP reports may be obtained from Pergamon Press, Maxwell House, Fairview Park, Elmsford, New York 10523. 14. C. B. Meinhold, "Facility Monitoring Programs, Tech ICRU reports may be obtained from the International Commission on Radiation Units and Measurements, P.O. Box 30165, Washington, niques, and Problem Solving,"Health Physics Opeattion D.C. 20014. al Monitoring, Vol. 1, C. A. Willis and J. S. Handloser, NCRP reports may be obtained from NCRP Publications, P.O. Eds., Gordon and Breach, New York, 1972, p. 363. Box 30175, Washington, D.C. 20014.
8.21-9 TABLE 1 ACCEPTABLE FREQUENCIES FOR SURVEYS
Amounts (Curies) in Process at Any One Time or Placed into Process in Any 3-Mo. Period Within Any Room Requiring Surveys I External Radiation Surveys Radlonuclide Group (nuclides with asterisks only)* Air Sampling"* Surface Contamination Weekly Monthly Weekly Monthly Quarterly Weekly Monthly Quarterly <10 H-3, C-14. F-I8,* K-42,* If point source of ac If point source of ac 210 <1 ý 100 > 10 1: <10 < 100 Cu-64,* Tc-99m,* In tivity could exceed 50 tivity could exceed 113m* mrad/h at I meter 0.5 mrad/h at I meter <0.1 <0.1 >Z10 > I
Ill: S-35, Au-198, Ca-47, o0.1 z 0.01 <0.01 <0.1 <0. I 0.1 > 0.01 <0.01 IV: Hf-181, Pm-147, P-32,* <0.01 < 0.1 Ba-140,* Th-234, Kr-85, Ir-192,* CI-36, Y-91, Ta P0 i82, Ca-45, Sr-89, Cs-137, Co-60,* Ce-144,* 1-126, Eu-154, 1-131.* 1-125,* 0 Tm-170, Na-22,* Mn-54** Ag-li0m,* Hg-203.* Rn 222,* Sn-1 13" <0.001 V: Tc-99, 1-129, Ru-106 > 0.001 > 10-4 <10-1 2_>0.01 >0.001I <0.001 <0.01 <10-1• > 0.001 > .10-' Z 10-4 > 10-' VI: Ra-223, Po-210. Th-227, < 10-4 < 0.001 Sr-90, Pb-210, Cm-242, U-233*
*Nuclides with asterisks are those more likely to require external radiation surveys. "**Assuming continuous sampling is unnecessary (see Section C. 1.3). TABLE 2
RECOMMENDED ACTION LEVELS FOR REMOVABLE SURFACE CONTAMINATION IN MANUFACTURING PLANTS
Type of Radioactive Materiala
Alpha Emitters Low-Risk High Lower Beta or X-Ray Beta or X-Ray Toxicity Toxicity Emitters Emitters 2 2 2 2 (PCi/cm ) Type of Surface (PCi/cm ) (PCi/cm ) (pCi/cm )
10" 10-6 10-6 1. Unrestricted areasb 10-7 10-3 103 10-2 2. Restricted areasc 10 -4 6 10-7 10- 10-6 3. Personal clothing worn outside 10"7 of restricted areas 10"- 10r4 10-4 4. Protective clothing worn only in 10"5 restricted areas
aHigh toxicity alpha emitters include Am-243, Am-241, Np-237, Ac-227, Th-230, Pu-242, Pu-238, Pu-240, Pu-239, Th-228, and Cf-252. Ra-226 (s) in 10 CFR Part 20, Appen alpha emitters include those having permissible concentrations in air greater than that for Lower toxicity emitters other than those considered low risk. Low dix B, Table I, Column 1. Beta or x-ray emitter values are applicable for all beta or x-ray or x-ray emission is less than 0.1 R/h at 1 meter per curie, risk nuclides include those whose beta energies are less than 0.2 MeV, whose gamma than 10-6 ACi/ml. and whose permissible concentration in air in 10 CFR Part 20, Appendix B, Table 1, is greater in level of bContamination limits for unrestricted (non-contamination-controlled) areas in this table are considered to be compatible ulatory Guide 1.86, "Termination of Operating safety with those for release of facilities and equipment for unrestricted use, as given in Re for Decontamination of Facilities and Equipment Prir to Release for Unrestricted Use Licenses for Nuclear Reactors," and in "Guidelines of Fuel Cycle and Licenses for Byproduct, Source, or Special Nuclear Material," which is available from the Division or Termination of Washington, D.C. 20555. Material Safety, Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, walls, and ceiling, cAs adapted from Table I of Reference 4. Averaging is acceptable over inanimate areas of up to 300 cm2 or, for floors, is worn. 100 cm'. These limits are allowed only in those restricted areas where appropriate protective clothing 2 units adopted as national standards Units: The above units of pci/cm have been used in this table since they are consistent with Note on used to express concentration in 10 CFR Part several other nations and the IAEA (see Reference 6); the units of pCi and cm are already in dis/sec = 3.7 x 1.0 Becquere.s (Bq). They may 20, and they are readily convertible to SI units by the well-known relation; I pCi•04 = 3.? x 2 i.e., disintegrations/minute per 100 cm 2.22 x also be easily converted to other Jrequently used units of radiation protection practice, 10* x (activity expressed in p.Ci/cm ). un Skin contamination should always be kept ALARA. Exposed areas of the body of persons working with Note on Skin Contamination: It is important, how materials should always be monitored and should be washed when any contamination is detected. sealed radioactive into the body is increased. See ever, that contaminated skin should not be so treated or scrubbed that the chance of intake of radioactivity Section 1.6 of this guide.
8.21-11 FIRST CLASS MAIL UNITED STATES POSTAGE & FEES PAID NUCLEAR REGULATORY COMMISSION USNAC WASHINGTON, D.C. 20555 PERMIT No G.67
OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, $300