APR1400 Chapter 12, "Radiation Protection," Final Safety Evaluation Report
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12 RADIATION PROTECTION Chapter 12, “Radiation Protection,” of this safety evaluation report (SER) describes the results of the review by the staff of the U.S. Nuclear Regulatory Commission (NRC), hereinafter referred to as the staff, of the Design Control Document (DCD), for the design certification (DC) of the Advanced Power Reactor 1400 (APR1400), submitted by Korea Electric Power Corporation (KEPCO) and Korea Hydro & Nuclear Power Co., Ltd (KHNP), hereinafter referred to as the applicant. This chapter also provides information on facility and equipment design and programs used to meet the radiation protection standards of Title 10 of the Code of Federal Regulations (10 CFR), Part 20, “Standards for Protection Against Radiation,” Part 50, “Domestic Licensing of Production and Utilization Facilities,” and Part 70, “Domestic Licensing of Special Nuclear Material.” The staff evaluated the information in Chapter 12, “Radiation Protection,” of the APR1400 DCD against the guidance in NUREG-0800, “Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition” (hereafter referred to as the SRP), Chapter 12, “Radiation Protection.” Compliance with these criteria provides assurance that doses to workers will be maintained within the occupational dose limits of 10 CFR Part 20, “Standards for Protection Against Radiation.” These occupational dose limits, applicable to workers at NRC- licensed facilities, restrict the sum of the external whole-body dose (deep-dose equivalent) and the committed effective equivalent doses resulting from radioactive material deposited inside the body (deposited through injection, absorption, ingestion, or inhalation) to 50 millisievert (mSv) (5 roentgen equivalent man [rem]) per year with a provision (i.e., by planned special exposure) to extend this dose to 100 mSv (10 rem) per year with a lifetime dose limit of 250 mSv (25 rem) resulting from planned special exposures. The SRP acceptance criteria also provides the guidance for assuring that radiation doses resulting from exposure to radioactive sources both outside and inside the body can be maintained as required by 10 CFR Part 20, including within the specified limits and as low as is reasonably achievable (ALARA). The balancing of internal and external exposure necessary to ensure that the sum of the doses is ALARA is an operational and design concern. An applicant seeking a combined license (COL) must address these operational concerns, as well as programmatic radiation protection concerns. 12.1 Ensuring that Occupational Radiation Exposures Are As Low As (Is) Reasonably Achievable 12.1.1 Introduction As Low As is Reasonably Achievable (ALARA) means making every reasonable effort to maintain exposures to radiation as far as practicable below the dose limits of 10 CFR Part 20. This includes taking into account the state of technology and the economics of improvements in relation to benefits to public health and safety. It also includes using procedures and engineering controls (including adequate design features) based upon sound radiation protection principles. In addition to providing radiation exposure limits for workers and members of the public, 10 CFR 20.1101, “Radiation Protection Programs,” requires that, to the extent practical, procedures and engineering controls based on sound radiation protection principles be 12-1 employed to achieve occupational doses and doses to the public that are ALARA. In addition, 10 CFR 20.1704, “Further restrictions on the use of respiratory protection equipment,” Paragraph (a) requires that the intake of airborne radioactive materials be consistent with maintaining total effective dose equivalent ALARA. Regulatory Guide (RG) 8.8, “Information Relevant to Ensuring that Occupational Radiation Exposures at Nuclear Power Stations Will Be as Low as Is Reasonably Achievable,” provides specific guidance and criteria on the design, construction, and operation of a nuclear power plant to meet this regulatory requirement. Programmatic and policy considerations associated with plant operations that are needed to assure that radiation doses will be ALARA (as discussed in RG 8.8; RG 8.10, “Operating Philosophy for Maintaining Occupational Radiation Exposures as Low as Is Reasonably Achievable”; and RG 1.8, “Qualification and Training of Personnel for Nuclear Power Plants”) are outside the scope of this design certification application (DCA). The applicant has identified COL information items (see Section 12.1.5 of this SER) to ensure that COL applicants referencing the design will address these issues. 12.1.2 Summary of Application DCD Tier 1: DCD Tier 1, Section 2.8, “Radiation Protection,” states that the APR1400 is designed to keep radiation exposures to plant personnel and members of the public within applicable regulatory limits and ALARA. DCD Tier 2: The applicant has provided a DCD Tier 2, Section 12.1, “Ensuring that Occupational Radiation Exposures Are As Low As is Reasonably Achievable,” summarized here in part, as follows: The majority of nuclear plant worker occupational radiation exposure (ORE) results from maintenance on systems that contain radioactive material, radioactive waste handling, in- service inspection, refueling, abnormal operations, and decommissioning work activities. These activities are addressed and included in the design of the APR1400 through the plant physical layout, selection of materials, shielding, and chemistry control. During the design process, ALARA design reviews are periodically conducted. The design is based on experience and lessons learned from operating reactors, which indicate that the design of the facility is important to ensuring occupational doses and doses to the public remain ALARA. Examples of facility design features in the APR1400 design that ensure that the design is ALARA include the separation of radioactive components into individual shielded compartments, remote operating equipment (where possible), to reduce radiation exposure, and the minimization of field run piping, to the extent practicable. A more detailed discussion of design features to ensure exposures to occupational workers and members of the public are ALARA and within applicable dose limits is provided in Section 12.3, “Radiation Protection Design Features,” of this SER. The operational aspects of the radiation protection program (RPP) to provide reasonable assurance that the OREs are ALARA will be provided by the COL applicant as discussed later in this section. Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC): There are no ITAAC associated with the review of DCD Tier 2, Section 12.1. Technical Specifications (TS): There are no TS for this area of review. 12-2 COL Information or Action Items: See Section 12.1.5 below. Technical Report(s): There are no technical reports associated with this area of review. Topical Report(s): There are no topical reports associated with this area of review. APR1400 Interface Issues Identified in the DCD: There are no APR1400 interface issues associated with this area of review. Site Interface Requirements Identified in the DCD: There are no site interface requirements associated with this area of review. Cross-Cutting Requirements (Three Mile Island (TMI), Unresolved Safety Issue (USI)/Generic Safety Issue (GSI), Operating Experience (Op Ex)): Lessons learned from operating reactors was considered in the plant design in addressing the requirements of ALARA. See the 12.1 SRP and the Technical Evaluation Section of this SER for further discussion of this. Title 10 of the Code of Federal Regulations (10 CFR) 20.1406, “Minimization of Contamination”: As part of the ALARA design of the plant, the applicant included numerous 20.1406 design features. These design features are discussed throughout the application and the staff evaluation occurs throughout numerous SER Chapters and Sections. In Chapter 12 of this SER, the evaluation occurs in Section 12.3. Regulatory Treatment of Non-safety Systems (RTNSS): There are no RTNSS issues for this area of review. Conceptual Design Information (CDI): This DCD section does not contain CDI that is outside the scope of the APR1400 certification. 12.1.3 Regulatory Basis The relevant requirements of the Commission’s regulations for ensuring that occupational exposures are ALARA, and the associated acceptance criteria, are given in NUREG-0800, Section 12.1, “Assuring that Occupational Radiation Exposures Are As Low As is Reasonably Achievable,” and summarized below. No review interfaces with other SRP sections are listed in Section 12.1 of NUREG-0800. Acceptance criteria are based on meeting the relevant requirements of the following NRC regulations: 1. Section 19.12, “Instruction to workers,” of 10 CFR, as it relates to keeping workers who receive ORE informed as to the storage, transfer, or use of radioactive materials or radiation in such areas and instructed as to the risk associated with ORE, precautions and procedures to reduce exposures, and the purpose and function of protective devices employed. 2. Section 20.1101, “RPPs,” of 10 CFR and the definition of ALARA in 10 CFR 20.1003, “Definitions,” as they relate to those measures that ensure that radiation exposures resulting from licensed activities are below specified limits and ALARA. 12-3 Specific SRP acceptance criteria for the above requirements are as follows: 1. Policy Considerations: Acceptability will be based on evidence that a policy for ensuring that ORE will be ALARA has been formulated in accordance with the