ML20268C271
| ML20268C271 | |
| Person / Time | |
|---|---|
| Site: | Nuclear Energy Institute, 99902028 |
| Issue date: | 09/24/2020 |
| From: | Nichol M Nuclear Energy Institute |
| To: | Renee Taylor Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML20268C271 (7) | |
Text
MARCUS R. NICHOL Senior Director, New Reactors 1201 F Street, NW, Suite 1100 Washington, DC 20004 P: 202.739.8131 mrn@nei.org nei.org September 24, 2020 Mr. Robert Taylor Deputy Director for New Reactors, Office of Nuclear Regulatory Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Part 50/52 Lessons Learned Rulemaking - Addressing the term Essentially Complete Project Number: 689
Dear Mr. Taylor:
I am writing on behalf of the Nuclear Energy Institute (NEI)1 and its members to provide input for the NRC staffs consideration as it develops the draft regulatory basis for the Part 50/52 Lessons Learned Rulemaking. In particular, we believe it is important that the rulemaking address the definition and use of the term an essentially complete nuclear power plant design. This issue was discussed in a public meeting conducted earlier this year. Although the industry recommended that additional public meetings be conducted to support development of the draft regulatory basis, the staff has opted not to hold further meetings until after the draft regulatory basis is published for public comment. Therefore, we provide herein suggested changes to 10 CFR Part 52 and the supporting rationale to further inform the staffs consideration of issues associated with the use and interpretation of the essentially complete nuclear power plant design concept.
The term an essentially complete nuclear power plant design or slight variation thereof (i.e., an essentially complete nuclear power reactor design) is used in three places in current Part 52: 10 CFR 52.41(b)(1) and 52.47(c)(1) and (2). As noted the Statements of Consideration (SOC) accompanying the 1989 Final Part 52 rule, an "essentially complete nuclear power plant" is defined as a design which includes all structures, systems and components (SSCs) that can affect safe operation of the plant, except for site-specific features 1 The Nuclear Energy Institute (NEI) is responsible for establishing unified policy on behalf of its members relating to matters affecting the nuclear energy industry, including the regulatory aspects of generic operational and technical issues. NEIs members include entities licensed to operate commercial nuclear power plants in the United States, nuclear plant designers, major architect and engineering firms, fuel cycle facilities, nuclear materials licensees, and other organizations involved in the nuclear energy industry.
Mr. Robert Taylor September 24, 2020 Page 2 such as the service water intake structure and the ultimate heat sink.2 In addition, the SOC specifies that an essentially complete design is a design that has been finalized to the point that procurement specifications and construction and installation specifications can be completed and made available for audit, if it is determined that such specifications are required for Commission review in accordance with 10 CFR 52.47(a).3 The concept of an essentially complete design can be traced to the Commissions 1987 Policy Statement on Standardization.4 The stated purpose of that policy was to encourage the use of standard plant designs
... which are essentially complete in both scope and level of detail.5 Thus, the Commission established therein that essentially complete pertains to two distinct aspects of plant design completion1) scope and
- 2) level of detaila concept that was subsequently reflected in the 1988 proposed Part 52 rulemaking,6 but not clearly articulated in the 1989 final Part 52 rulemaking.
While design scope and level of design detail are distinct issues for a designer, the NRCs current definition of essentially complete nuclear power plant design conflates these two disparate inquiries. Therefore, the NRCs rulemaking should clarify the meaning of essentially complete by addressing design scope and level of detail separately, as intended by the Commission.
Application Scope With regard to the scope of design, the design certification (DC) requirements should maintain essentially complete as the standard only for the scope of plant design to be certified. The Part 52 regulatory history provides support for this approach:
The 1987 Policy Statement states that it excludes features of the design which can only be determined when a specific site is chosen and other features of the design which are dependent on the site.7 The 1988 Proposed Rule would have allowed for certification of a major portion of a facility.8 As noted above, the proposed rule actually distinguished between scope (which was to be essentially complete, unless it was a major portion application) and the necessary level of detail. Site-specific 2 Early Site Permits; Standard Design Certifications; and Combined Licenses for Nuclear Power Reactors; Final Rule, 54 Fed. Reg. 15,372, 15,382 (Apr. 18, 1989) (1989 Final Rule).
3 Id.
4 Nuclear Power Plant Standardization; Policy Statement, 52 Fed. Reg. 34,884 (Sept. 15, 1987) (1987 Policy Statement).
5 Id. 34,884, 34,885.
6 See Early Site Permits; Standard Design Certifications; and Combined Licenses for Nuclear Power Reactors; Proposed Rule, 53 Fed. Reg.
32,060 (Aug. 23, 1988) (1988 Proposed Rule) (noting that it is possible to... to have designs essentially complete in scope and level of detail prior to construction).
7 1987 Policy Statement, 52 Fed. Reg. at 34,886.
8 1988 Proposed Rule, 53 Fed. Reg. at 32,064, 32,067.
Mr. Robert Taylor September 24, 2020 Page 3 elements were excluded from essentially complete scope.9 In justifying the preference for essentially complete designs (versus major portion), the 1988 Proposed Rule also notes that such designs would make more straight-forward the preparation of a probabilistic risk analysis [PRA]
and safety analysis and would help minimize the extent of the staff's review of the license applications which reference a single design. Such designs would also help assure that no two plants of the same design would vary significantly from each other.10 Thus, essentially complete scope is expressly tied to reducing repetitive reviews of portions of the design that are not dependent upon site-specific elements and implements the goal of design standardization.
The 1989 Final Rule adopts the requirement that an essentially complete design is one that (1) include[s] safe operation of the plant except its site-specific elements and (2) is finalized to the point that procurement specifications and construction and installation specifications can be completed. 11 Thus, in defining essentially complete scope, the staff should reflect this regulatory history and clarify the terms implementation. The term might be defined similarly to how it was in the final rule:
A design which includes all structures, systems, and components which can affect safe operation of the plant, except for site-specific elements such as the service water intake structure and the ultimate heat sink. Therefore, those portions of the design that are either site specific (such as the service water intake structure or the ultimate heat sink) or include structures, systems and components which do not affect the safe operation of the facility (such as warehouses and sewage treatment facilities) may be excluded from the scope of design.12 However, for this proposed definition to be fully understood and consistently applied, additional explanation is required for each of its two elements. Site-specific SSCs could benefit from additional criteria. The 1987 Policy Statement provides additional sub-criteria for site-specific SSCs that would be useful to include in the definition: a feature that either can only be determined when a specific site is chosen, or one that is dependent on the site. Each of these sub-criteria, however, could still raise new issues for future designs.
For example, if a facility is proposed for flexible applications, such as electricity or process heat, then are these power conversion features dependent on the site?
In clarifying the meaning of essentially complete scope, the proposed rule should focus on clarifying the meaning of SSCs that can affect safe operation, as this issue has proven to be the most problematic. As currently written, the term affect safe operation creates confusion because it is subjective and does not align with other requirements. The focus should be on what scope of information is needed to provide 9 Id. at 32,073.
10 Id. at 32,064.
11 1989 Final Rule, 54 FR at 15,374, 15,382.
12 Id. at 15,382.
Mr. Robert Taylor September 24, 2020 Page 4 reasonable assurance of adequate protection based on compliance with applicable requirements. Insights can be gained from the scope of the maintenance rule in 10 CFR 50.65(b)(1), or the definition of construction in 10 CFR 50.10(a)(1), and based on these examples, the following could be considered a technology-neutral set of criteria that define the SSC that can affect safe operation:
- 1. Safety-related structures, systems, or components (SSCs) of a facility
- 2. Non-safety-related SSCs
- a. relied upon to mitigate accidents or transients or used in plant emergency operating procedures;
- b. whose failure could prevent safety-related SSCs from fulfilling their safety-related function;
- c. whose failure could cause a reactor scram or actuation of a safety-related system;
- d. that perform risk-significant functions based on insights from the design-specific PRA or are relied upon for long-term safety and to address seismic events.
Clear criteria on the scope of SSCs that can affect safe operation is expected to result in a more efficient and safety focused review. We recommend additional NRC and stakeholder discussion on the criteria, including whether the criteria should be in the rule or guidance, and whether the criteria is sufficiently flexible for different application approaches, for example an approach with more explicit use risk significance.
The intent of this discussion is to focus on the scope of SSCs to be included in an application. We recognize that the scope of an application will also need to include additional information, e.g., programs and technical specifications, that are required to comply with applicable requirements and for the NRC to reach a safety determination.
Level of Detail With regard to level of detail, by defining the scope as discussed above, the rule should separately and more clearly define what is required for level of detail. The level of detail of information should utilize a graded approach that establishes the required level of detail commensurate with an SSCs safety significance, as determined through the use of risk or other considerations such as contribution to defense in depth. Of particular concern with the current 10 CFR 50.47 is the potential for misinterpretation or misapplication of the following phrase in that regulation: The information submitted for a design certification must include performance requirements and design information sufficiently detailed to permit the preparation of acceptance and inspection requirements by the NRC, and procurement specifications and construction and installation specifications by an applicant. Based upon our review of the regulatory history, we conclude that the Commission did not intend for the NRCs safety determination invariably to require consideration of procurement specifications and construction and installation requirements, much less inclusion of that information in the design certification application. In fact, the Commission spoke to this specific issue in the Staff Requirements Memorandum (SRM) for SECY-90-377, which states in relevant part:
Mr. Robert Taylor September 24, 2020 Page 5 The Commission did not require information of the type found in the actual procurement and construction specifications in all instances because it recognized that some degree of flexibility in the level of detail to be submitted was necessary to accommodate as-procured hardware characteristics. Nevertheless, the rule provides that the Commission's safety determinations could require in specific cases that final design information normally contained in certain actual specifications be provided in the application. Consistent with the above, the Commission approves the staff's proposal to take a graded approach to the level of detail, that is, that the level of detail needed for design certification will vary according to a structure's, system's, or component's relationship to safety.13 In conclusion, we do not believe the Commission intended to impose an inflexible, categorical requirement that procurement and construction specifications be included in design certification applications, or that the submittal and review of such applications be contingent upon the completion or initiation of procurement and construction specifications. Indeed, the need for NRC review of procurement and construction specifications for purposes of design certification should be rare. In those rare cases in which the NRC staff concludes that it must review actual procurement and construction specifications to support its safety determination, the staff should notify the applicant of that conclusion as soon as practicable, preferably during pre-application interactions or as part of the NRCs acceptance review to allow sufficient time for the applicant to develop specifications and to inform the NRCs establishment of the review schedule.
Furthermore, as reflected in Part 52 and its regulatory history, there is no requirement that the procurement and construction specifications be placed on the docket; i.e., the NRC can review those specifications (if necessary) through the audit process.14 Proposed Rule Changes As noted above, the term essentially complete is used in three different places in 10 CFR Part 52. We recommend that NRC remove that term entirely from Part 52, and replace it with a clear and precise description of the necessary scope and level of design information required in an application. Specifically, we propose that NRC revise the opening paragraph of 10 CFR 52.47 to clarify the meaning of scope and level of detail as follows:
The application must contain the scope and level of design information15 sufficient to enable the Commission to judge the safety of the applicants proposed design and to reach a final safety determination before the certification is granted. The scope of the design shall be based on the safety-related SSCs, SSCs that are necessary for defense-in-depth, and interface system requirements that can affect the safe operation. This scope excludes site-specific 13 SRM-SECY-90-377, Requirements for Design Certification Under 10 CFR Part 52 at 2-3 (Feb. 15, 1991) (ML003707892) 14 See 10 CFR 52.47; 1989 Final Rule, 54 Fed. Reg. 15,382; SRM-SECY-90377 at 2.
15 The term design information includes both the design and programmatic controls.
Mr. Robert Taylor September 24, 2020 Page 6 elements such as the service water intake structure and the ultimate heat sink. A graded approach shall be used in determining the level of detail in the application. The level of detail of information shall be commensurate with an SSCs safety significance, determined through the use of risk or other considerations such as contribution to defense in depth. The information submitted for a design certification must include performance requirements and design information sufficiently detailed to permit the preparation of acceptance and inspection requirements by the NRC, and procurement specifications and construction and installation specifications by an applicant. Design and programmatic controls can substitute for design information where those controls provide reasonable assurance that the as-built design will meet NRC requirements.
Consistent with the foregoing recommendation to add greater clarity to the rule, the following changes should also be included in the proposed rulemaking. These changes include deleting all current references to term essentially complete and other conforming revisions to the Part 52 regulations:
In 10 CFR 52.41(b)(1), delete the phrase an essentially complete nuclear power plant design and replace it with a nuclear power plant design. The use of essentially complete is unnecessary here.
Revise the opening paragraph of 10 CFR 52.47 to replace the use of the term "essentially complete nuclear power plant" with a more concise description of the necessary scope and level of design information required in an application, as suggested above.
Delete 10 CFR 52.47(c)(1) and (2), as these parts are redundant to the introductory text in 10 CFR 52.47.
Make conforming changes to the Standard Design Approval (SDA) rules. Specifically, revise 10 CFR 52.135(a) to replace the sentence The submittal may consist of either the final design for the entire facility or the final design of major portions thereof with the following sentence: The submittal may consist of either the final design for the entire facility or the final design of major portions thereof and contain the scope and level of design information sufficient to enable the Commission to judge the safety of the applicant's proposed design.
If you have any questions on this matter, please contact me or Mike Tschiltz (mdt@nei.org; 202-471-0277).
Sincerely, Marcus Nichol
Mr. Robert Taylor September 24, 2020 Page 7 c:
Patricia Holahan, Director, Division of Rulemaking, NMSS Anna Bradford, Director Division of New and Renewed Licenses, NRR Mohamed Shams, Director, Division of Advanced Reactors, NRR John Segala, Branch Chief, Division of Advanced Reactors, NRR NRC Document Control Desk