ML23153A144

Draft SE of Traveler TSTF-591, Revise Risk-Informed Completion Time (RICT) Program

ML23153A144
Person / Time
Site:	Technical Specifications Task Force
Issue date:	09/11/2023
From:	Michelle Honcharik NRC/NRR/DSS/STSB
To:
References
EPID L 2022-PMP-0003
Download: ML23153A144 (7)

Text

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5 DRAFT SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION 6 TECHNICAL SPECIFICATIONS TASK FORCE TRAVELER 7 TSTF-591, REVISION 0, REVISE RISK-INFORMED COMPLETION TIME (RICT) PROGRAM 8 USING THE CONSOLIDATED LINE ITEM IMPROVEMENT PROCESS 9 (EPID L-2022-PMP-0003) 10 11

1.0 INTRODUCTION

12 13 By letter dated March 22, 2022 (Agencywide Documents Access and Management System 14 (ADAMS) Accession No. ML22081A224), the Technical Specifications Task Force (TSTF) 15 submitted Traveler TSTF-591, Revision 0, Revise Risk-Informed Completion Time (RICT) 16 Program, to the U.S. Nuclear Regulatory Commission (NRC); hereafter referred to as 17 TSTF-591. TSTF-591 proposes changes to the Standard Technical Specifications (STSs) for 18 pressurized-water reactor (PWR) and boiling-water reactor (BWR) plant designs. Upon approval 19 this traveler will be made available for adoption and the changes will be incorporated into future 20 revisions of:

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• NRC NUREG-1430, Standard Technical Specifications, Babcock and Wilcox Plants, 22 Volume 1, Specifications, and Volume 2, Bases, Revision 5, September 2021 23 (ML21272A363 and ML21272A370, respectively).

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• NRC NUREG-1431, Standard Technical Specifications, Westinghouse Plants, Volume 1, 25 Specifications, and Volume 2, Bases, Revision 5, September 2021 (ML21259A155 and 26 ML21259A159, respectively).

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• NRC NUREG-1432, Standard Technical Specifications, Combustion Engineering Plants, 28 Volume 1, Specifications, and Volume 2, Bases, Revision 5, September 2021 29 (ML21258A421 and ML21258A424, respectively).

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• NRC NUREG-1433, Standard Technical Specifications, General Electric Plants, BWR/4 31 Volume 1, Specifications, and Volume 2, Bases, Revision 5, September 2021 32 (ML21272A357 and ML21272A358, respectively).

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• NRC NUREG-1434, Standard Technical Specifications, General Electric Plants, BWR/6 34 Volume 1, Specifications, and Volume 2, Bases, Revision 5, September 2021 35 (ML21271A582 and ML21271A596, respectively).

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1 2.0 REGULTORY EVALUATION 2 2.1 Applicable Regulatory Requirements and Guidance 3

4 The regulation under Title 10 of the Code of Federal Regulations (10 CFR) 50.36(b) requires 5 that:

6 7 Each license authorizing operation of a utilization facility will include 8 technical specifications. The technical specifications will be derived from the 9 analyses and evaluation included in the safety analysis report, and amendments 10 thereto, submitted pursuant to [10 CFR] 50.34 [Contents of applications; 11 technical information]. The Commission may include such additional technical 12 specifications as the Commission finds appropriate.

13 14 The categories of items required to be in the TSs are listed in 10 CFR 50.36(c).

15 16 The regulation at 10 CFR 50.36(c)(5), states that administrative controls are the provisions 17 relating to organization and management, procedures, recordkeeping, review and audit, and 18 reporting necessary to assure operation of the facility in a safe manner.

19 20 NRC Regulatory Guides (RGs) provide one way to ensure that the regulations continue to be 21 met. The NRC staff considered the following guidance, along with industry guidance endorsed 22 by the NRC, during its review of the proposed changes:

23 24* RG 1.200, Revision 3, Acceptability of Probabilistic Risk Assessment Results for Risk-Informed 25 Activities, December 2020 (ML20238B871).

26 27* NUREG-0800, Revision 3, Standard Review Plan for the Review of Safety Analysis Reports for 28 Nuclear Power Plants: LWR [light-water reactor] Edition (SRP):

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• Chapter 19, Section 19.2, Review of Risk Information Used to Support Permanent 31 Plant-Specific Changes to the Licensing Basis: General Guidance, dated 32 June 2007 (ML071700658).

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• Section 16.0, Technical Specifications, March 2010 (ML100351425).

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• Section 16.1, Risk-Informed Decision Making: Technical Specifications, 35 March 2007 (ML070380228).

36 37* NEI 06-09-A, Revision 0, Risk-Informed Technical Specifications Initiative 4b, Risk-Managed 38 Technical Specifications (RMTS) Guidelines (ML063390639), provides guidance for 39 risk-informed TS. The NRC staff issued a final model safety evaluation (SE) approving 40 NEI 06-09 on May 17, 2007 (ML071200238).

41 42* NEI 17-07, Revision 2, "Performance of PRA Peer Reviews Using the ASME/ANS PRA 43 Standard," provides guidance material for conducting and documenting a probabilistic risk 44 assessment (PRA) peer review using the American Society of Mechanical Engineers 45 (ASME)/American Nuclear Society (ANS) PRA Standard, issued August 2019 (ML19231A182).

46 47* PWR Owners Group (PWROG) topical report PWROG-19027-NP, Revision 2, "Newly 48 Developed Method Requirements and Peer Review," establishes the definitions, processes, and 49 technical requirements necessary to implement newly developed methods (NDMs), issued

1 July 2020 (ML20213C660). RG 1.200, Revision 3, endorsed only specified portions of 2 PWROG-19027-NP.

3 4 2.2 Proposed Changes to Standard Technical Specifications 5

6 The proposed change revises the STS Section 5.5 Program, Risk Informed Completion Time 7 Program, by referencing RG 1.200, Revision 3, instead of Revision 2. It also adds a 8 requirement in TS Section 5.6, Reporting Requirements for the licensee to submit a report to 9 the NRC before calculating a RICT using an NDM.

10 11 2.2.1 STS 5.5.201 Risk Informed Completion Time Program 12 13 STS 5.5.20, which describes the RICT program, is revised as shown below. Existing 14 paragraph e would be replaced with the paragraph e below. Paragraphs f and g would be 15 added.

16 17 e. A RICT calculation must include the following hazard groups: [list specific 18 hazards and the associated PRA models or alternate means of assessing 19 the hazard for each applicable hazard group approved by NRC. For 20 example, internal flood and internal events PRA model, internal fire PRA 21 model, and seismic penalty factor]. Changes to these means of assessing 22 the hazard groups require prior NRC approval.

23 24 f. The PRA models used to calculate a RICT shall be maintained and 25 upgraded in accordance with the processes endorsed in the regulatory 26 positions of Regulatory Guide 1.200, Revision 3, "Acceptability of 27 Probabilistic Risk Assessment Results for Risk-Informed Activities."

28 29 g. A report shall be submitted in accordance with Specification 5.6.[X] before 30 a newly developed method is used to calculate a RICT.]

31 32 2.2.2 STS 5.6.82, Risk Informed Completion Time Program Upgrade Report 33 34 The following would be added as STS 5.6.8:

35 36 Risk Informed Completion Time (RICT) Program Upgrade Report 37 38 A report describing newly developed methods and their implementation must be 39 submitted following a probabilistic risk assessment (PRA) upgrade associated 40 with newly developed methods and prior to the first use of those methods to 41 calculate a RICT. The report shall include:

42 43 a. The PRA models upgraded to include newly developed methods; 44 1 STS 5.5.20 is the specification number for NUREGs-1430, -1431, and -1432. The number is STS 5.5.17 in NUREGs-1433 and -1434. STS 5.5.20 is used throughout this SE for simplicity.

2 STS 5.6.8 is the specification number for NUREGs-1430, -1431, and -1432. The number is STS 5.6.6 and STS 5.6.7 in NUREGs-1433 and -1434, respectively. STS 5.6.8 is used throughout this SE for simplicity.

1 b. A description of the acceptability of the newly developed methods 2 consistent with Section 5.2 of PWROG-19027-NP, Revision 2, "Newly 3 Developed Method Requirements and Peer Review;"

4 5 c. Any open findings from the peer-review of the implementation of the 6 newly developed methods and how those findings were dispositioned; 7 and 8

9 d. All changes to key assumptions related to newly developed methods or 10 their implementation.

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3.0 TECHNICAL EVALUATION

13 14 Historical Background 15 16 In the final model SE for traveler TSTF-505 (ML18269A041), the NRC staff found the guidance 17 in NEI 06-09, to be acceptable, with clarification from the NRC staff positions, limitations, and 18 conditions. TSTF-505, Revision 2, incorporates the RICT program into the Administrative 19 Controls section of the TS and modifies selected CTs to permit extension provided risk is 20 assessed and managed as described in NEI 06-09-A.

21 22 The NRC staffs SE of TSTF-505, considers determining the acceptability of the licensees PRA 23 models for use in the RICT program, consistent with the guidance provided in RG 1.200, 24 Revisions 2, dated March 1, 2009 (ML090410014).

25 26 PRA acceptability considers the peer review history and results of a licensees PRA model(s).

27 Peer reviews are independent reviews performed by qualified subject matter experts (SMEs) 28 using the requirements established in the ASME/ANS PRA Standards. Office of Management 29 and Budget (OMB), Circular No. A-119 Revised, Federal Participation in the Development and 30 Use of Voluntary Consensus Standards and in Conformity Assessment Activities, establishes 31 policies on federal use and development of voluntary consensus standards on conformity 32 assessment activities. Section 6 of the OMB Circular specifically provides direction on the policy 33 for federal use of standards.

34 35 The ASME/ANS PRA Standard establishes two primary peer reviews that are performed to 36 assess the technical adequacy of the PRA models: (1) full scope and (2) focused scope. The 37 results of a peer review are considered facts and observations (F&Os). An independent 38 assessment review may be performed by qualified SME(s) to assess the licensees satisfactory 39 closure of F&Os. PRA models are a snapshot in time and are continually updated to reflect the 40 as-built, as-operated plant using the technical requirements established in the ASME/ANS PRA 41 Standards along with RG 1.200 guidance to ensure configuration and control is maintained. NEI 42 17-07, as endorsed in RG 1.200, Revision 3, provides industry guidance to perform these peer 43 reviews.

44 45 As the NRC moves forward to make greater use of risk information in decision making, the NRC 46 staff identified enhancements to its risk-informed regulatory framework. One enhancement was 47 the need for a streamlined process to facilitate the acceptance by the NRC and PRA community 48 of NDMs to be used in support of risk-informed applications. The industry developed guidance 49 published in PWROG-19027-NP that addresses, amongst other things, the technical adequacy 50 of NDMs. The NRC staff subsequently endorsed specified portions of PWROG-19027-NP in 51 RG 1.200, Revision 3.

1 2 Evaluation of TSTF-591 3

4 RG 1.200, Revision 3, was issued after the approval of TSTF-505, Revision 2. Traveler 5 TSTF-591 proposes to replace the STS requirement to maintain and upgrade3 the PRA in 6 accordance with RG 1.200, Revision 2, with a requirement to follow RG 1.200, Revision 3.

7 RG 1.200, Revision 3, does not change the factors used to assess PRA technical adequacy and 8 acceptability. Revision 3 of RG 1.200 continues to include guidance to maintain and upgrade 9 the PRA while adding a glossary of key terms, a list of hazards to be considered in the 10 development and use of the PRA, and enhanced guidance related to key assumptions and 11 sources of uncertainty. Furthermore, RG 1.200, Revision 3, does the following:

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• Endorses, with NRC staff exceptions and clarifications, the ASME/ANS RA-S Case 1, 14 Case for ASME/ANS RA-Sb-2013 Standard for Level 1/Large Early Release Frequency 15 Probabilistic Risk Assessment of Nuclear Power Plant Applications, dated 16 November 22, 2017.

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• Endorses NEI 17-07, Revision 2, Performance of PRA Peer Reviews Using the 19 ASME/ANS PRA Standard, issued August 2019.

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• Endorses the following portions of PWROG-19027-NP:

22 o Process for the peer review of NDMs, 23 o Process for determining whether a change to a PRA is classified as PRA 24 maintenance or a PRA upgrade, and 25 o Key definitions related to NDMs, PRA maintenance, and PRA upgrade.

26 27 The proposed language for paragraph e in this traveler incorporates defined terms provided in 28 the glossary of RG 1.200, Revision 3. The NRC staff concludes that the proposed changes 29 using the defined terms provided in RG 1.200, Revision 3, do not introduce any technical 30 discrepancies for the implementation of the RICT program.

31 32 The proposed change to add paragraph f of STS 5.5.20 incorporates a TS requirement that 33 PRA models used to calculate a RICT be maintained and upgraded in accordance with the 34 processes endorsed in the regulatory positions of RG 1.200, Revision 3. RG 1.200 Regulatory 35 Position C.2.2.2.2, states, in part:

36 37 [a]n acceptable approach to performing a peer review for an NDM is the 38 guidance in NEI 17-07, Revision 2. NEI 17-07, Revision 2, [as endorsed by RG 39 1.200, Revision 3,] states, in part, that if an NDM is deemed not technically 40 acceptable in the NDM peer review report, or if at least one finding-level F&O on 41 the NDM remain open, a licensee or applicant may not use it in a PRA supporting 42 risk-informed licensing applications.

43 44 The report that will be submitted to the NRC staff for NDM use in the RICT program can only be 45 used to describe NDMs that are technically acceptable with all the open F&Os resulting from the 3

Per RG 1.200, Revision 3, PRA upgrade is defined as: A change in the PRA that results in the applicability of one or more supporting requirements that were not previously included within the PRA (e.g., performing qualitative screening for Part 4 of ASME/ANS Level 1/LERF PRA Standard when the related high-level requirement was previously not applicable, or adding a new hazard model), an implementation of a PRA method in a different context, or the incorporation of a PRA method not previously used.

1 technical review of the NDM closed using an NRC-endorsed peer review process. Furthermore, 2 in response to Request for Additional Information (RAI) 1.c and 1.d, dated February 1, 2023 3 (ML23032A485), the TSTF confirmed the report cannot be used to satisfy Regulatory 4 Position C.2.2.2.2 and that NDMs with open finding-level F&Os may not be used by a licensee 5 without prior NRC approval. The NRC staff notes that some F&Os may not establish technical 6 inadequacy applicable to the NDM, whereas the F&Os can be plant-specific (e.g., involving 7 implementation). For these open F&Os determined to be plant-specific, consistent with 8 RG 1.200, Revision 3, the licensee can either close the F&O using NRC-endorsed processes or 9 disposition the F&O on a case-by-case basis. The disposition of an F&O involves qualitative or 10 quantitative assessment for impact on the specific risk-informed application. The disposition of 11 F&Os may consider: (1) incorporating appropriate changes into the PRA model prior to use, 12 (2) identifying appropriate sensitivity studies to address the issue identified, or (3) providing 13 adequate justification for the original model, including the applicability of key assumptions to the 14 risk-informed application. The disposition of an F&O does not constitute the F&O to be closed.

15 16 For paragraph g of STS 5.5.20, the traveler proposes to add a TS requirement for a licensee to 17 submit a report before an NDM is used to calculate a RICT. RG 1.200, Revision 3, defines a 18 consensus method/model as follows:

19 20 Consensus method/model: In the context of risk-informed regulatory decisions, 21 a method or model approach that the NRC has used or accepted for the specific 22 risk-informed application for which it is proposed. A consensus method or model 23 may also have a publicly available, published basis and may have been peer 24 reviewed and widely adopted by an appropriate stakeholder group.

25 26 In response to RAI 2.a, example (c) provided, the TSTF stated, [t]he appendix can be made 27 available to the NRC to be loaded on ADAMS (no formal request of review or endorsement 28 would be needed). The use of consensus method(s) by licensees is governed within the 29 guidance of RG 1.200, Revision 3. Consistent with the definition per RG 1.200, Revision 3, and 30 provided above, a consensus method/model is one that has been used or accepted by the NRC 31 for the specific risk-informed application for which it is proposed. Specifically, reporting of an 32 NDM by a licensee under the requirements stipulated in TS 5.6.8 does not justify the NDM to 33 meet the definition of consensus/method/model for future use. Therefore, the NRC staff 34 concludes that for an NDM reported to the NRC under the requirements stipulated in TS 5.6.8 35 for general use of the NDM a licensee must demonstrate the method/model to be consistent 36 with the definition provided in RG 1.200, Revision 3.

37 38 Consistent with RG 1.200, Revision 3, if the NDM has been determined to be acceptable using 39 NRC-endorsed processes, NRC staff action is not needed prior to the licensees use of an NDM 40 in a RICT calculation. The NRC staff finds that the proposed changes to STS 5.5.20 and the 41 addition of STS 5.6.8 remains consistent with the guidance in RG 1.200, Revision 3, that also 42 endorses NEI 17-07, Revision 2, and specific portions of PWROG-19027-NP. Section 4, 43 Tables 1-7.2-1 through 1-7.2-7 of PWROG-19027-NP, as endorsed by the NRC staff, stipulates 44 a list of technical supporting requirements that must be met to determine an NDM acceptable.

45 46 Furthermore, the RICT program is incorporated as a program into the Administrative Controls 47 section of the TS. As described in 10 CFR 50.36(c)(5), administrative controls are the provisions 48 relating to, among other things, recordkeeping and reporting necessary to assure operation of 49 the facility in a safe manner, and each licensee shall submit any reports to the Commission 50 pursuant to approved technical specifications as specified in 10 CFR 50.4.

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1 4.0 TSTF-591 CONDITION 2

3 The NRC staff has identified one condition for the adoption of TSTF-591, Revision 0, applicable 4 to licensees whose plant-specific TS 5.4.1, Procedures, does not include paragraph e that 5 states, in part, TS 5.4.1.e: All programs specified in Specification 5.5. For the adoption of 6 TSTF-591, licensees must ensure for the RICT program that the plant-specific TS includes the 7 requirement for TS 5.4.1 that written procedures shall be established, implemented, and 8 maintained covering the RICT program.

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5.0 CONCLUSION

11 12 The NRC staff concludes the proposed changes to STS 5.5.20 and the addition of STS 5.6.8 13 continue to ensure the PRA models used to calculate a RICT are maintained and upgraded by 14 the licensees appropriate use of endorsed guidance (i.e., the ASME/ANS PRA Standard 15 requirements, and specific industry guidance that the NRC staff has determined are sufficient 16 for determining the acceptability of PRA models and NDMs for use in the RICT program).

17 Furthermore, the NRC staff concludes that the addition of STS 5.6.8 that describes the contents 18 of a RICT program upgrade report to the NRC staff does not preclude any staff oversight of 19 PRA changes performed to ensure the PRA model(s) continues to be maintained and upgraded 20 consistent with RG 1.200, Revision 3.

21 22 The NRC staff finds that the proposed changes are acceptable because they continue to ensure 23 operation of the facility in a safe manner in accordance with 10 CFR 50.36(c)(5). Accordingly, 24 the NRC staff finds TSTF-591 acceptable. Additionally, the NRC staff determined that the 25 proposed TS changes are technically clear and consistent with customary terminology and 26 format in STSs.

27 28 Principle Contributors: Adrienne Brown 29 Andrea Russell 30 Edward Miller