ML24081A131
| ML24081A131 | |
| Person / Time | |
|---|---|
| Issue date: | 06/04/2024 |
| From: | Russell Felts, Mike Franovich NRC/NRR/DRO |
| To: | Dan Collins, Mark Franke, Jason Kozal, Geoffrey Miller, Ladonna Suggs Division of Operating Reactors, Division Reactor Projects II, Division of Reactor Safety II, Division of Operating Reactors, NRC/RGN-IV/DORS |
| References | |
| Download: ML24081A131 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 MEMORANDUM TO:
Daniel Collins, Director Division of Operating Reactor Safety, Region I LaDonna Suggs, Director Division of Reactor Safety Region II Mark Franke, Director Division of Reactor Projects Region II Jason Kozal, Director Division of Operating Reactor Safety, Region III Geoff Miller, Director Division of Operating Reactor Safety, Region IV FROM:
Russell N. Felts, Director Division of Reactor Oversight Office of Nuclear Reactor Regulation Michael R. Franovich, Director Division of Risk Assessment Office of Nuclear Reactor Regulation
SUBJECT:
ESTABLISHMENT OF PROBABILISTIC RISK ASSESSMENT CONFIGURATION CONTROL INSPECTION CROSS-REGIONAL PANELS This memorandum establishes cross-regional panels to promote consistent application and resolution of inspection findings and violations, and associated proposed enforcement actions, identified through implementation of the Probabilistic Risk Assessment (PRA) Configuration Control (CC) Operating Experience Smart Sample (OpESS) 2023-02 (Agencywide Documents Access and Management System Accession No. ML23255A006). Per the generic charter for topic-specific cross-regional panels (ML18232A192), topic-specific cross-regional panels will be CONTACT: Lundy Pressley, NRR/DRA Alexander Garmoe, NRR/DRO 404-997-4621 301-415-3814 June 4, 2024 Signed by Felts, Russell on 06/04/24 Khanna, Meena signing on behalf of Franovich, Michael on 06/03/24
D. Collins et al, 2
staffed by representatives from the program office and the regions. Additionally, these panels record and share their results for knowledge management and training purposes.
The topic of PRA CC cross-regional panels was discussed at the March 2023 Division Director Counterpart Meeting and the attendees approved moving forward to develop topic-specific guidance and implement the panels once the OpESS was finalized.
All proposed PRA CC findings or violations identified via OpESS 2023-02 will be brought to a cross-regional panel. Enclosure 2 of this memorandum is provided to assist with screening PRA CC issues through the existing issue screening and significance evaluation guidance. Any findings that do not screen to Green will continue through the Significance Determination Process.
Panels formed under the generic charter, including these PRA CC Panels, are temporary and remain in existence until there is sufficient familiarity and direction with how to disposition such inspection findings and issues. Once sufficient familiarity and consistency has been achieved, a discussion of dissolving the topic-specific panels will be brought to the Division of Reactor Oversight (DRO) and a regional directors call. The topic can then be added to the next Division Director Counterpart Meeting for a full discussion and decision. Following this discussion, the panel can be ended with DRO Director approval.
Participation in the panels is indicated in the table below. A quorum is required for initial presentation and final issue resolution, and attendees required for quorum constitute voting members. In preparation for each meeting, the presenter shall complete the panel template for each issue that will be presented (e.g., if there are two issues at one site, two templates will be completed) and provide it to the panel chair at least four working days prior to the meeting to share with all participants in advance.
List of Participants IRAB Branch Chief or designee*
Chair and Participant APOB Branch Chief or designee*
Participant Regional Branch Chief responsible for inspection that identified the issue*
Participant Senior Reactor Analyst (SRA) or Reliability and Risk Analyst (RRA) from DRO or DRA*
Participant SRA from regional office Participant Lead Inspector Presenter and Participant Regional Enforcement Coordinator*
Participant NRR Enforcement Coordinator Participant Staff technical experts, as needed Participant
- Voting members and required for quorum The panel chair will facilitate the discussion and help the panel reach consensus on the final disposition of the issue of concern, performance deficiency, and inspection finding. Similar to Significance and Enforcement Review Panel (SERP) consensus decision-making, unanimous agreement of the cross-regional panel voting members is not needed to establish consensus.
Rather, a consensus decision is one in which all members at least generally accept the position, agreement, or decision reached. Each panel member may question or challenge any of the information and analyses presented. If consensus is not reached at the conclusion of the panel,
D. Collins et al, 3
the issue will be elevated to a discussion between the Division Directors, Deputies, or designees of the Division of Reactor Oversight and Division of Risk Assessment in NRR and the regional technical division for a decision. For potentially greater than green issues, the SERP process will be followed. The panels decision will serve as the final more-than-minor determination for these performance deficiencies.
The lead inspector or inspection team leader will place the completed template into the Agencywide Documents Access and Management System as non-public document sensitivity A.7. The ADAMS Accession number for the panel decision will be made available to regional staff on the NRR/DRO/IRAB SharePoint site. The final panel template documentation should be posted on the DRO Reactor Inspection Branch SharePoint site.
Enclosures:
1.
PRA Configuration Control OpESS Panel Template 2.
PRA Configuration Control Issue Screening Guidance
ML24081A131 NRR-106 OFFICE NRR/DRO/IRAB NRR/DRA/APOB NRR/DRO/IRAB NAME AGarmoe AZoulis PFinney DATE 3/22/2024 5/24/2024 5/28/2024 OFFICE NRR/DRA NRR/DRO NAME MFranovich RFelts DATE 6/3/2024 6/4/2024 PRA Configuration Control OpESS Panel Template Note: The standard IMC 0611 four-part write-up can be submitted in lieu of this worksheet.
Date of Panel Inspection Date Licensee Exit Date Region Report Number IRAB BC (Panel Chair)*
APOB BC*
Regional BC*
Regional SRA DRO or DRA SRA/RRA*
Lead Inspector Regional Enforcement Coordinator*
NRR Enforcement Coordinator Other Staff
- Voting member and required for quorum Performance deficiency (including regulation or standard not met)
Brief summary of the issue Minor/more-than-minor (including basis) and proposed significance
2 PRA Configuration Control OpESS Panel Template Cross-cutting aspect and basis Enforcement (if applicable)
Comments Decision Reached PRA Configuration Control Issue Screening Guidance Objectives:
This screening guidance is being provided to aid in achieving consistent treatment and resolution of probabilistic risk assessment (PRA) configuration control (CC) issues identified via Operating Experience Smart Sample (OpESS) 23-02, or other inspections, and to assist with processing PRA CC issues through existing issue screening and significance evaluation guidance. Issues with PRA CC should be screened and evaluated using existing guidance in Inspection Manual Chapter (IMC) 0612, Issue Screening, and IMC 0609, Significance Determination Process, and its appendices, as appropriate, informed by the guidance herein.
Consistent with existing guidance for identifying and processing issues of concern, inspectors should generally cite the highest-level applicable requirement (e.g., Technical Specification violations for Risk Informed Completion Time (RICT) issues).
For any identified performance deficiencies (PDs), the most applicable risk-informed program that is affected by the specific error and/or has the most impact should be determined, and the issue should be pursued against that risk-informed program. Consistent with NRC Enforcement Manual (ADAMS Accession No. ML23360A760), staff should follow the guidance contained in Part 1, Sections 1.3.4 and 1.3.5, related to documenting multiple examples of a violation when applicable.
Deviations from this guidance contained within this memo should be discussed with a senior reactor analyst (SRA) or risk and reliability analyst and should be explained to the cross-regional panel when the issue is presented.
Utilize the following guidelines while screening the issue through IMC 0612, Appendix B:
Figure 1: Issue Screening, Blocks TE1 and TE2: Willfulness and Traditional Enforcement For Blocks TE1 and TE2 follow the guidelines as stated within IMC 0612, Appendix B. Normally PRA CC issues would follow the Reactor Oversight Process (ROP) path.
Block 3: Is there a performance deficiency?
Q1: Was the issue a result of the licensees failure to meet a requirement or standard?
A1: If inspectors determine the licensee is not meeting applicable requirements or licensee self-imposed standards for PRA CC, which are typically contained within the implementing rule, license amendment, licensee procedures, or ultimately the PRA standard and Regulatory Guide 1.200, then the answer to this question should be yes. Typically, this would be answered as failure to meet ASME PRA Standard as required by implementing Rule or License requirements, (e.g., 50.69, NFPA 805, Surveillance Frequency Control Program (SFCP), or RICT).
Q2: Was the cause of the issue of concern reasonably within the licensees ability to foresee and correct and should the issue of concern have been prevented?
A2: The answer to this question for PRA CC issues would generally be yes, as PRA CC is a requirement for use of risk-informed programs. However, inspectors should use the same discretion with answering this question as with other issues. Ultimately, maintaining the PRA and the use of programs to do so as required by the PRA Standard should be reasonably within the purview of the licensee to perform in order for the PRA to match the as-built as-operated plant.
2 Block 4: Is the performance deficiency (PD) More-than-Minor?
Typically answered as If left uncorrected, the PD would have the potential to lead to a more significant safety concern. However, depending on the situation, the issue could also or alternatively impact a cornerstone objective, (most likely the mitigating systems cornerstone objective associated with availability and reliability). Specifically, the PRA CC issue could result in an incorrect or nonconservative assessment of risk to the plant; for example, an erroneous RICT backstop calculation. For details on the more-than-minor questions refer to IMC 0612, Section 05.01b and c.
The most applicable examples from IMC 0612, Appendix E, Examples of Minor Issues, are likely from Section 8, Maintenance Rule, however, examples from other sections may be more applicable, given the circumstances of the specific PRA CC issue. Inspectors should be aware that the IMC 0612, Appendix E examples at present are not specifically written for PRA CC issues. One of the key considerations in determining if a PRA CC is more than minor is whether the issue affected a PRA-informed calculation or decision outcome in a non-conservative manner or introduced reasonable doubt on the outcome, which can be informed at least in part by the existing suite of examples. The PRA CC Working Group has developed PRA CC-specific examples, which will be updated as needed based on experience with PRA CC issue screening, and will eventually be incorporated into IMC 0612, Appendix E. The PRA CC-specific examples are currently contained in a standalone document (ADAMS package ML24152A029) and should be referred to for consideration when screening PRA CC issues.
Block 5: Does the finding screen to Green?
IMC 0609, Attachment 4, Initial Characterization of Findings Table 1, Finding is typically failure to maintain PRA CC program.
Table 2, PRA CC issues are likely to be contributors in either the Initiating Event (IE) or Mitigating Systems (MS) cornerstones. The specific attributes typically adversely affected are likely one of the following: design control, configuration control or equipment performance.
The most applicable blocks to check for screening:
IE - E. External Event initiators (i.e., incorrect inputs) and MS - A. MS and PRA Functionality, B. External Event, E. Flex (i.e., PRA inputs incorrect).
Table 3, SDP Appendix Router All PRA CC issues should be routed to Section C, Maintenance Rule Risk Assessments, as a general guideline. Does the finding involve the licensees assessment of and management of risk? If so, then proceed to IMC 0609, Appendix K. In this application for PRA CC issues no additional information is required related to 10 CFR 50.65, and it is sufficient to proceed.
It is generally presumed that most PRA CC issues routed to IMC 0609, Appendix K will screen to Green after clearing the more than minor threshold. In the event a PRA CC issue does not screen to Green, additional case by case screening will be performed, and consultation with the SRA community and/or the licensee will be necessary in such cases.
IMC 0609, Attachment 4, will be revised to include a reference to an underestimation of PRA Configuration Risk, which would also be routed to IMC 0609, Appendix K. Additionally, an upcoming revision to IMC 0609, Appendix K, will include additional guidance for assessing risk-informed programs and PRA configuration risk.
3 Utilize the following guidelines while evaluating the issue in accordance with IMC 0609, Appendix K:
1.
Incremental Core Damage Probability (ICDP) Deficit (ICDPD) should be utilized. See of IMC 0609, Appendix K for further details.
ICDPD = ICDP Actual - ICDP Flawed If ICDPD less than or equal to 1E-6 then Green, If ICDPD greater than 1E-6 perform a detailed risk evaluation.
2.
Duration should be limited to a maximum of 1 year, or the date of the model change that introduced the issue if less than 1 year, or other appropriate exposure metrics as determined by inspectors with appropriate justification to the cross-regional panel.
3.
Nominal modeling methods for test and maintenance may be utilized as appropriate for long term exposure times, however for RICT scenarios a zero-maintenance model may be more applicable at the SRAs discretion.
4.
A licensees PRA-based risk evaluation may serve as the basis for screening a finding to Green, in accordance with Step 4.1.1. If the licensees ICDPD is less than 1E-6, then the issue may immediately screen to Green, with SRA approval, based upon the best available information. Or, at the discretion of the SRA, an independent bounding analysis may be performed and if the ICDPD is less than 1E-6, then the issue may also immediately screen to Green. Following the SRA review, in coordination with the cross-regional panel, it may be determined that no additional resources are needed and conclude the finding is Green.
5.
If there are concerns with the licensees risk evaluation, or at the discretion of the SRA, an independent analysis of the evaluation of risk may be performed in accordance with Step 4.1.2.
6.
If a detailed risk evaluation is required, utilize Flowchart 1 and Step 4.2 of IMC 0609, Appendix K as a general guideline for determining the significance of the finding. Risk management actions (RMAs) are generally not applicable to PCC issues and should be ignored for these SDPs, however this may be dependent upon the situation. For example, RMAs may be an input on the determination for any issues involving RICT. The appropriate utilization of RMAs into the analysis is at the discretion of the SRA.
7.
If the above guidelines are insufficient, then inspectors in coordination with the regional SRAs should engage with NRR/DRA/APOB technical staff to propose a reasonable solution, which would also be presented to the cross-regional panel.