ML24108A174

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Pcc - SDP Workshop Meeting - 18 Apr 24 - Rev.0
ML24108A174
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Issue date: 04/18/2024
From: Lundy Pressley
NRC/NRR/DRA
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PRA Configuration Control (PCC)

Significance Determination Process (SDP)

Meeting

April 18, 2024

Lundy Pressley Reliability and Risk Analyst Office of Nuclear Reactor Regulation Division of Risk Assessment PRA Oversight Branch Meeting Details and Purpose

  • Observation Public Meeting
  • Provides public attendees the opportunity to observe the NRC discussing regulatory issues
  • Continue discussion of NRCs oversight enhancement of PRA Configuration Control (PCC) processes and implementation

2 Meeting Agenda

  • Introductions / Opening Comments
  • NRC Presentation - Background on NRCs OpESS and Inspections
  • NRC Presentation - Background on NRCs SDP Process
  • NRC Presentation - Follow-up discussion on SDP Examples
  • General Q& A / Discussion
  • NEI/Industry Presentation(s)
  • Q&A / Discussion
  • Breaks, as necessary
  • Public Comments / Questions
  • Closing Comments

3 Introductions / Opening Remarks

1) NRC
2) Industry
3) Members of Public PCC Project Milestones

Obtained Issue Public and Conduct Training Issue SDP and Develop Alignment with Recommendations KM Session for Regional Panel long-term NRC Mgt. on Reports on OpESS Guidance oversight process PCC Proposal Tabletops Jan 2024 Spring 2024 2026 / 2027 Mar 2023 Jun 2023

Developed Conduct public Issue Conduct SDP Working Group meeting near-term Workshop and Begin OpESS recommendations Workshop with oversight Gather feedback June 2024 for near-term Tabletop guidance from Industry path forward sites/Industry (OpESS) Winter 2023-2024 Stakeholders Jan 2024 Feb/Jun 2023 Mar 2023

5 Key Messages

Multiple Regulatory requirements for PCC.

If the PRA is not maintained, reflective of the as-built, as-operated plant, then risk estimates and risk decisions could be impacted.

Current inspections have touchpoints to review certain aspects of the PRA, and the OpESS provides additional inspection guidance.

Cross-regional review panels will ensure consistent application across the Regional Offices for any issues identified and SDPs.

Current proposed oversight of PCC does not create any new policies or new enforcement precedents.

6 6 OpESS Background

OpESSis an inspector tool to aid inspection preparation.

Information and trends identified from OpESS may inform future agency action, (if warranted).

OpESS recommendation was developed from voluntary Tabletops initiative, which was a joint effort between NRC and Industry.

The OpESS was issued (ML23255A006).

Applicable to Inspection Procedures (IP):

  • 71111.21N.05, Fire Protection Team Inspection (FTPI)
  • 7 1111. 0 6, Flood Protection Measures
  • 7 1111. 1 3, Maintenance Risk Assessments and Emergent Work Control
  • 7 1111. 1 8, Plant Modifications
  • 7 1111. 2 4, Testing and Maintenance of Equipment Important to Risk
  • 71151, Performance Indicator Verification
  • 71152, Problem Identification and Resolution (PI&R)

7 7 Inspection Implementation / OpESS Applied

1) Focused on PRA Configuration Control and not Acceptability, (does the PRA model accurately reflect the as-built, as-operated plant).
2) Licensee utilizing Risk Informed Programs (RIP).
3) The more RIPs in use, the greater the OpESS applicability.
4) Need sufficient runtime since implementation of RIPs (reasonable time for plant changes).
5) Sample selection based on impactfulplant changes, (both in-progress and completed).
6) SRA oversight and coordination on sample selection.
7) Verify processes are in place to ensure the PRA is maintained.
8) Balanced, performance -based approach.

8 8 SDP Key Points

  • 1
  • Maintain regulatory predictability.
  • Utilize existing processes.
  • Reliable consistent SDP outcomes.
  • Guidance for cross-regional panels is currently in DRAFT, (ML24103A179).

NOTE: At present, feedback from the March 18, 2024, Public Meeting has not been implemented in this draft.

9 9 S D P Background IMC 0612, App. B, Issue Screening Figure 1 - Follow ing the ROP Path Only

3 4 I s th e I ss ue of Is th ere a Ye s per for man ce Ye s PD is a c o n ce r n per for m an ce defi c ien cy finding i de nt if i e d defi c ien cy ? M or e-t h an-M in o r ?

No PD No No END PD not MTM END Documented in some cases

10 10 S D P Background Evaluate IMC 0612, App. B, Issue Screening Document LIV finding Figure 1 - Follow ing the ROP Path Only EN D using IMC 0609 5 6 Ye s

D oe s Ye s Is the finding Ye s the finding D i d the f in di ng sc r een l ic ens ee-invo lv e a i de nt if i e d? violation ?

t o g r ee n ?Screen with IMC 0609, Att. 4 then route to No No applicable No Eval or Doc.

Perform Appendix. No EN D Detailed Risk Evaluation Document FIN/NCV EN D

11 11 S D P Background - PCC Applicability IMC 0612, App. B, Issue Screening

  • Definition: Observation potentially impacting safety which may warrant further inspection, screening, evaluation, or regulatory action.

I ss ue of

  • PCC Application:

c o n ce r n Program weaknesses, i de nt if i e d Program Maintenance,

Program management of changes.

  • Inspectors prioritize issues with greater significance.
  • Issues may end here, however, Inspectors need to understand context.

12 12 SDP Background - PCC Applicability IMC 0612, App. B, Issue Screening

  • Definition: Failure to satisfy one or more regulatory 3 requirements or self-imposed standards where such failure was reasonably foreseeable and preventable.

Is th ere a

  • PCC Application:

per for m an ce Failure to meet regulatory requirement, defi c ien cy ? (PRA Standard, LA, Commitments),

[Non-Cited Violation]

Failure to meet self-imposed standard, (Licensee Program procedures),

Performance Deficiency (PD) [Finding]

  • In PCC context specific to management of changes.
  • If no PD END.

13 13 SDP Background - PCC Applicability IMC 0612, App. B, Issue Screening

  • Could PD reasonably be viewed as a precursor to a significant event ?
  • If left uncorrected, would the PD have the potential to lead to a more significant 4 safety concern?

I s th e

  • Did the PD adversely affect a cornerstone objective? (availability and reliability).

per for m an ce

  • Refer to IMC 0612, App. E, Examples of Minor Issues.

defi c ien cy

  • If yes, then PD is considered a Finding and at a minimum Green, M or e-t h an-regardless of actual risk.

M in o r ?

  • PCC Application:

Cross Regional Review Panel Screening Guidance, DRAFT (ML24103A179),

PCC specific examples (in development),

Significant and impactful, Incorrect or Nonconservative assessment, Reasonable doubt.

  • If Minor, enter issue into CAP, END.
  • May be documented in certain circumstances, (PI&R)

14 14 SDP Background - PCC Applicability IMC 0609, Att. 04, Initial Characterization of Findings

  • Initial Characterization:

5 Table 1, Factual Information Table 2, determine affected cornerstone D oe s Table 3, SDP Appendix Router the finding sc r een

  • PCC Application:

t o g r ee n ? Finding would typically be related to PCC program

Cornerstone objectives: design control, configuration control or equipment performance Screen with Cross Regional Review Panel Screening Guidance, IMC 0609, App. K DRAFT (ML24103A179) ensures all PCC issues routed to IMC 0609, App. K.

15 15 SDP Background - PCC Applicability IMC 0609, App. K Maintenance Risk Assessment and Risk Management SDP

IMC 0609, App. K, (Utilized for General Guidance):

D oe s the finding

  • PCC Application:

sc r een Cross Regional Review Panel Screening Guidance, DRAFT (ML24103A179), IMC 0609, App. K, t o g r ee n ? Limited exposure to 1-year or last model change (whichever is less),

Screened using best available information:

Licensee PRA-based evaluation (Step 4.1.1), or SRA bounding analysis (Step 4.1.2)

If Greater than 1E-6 perform Detailed Risk Evaluation (DRE) > SERP.

General Guidelines of Flowchart 1 and Step 4.2.

Screen with

  • If final determination Green:

IMC 0609, App. K If Finding/NCV, enter intoCAP document in Inspection Report, END If LIV, enter intoCAP, minimal documentation in Inspection Report, END

16 16 SDP Background

  • Cross Regional Review Panel:

Standing NRC practice to address specific issues Promote consistent application and resolution of inspection findings All proposed PCC findings or violations will be brought to the cross regional panel in order to reach consensus Panels are temporary until sufficient familiarity with PCC issues Staffed by representatives from HQ and the regions Panels document the results for future ROP recommendations and for knowledge training

17 17 SDP Background

  • Internal reviews / controls prior to any Final SDPs:

Team Lead/SRA Regional Branch/Management Licensee Feedback Cross Regional Review Panel HQ Oversight Industry Feedback Performance Based Reviews (following sufficient runtime & data)

18 18 SDP Background

  • Timelines:

Report Timeliness: Issued no later than 45 calendar days after inspection completion.

For potentially Greater than Green inspection findings, the goal for SDP timeliness is to complete all final SDPs within 255 days from identification date.

  • Other SDP Items:

Documenting Multiple Examples of a Violation:

Cross Regional Review Panel Guidance will follow existing enforcement guidance on implementation of the Enforcement Program and the ROP as detailed within the NRC Enforcement Manual (ML23360A760).

Specific guidance on this topic is contained in Part 1, Sections 1.3.4 and 1.3.5.

19 19 Questions

20 Industry Presentation

Victoria Anderson Nuclear Energy Institute Key Principles

  • Inspections should examine what has happened, not what could have happened
  • Must be assessed against actual impacts on licensing applications
  • Concept of one finding per performance deficiency should be clearly documented in inspection guidance
  • Can have a cross-cutting impacts No Violation
  • Change to plant wasnt evaluated for inclusion in PRA but there was no impact in the model.
  • Inadequate documentation, but decisions made in or by the model were correct.
  • Identified change not modeled, but not modeling is consistent with utility s PRA configuration control program (refers to timeliness of changes)
  • Includes released data updates Minor Violation
  • Non conser vative impact on PRA model AND
  • PRA model was used in a licensing application (uses an approved L AR such as RICT or 50.69)e. g.

AND

  • Decision was NOT impacted
  • E.g. Amount of actual time spent in RICT would not have changed
  • E.g. Would have changed SSC categorization from LSS to HSS but no alternate treatments have been applied More than Minor Violation
  • Non conser vative impact on PRA model AND
  • PRA model was used in a licensing application ( e. g. uses an approved L AR such as RICT or 50.69)

AND

  • Decision was impacted in a non conser vative manner* Has to impact an actual decision that was made, not a
  • Non conser vativism needs to involve an actual impact on the possible decision decision that increased the risk to the public (e. g. a RICT of 28 days was calculated, but should have only been 25 days and
  • Must involve a regulator y requirement or self-imposed the condition was entered for 26 days) standard Illustration of Process

Involves PRA Used in Issue of Regulator y Relevant 805, 50.69, Concern Requirement Ye sPlant No Documentation Ye s425, 505 Ye sProceed Identified or Self-P ro c e d u re s Inadequate Application Imposed Followed While Issue Standard Was Active No Ye s No No

No PD No PD No PD No PD

Issue Screening (IMC 0612 App. B)

Illustration of Process - Continued

Identified Decisions Decision Potential Change Ye s For Ye sImpacted in Ye s More than Continuation Impacts Applications Way That Minor PRA Impacted Increased Finding Model Risk to Public

No No No

Minor Minor No PD Violation Violation

Issue Screening (IMC 0612 App. B) Minor or MTM (IMC 0612 App. E) Finding Characterization (IMC 0609)

Topics to be Resolved

  • Definition of reasonable doubto Suggested: Minimal amount of data to provide confidence in ability to maintain fidelity in results
  • Public availability of crossSRA peer guidance for information-regional panel guidance and
  • Definition of cornerstone impact
  • Use of accordance with licensee procedurein accordance with the PRA Standard vs. in
  • Data, process, and timelines for SDPs, including clear understanding of how metrics will be calculated NRC PCC SDP Examples

Previously presented during March 18, 2024, Public Meeting.

1) Data not being updated within required time limits
2) Failure to review a plant change for impact on the PRA model
3) Documentation and/or Justification Issue
4) RICT Calculation Error
5) Modeling Control Error Example 1
6) Modeling Control Error Example 2

29 29 NRC Example 1:

==

Description:==

Data not being updated within required time limits.

Performance Deficiency (PD): Failed to perform data update within the period of every 2 refueling outages.

Screening: If left uncorrected, the PD could have the potential to lead to a more significant safety concern or, PD associated with the MS cornerstone of equipment performance and specifically could have affected the availability and reliability of the SSC.

0612 App. E (Examples of Minor Issues): Similar to 8.a, 1.c (program), 3.a (technical error in calculation),

3.h (non-conservative value used), 3.l (used non-conservative data vs. industry data)

Minor if: Recalculation did not adversely affect the cornerstone reliability and unavailability, specifically the condition did not change any risk-informed decisionmaking (RIDM), data ( e.g. MSPI) or other risk-based evaluations, or if the licensee had previously performed a reasonable evaluation justifying the extension.

More than minor (MTM) if: Reasonable doubt (RD) the PD could adversely affect reliability and unavailability prior to recalculation, and/or RD that recalculation could have the potential to adversely change any RIDM in an unfavorable manner or, could have resulted in a non-conservative RIDM outcome.

30 30 NRC Example 2:

==

Description:==

Licensee did not review a plant change for impact on the PRA model. Issue wasnt modeled (or failed to model/PRA group missed modeling a change to the plant).

PD: Licensee failed to perform a review of a change or modification to the plant.

a) Change was not required IAW the PRA Standard, b) Change was a required element IAW the PRA Standard.

c) Change required an update to online risk model, d) Change was significant and required immediate update or required PRA Upgrade.

Screening: If left uncorrected, PD could have the potential to lead to a more significant safety concern or, PD associated with the MS (or IE) cornerstone of equipment performance and could have affected the availability and reliability.

0612 App. E (Exs. of Minor Issues): Similar to 8.c, 8.d, 1.c, 3.a, 3.h, 3.l

Minor if: Review determined the change evaluation did not adversely affect the cornerstone or the reliability and unavailability, specifically the condition was not required IAW the PRA Standard. See (a) above.

MTM if: RD concerning an adverse impact to the cornerstone or the reliability and unavailability prior to evaluation, or there was RD that the missed change/modification could have the potential to change a risk evaluation in an unfavorable manner; or resulted in or could result in a non-conservative RIDM outcome; or if the change required an analysis IAW the PRA Standard or resulted in a change or required a future change to the PRA. See (b), (c), and (d).

31 31 NRC Example 3:

==

Description:==

The licensee failed to provide documentation to adequately demonstrate compliance with maintaining the PRA program. Specifically, the licensee lacked adequate records to support decisions, and/or evaluations of changes, descriptions, and PRA changes, including but not limited to PRA Upgrades and PRA Maintenance, and records of PRA reviews.

PD: Licensee failed to adequately document PRA changes.

Screening: If left uncorrected, PD could have the potential to lead to a more significant safety concern or, PD associated with the MS (or IE) cornerstone of equipment performance and could have affected the availability and reliability.

0612 App. E (Exs. of Minor Issues): Similar to 1.a, 1.c, 3.a, 3.h, 3.l

Minor if: PD did not adversely affect the cornerstone or reliability/unavailability, specifically there was reasonable assurance without significant re-evaluation to conclude change was insignificant to PRA and associated RIDM outcome.

MTM if: PD adversely affected the cornerstone or reliability/unavailability, or RD concerning the reliability/ unavailability prior to updated evaluation, specifically significant effort required to duplicate or reperform the evaluation.

Or documentation was associated with or supported a PRA Upgrade or was a factor in supporting a conclusion regarding a PRA Upgrade or PRA Maintenance or was documentation associated with supporting a Peer Review IAW the PRA Standard.

32 32 NRC Example 4:

==

Description:==

Error identified in a risk informed completion time (RICT) calculation.

PD: Licensee failed to accurately calculate a risk analysis for a RICT.

Screening: If left uncorrected, PD could have the potential to lead to a more significant safety concern or, PD associated with the MS (or IE) cornerstone of equipment performance and could have affected the availability/reliability.

0612 App. E (Exs. of Minor Issues): Similar to 1.a, 1.c, 3.a, 3.h

Minor if: PD did not adversely affect the cornerstone or reliability/unavailability, and did not adversely impact the licensees RIDM, plans, RMAs or schedules. Error was conservative and did not require significant effort to evaluate/update.

MTM if: PD caused RD concerning the reliability/unavailability prior to re-evaluation, or there was RD that error or omission could have potential to change a risk evaluation in an unfavorable manner; or resulted or could result in non-conservative RIDM outcome; including significant decrease in the available RICT calculated backstop.

Or the error significantly affected the RMA time (RMAT) or resulted in the RMAT being passed without knowing.

Or the error in the RICT was non-conservative in nature and/or required significant effort to evaluate or update.

33 33 NRC Example 5:

==

Description:==

PRA did not accurately reflect the as operated Plant. Changed an operating philosophy so the operating equipment train was not necessarily the protected equipment train. Impacts of the operational change on the PRA model were not assessed and therefore the risk assessment tool (RAT) used by operators did not match actual plant conditions resulting in non-conservative risk assessment, impacting baseline CDF calculations and RICT values.

PD: Licensee failed to maintain PCC of the PRA model with the RAT IAW licensee procedures.

Screening: If left uncorrected, PD could have the potential to lead to a more significant safety concern or, PD associated with the MS (or IE) cornerstone of equipment performance and could have affected the availability/reliability.

0612 App. E (Exs. of Minor Issues): Similar to 1.c, 3.a, 3.h

Minor if: PD did not adversely affect cornerstone since contribution to reliability/unavailability was insignificant when compared to initial assessments, and resulting change did not impact the RIDM process and did not require significant changes to risk assessments or plans and higher risk categories were not entered because of any updates.

MTM if: PD caused RD of adverse impact to the cornerstone reliability/unavailability prior to the evaluation, and/or RD that error could potentially or did significantly change risk evaluation in an unfavorable manner; or resulted or could result in non-conservative RIDM outcome; or change required entry into a higher risk category, or caused additional compensatory actions than originally planned.

34 34 NRC Example 6:

==

Description:==

Licensee did not account for the fact that SSCs were required to be in a specific alignment/position for the given plant configuration being analyzed.

PD: Licensee failed to adequately capture and analyze SSCs and their interrelationships for an event..

Screening: If left uncorrected, PD could have the potential to lead to a more significant safety concern or, PD is associated with the IE or MS cornerstone of equipment performance and could have affected availability/reliability of the SSC.

0612 App. E (Exs. of Minor Issues): Similar to 1.c, 3.a, 3.h

Minor if: PD did not adversely affect MS cornerstone since contribution to reliability/unavailability was insignificant, and resulting change did not impact RIDM process, and did not require significant changes to assessments or plans.

No higher risk categories entered because of updates. Review determined error/condition was not required to be analyzed IAW the PRA Standard.

MTM if: PD caused RD concerning adverse impact to the cornerstone or reliability/unavailability prior to evaluation, and/or RD that error could have potential to change risk evaluation in an unfavorable manner; or resulted or could result in a non-conservative RIDM outcome; or if the error or omission should have been a required analysis/input IAW the PRA Standard or required in an unplanned revision or update to the PRA model.

35 35 Discussion and Q&A

36 PRA Configuration Control (PCC)

S D P Meeting x

Public Questions and Comments PRA Configuration Control (PCC)

S D P Meeting x

Closing Remarks PRA Configuration Control (PCC)

S D P Meeting x

Meeting Concluded

Meeting Point of

Contact:

Lundy Pressley Reliability and Risk Analyst NRR / Division of Risk Assessment PRA Oversight Branch Lundy.Pressley@nrc.gov Backup Slides

40 PRA Configuration Control (PCC)

S D P Meeting x

Short Break Resume at 2:00PM Eastern PRA Configuration Control (PCC) Oversight Gap

PRA found acceptable Issuance of SE/LA

PRA Acceptable Changes/Modifications/Data/OpE

T=0 T=Now Assessing the Gap

Plant Modifications

Operating Experience and Data

No Current permanent PRA Maintenance and Upgrades NRC Oversight of PRA Changes

42 OpESS Details

OpESS Objectives:

1. Support inspection activities of PCC programs.
2. Gather information and trends of PCC programs to inform future inspection activities.
3. Verify licensee processes to reasonably ensure PCC activities.

Inspection Guidance:

1. Provide regulatory and operating experience backgrounds.
2. Verify processes and procedures are in place to ensure the PRA program is being maintained to support risk-informed decisions.
3. Verify processes and procedures were completed appropriately to ensure the PRA program was being sufficiently maintained to support past and current risk -informed decisions.
  • Intent would be to revise the OpESS for the subsequent three ROP Cycles based upon observed performance and refocus, as necessary.

43 43

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