GNRO-2018/00055, Response to Request for Additional Information for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a ...

Response to Request for Additional Information for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a ...

ML18337A136
Person / Time
Site:	Grand Gulf
Issue date:	11/30/2018
From:	Emily Larson Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GNRO-2018/00055
Download: ML18337A136 (9)

Text

Entergy Operations, Inc.

P.O. Box 756 Port Gibson, Mississippi 39150 Eric A. Larson Site Vice Presidenf Grand Gulf Nuclear Station Tel 601-437-7500 10 CFR 50.90 GNR0-2018/00055 November 30, 2018 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D. C. 20555

SUBJECT:

Response to Request for Additional Information for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program (TSTF-425)

Grand Gulf Nuclear Statiot), Unit 1 Docket No. 50-416 Renewed License No. NPF-29

REFERENCES:

1. Letter from E.A. Larson (Entergy) to Document Control Desk (NRC),

"Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program (TSTF-425)," April 12, 2018 (NRC Agencywide Documents Access and Management System (ADAMS) Accession No. ML181028445)

2. Letter from E.A. Larson (Entergy) to Document Control Desk (NRC),

"Supplement to Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program (TSTF-425)," June 7, 2018 (NRC ADAMS Accession No. ML18158A514) .

3. Electronic mail from L. M. Regner (NRC) to D. A. Neve and J.

Schrage (Entergy),

Subject:

Final Request for Additional Information -

• TSTF-425 (L-2018-LLA-0106), October 31 2018, 3:10 PM

Dear Sir or Madam:

By letter dated April 12, 2018 (Reference 1), as supp,lemented by letter dated June 7, 2018 (Reference 2), Entergy Operations, Inc. (Entergy) requested a license amendment to modify the Grand Gulf Nuclear Station, Unit 1 technical specifications by relocating specific surveillance frequencies to a licensee-controlled program with the implementation of Nuclear Energy Institute 04-10, "Risk-Informed Technical Specification Initiative Sb, Risk-Informed Method for Control of Surveillance Frequencies." By correspondence from Lisa Regner (NRC) to Douglas

GNR0-2018/00055 Page 2 of 3 Neve and John Schrage (Entergy) dated October 31, 2018, (Reference 3), the NRC provided a request for additional inform?tion (RAI) in support of the TSTF-425 license amendment request.

This letter provides Entergy responses to the RAI. The information provided herein does not change the intent or the justification for the requested license amendment (Reference 1) and does not alter the conclusion that the proposed license amendment does not involve a significant hazards consideration as published in Federal Register 74 FR 32000 dated July 6, 2009.

No new regulatory commitments are made in this submittal.

In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," a copy of this application, with attachments, is being provided to designated State of Mississippi Official.

If you should have any questions regarding this submittal, please contact Douglas A. Neve, Manager, .Regulatory Assurance, at 601.437.2103.

I declare under penalty of p~rjury that the foregoing is true and correct. Executed on 30th day of November 2018.

Sincerely, Eric A. Larson EAUgwe

Attachment:

Response to Request for Additional Information Supporting License Amendment Request to Relocate Specific Surveillance Frequency Requirements cc: with Attachment Ms. Lisa Regner U.S. Nuclear Regulatory Commission Mail Stop OWFN 8 81 ,

Rockville, MD 20852-2738 Mr. Siva Lingam U.S. Nuclear Regulatory Commission Mail Stop OWFN 8 81 Rockville, MD 20852-2738 Dr. Thomas Dobbs, M.D., M.P.H State Health Officer Mississippi Department of Health

G NR0-2018/00055 Page 3 of 3 P.O. Box 1700 Jackson, MS 39215-1700 Email: Thomas.dobbs@msdh.ms.gov cc: without Attachment Mr. Kriss Kennedy Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, TX 76011-4511 N RC Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150

ATTACHMENT to GNR0-2018/00055 Response to Request for*Additional Information Supporting ~icense Amendment Request to Relocate Specific Surveillance Frequency Requirements

Attachment GNRO 2018/00055 Page 1 of 5

1. Summary Description By letter dated April 12, 2018 (Reference 1) as supplemented by letter dated June 7, 2018 (Reference 2), Entergy Operations, Inc. (Entergy) requested a license amendment to modify the Grand Gulf Nuclear Station, Unit 1 (GGNS) technical 'specifications by relocating specific surveillance frequencies to a licensee-controlled program with the implementation of Nuclear Energy Institute 04-10, "Risk-Informed Technical Specification Initiative 5b, Risk-Informed Method for Control of Surveillance Frequencies." By correspondence from Lisa Regner (NRC) to Douglas Neve and John Schrage (Entergy) dated October 31, 2018, (Reference 3), the NRC provided a request for additional information (RAI) in support of the Technical Specifications Task Force (TSTF) traveler TSTF-425 lice*nse amendment request (LAA). The following provides the Entergy responses to the RAI.

2. NRC Staff Request for Additional Information RAl-1:

In letter dated June 7, 2018, Entergy provided a supplement (U.S. Nuclear Regulatory Commission (NRC) Agencywide Documents Access and Management System Accession No. ML18158A514) in response to NRC Acceptance Review request for additional information. This supplement provides a list of facts and observations (F&Os) for the Grand Gulf Nuclear Station (GGNS) Internal Events Probabilistic Risk Assessment (PRA) Model from the 2015 full-scope industry peer review that were closed by an independent assessment conducted August 23-31, 2017.

F&O 4-14 addresses the bases for not including prior plant failures into plant. specific data.

The resolution states" ... all failures included in the PRA must have occurred during the time frame for the PRA update (Sept 1, 2006 through Aug 31, 2010) and must meet the definition of a PRA functional failure." Provide the justification for only including plant failures that have occurred during the time frame for PRA update or revise the plant-specific data consistent with uniformity in design, operational practices, and experience.

Entergy Response to RAl-1 :

Please note that the plant-specific data collection time frame specified in F&O 4-14 of the GGNS LAR supplement (Reference 2) is September 1, 2006 through August 31, 2012, not 2010. As stated in Section 3.2.2 of the GGNS PRA Technical Adequacy Report (Attachment 2 of Reference 1), the PRA model was updated to support resolutions of the 2015 peer review findings, which included F&O 4-14. This model update was approved in 2017 following completion of the independent assessment. Use of plant failures that occurred during the six-year time frame of the PRA update was based on the following:

• The data collection period ending in August 2012 coincided with the time frame of update to the data analysis for the PRA revision.

• Regarding the data collection period indicated in F&O 4-14, the peer reviewer suggested being consistent when referencing the plant-specific data timeframe; however, the peer reviewer noted that the time frame selected was appropriate and correctly used in the model. Therefore, additional data collection was not warranted.

Attachment GNRO 2018/00055 Page 2 of 5

• The dpta is representative of multiple refueling cycles, which is also representative of operating practices for the period. ,

• Use of data prior to September 1, 2006 would result in a more substantial overlap with the generic data reference used for the update (i.e., the 2010 update to the component reliability data sheets of NUREG/CR-6928, "Industry-Average Performance for Components and Initiating Events at U.S. Commercial Nuclear Power Plants" (Reference 4), which contains data collected between 1998 and 2010). Extensive overlap between the plant-specific data and the generic data source used for Bayesian update is avoided to minimize double-counting of GGNS failure events that appear in both the generic and plant-specific data set.

To ensure the six-year plant-specific data provided in the PRA model continues to adequately represent the uniformity in plant design, operational practice, and experience, a sensitivity study of plant failure data since August 2012 will be performed to determine if a further PRA update is needed. Entergy will provide the results of this sensitivity study by late first quarter 2019.

RAl-2:

- Section 3.1 of the GGNS license amendment request (LAR) states "GGNS does not currently have a Fire PRA model developed in accordance with NUREG/CR-6850. A bounding fire risk evaluation, based on information from the IPEEE and other available insights for fire risk will be performed for STI changes ... " Memo from S. Rosenberg titled "Comments on the Technical Specifications Task Force Letter 09 titled 'Clarification on Information Needed from Licensees Adopting TSTF-425, Revision 3, Relocate Surveillance Frequencies to Licensee Control - RITSTF Initiative 58"' dated December 15, 2015 (ADAMS: ML15280A318) Enclosure 1 Page 3 provides clarification that licensees using qualitative or bounding methods to evaluate external events, fire risk, or shutdown events in accordance with NEI 04-10, Revision 1, should identify that fact in their submittal and summarize the method. Technical Specifications Task Force (TSTF) 14-09 titled "Clarification of Information Needed from Licensees Adopting TSTF-425, Revision 3" dated April 21, 2016 (ADAMS: ML18051A833) Resolution #1 states "Licensees using qualitative or bounding methods to evaluate ~xternal events, fire risk, or shutdown events in accordance with NEI 04-10, Revision 1, will identify that fact in their submittal and summarize the method." In addition, for bounding methods, TSTF 14-09 provides a footnote that specifies the analysis should incorporate relevant operating experience and additional risk insights obtained since the IPEEE study, in the context of the current plant configuration and operation.

As specified in TSTF-14-09, provide a summary of the method employed for evaluating fire risk for SFCP and provide a description of updates to the fire I PEEE evaluation based on relevant operating experience and additional risk insights obtained since the study was conducted.

Entergy Response to RAl-2:

A fire probabilistic risk assessment (PRA) was developed for GGNS in 2005 to examine fire risks relative to the Individual Plant Examination for External Events (IPEEE). As stated in Section 3.1 of the GGNS LAR (Reference 1) and restated in RAl-2 herein, the GGNS fire

Attachment GNRO 2018/00055 Page 3 of 5 PRA model was not developed in accordance with NUREG/CR-6850, "EPRI/NRC-RES Fire PRA Methodology for Nuclear Power Facilities" (Reference 5). Analyses performed for the I PEEE and the fire PRA do not provide quantitative fire risk information that can be directly compared to the internal events PRA model on a quantitative basis due to conservatisms.

The GGNS fire PRA evaluation was completed in August 2005 and has not been updated since the evaluation was completed. Fire zones provided in the I PEEE evaluation also have not been updated to keep in step with plant changes.

The GGNS plant procedure used to assess risk for maintenance activities has been updated, as necessary, to incorporate operational experience with respect to implementing fire risk management actions (RMAs). Specifically, guidance to qualitatively assess risk of fire zones and provide explicit RMAs to mitigate fire risk was incorporated into this procedure in November 2013, based on the Revision 4A to NUMARC 93-01, "Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants" (Reference 6). NRC Regulatory Guide 1.160, Revision 3 (Reference 7) endorses the use of Revision 4A of NUMARC 93-01.

When assessing fire risk, a bounding assessment is performed considering the qualitative aspects of the risk, including the impact of fire initiators in applicable fire zones when one or more structure, system, or component (SSC) in scope is identified as unavailable. Entergy currently offsets fire risk configurations by implementing RMAs in accordance with the plant risk assessment for maintenance activities procedure to minimize the likelihood of a fire.

The equipment-out-of-service (EOOS) monitor does not calculate the impact on risk due to fire but is used to assess fire mitigation risk and indicates if there is a safe shutdown analysis (SSA) risk mitigation success path for risk significant fire areas.

For the Surveillance Frequency Control Program (SFCP), Entergy plans to employ the bounding qualitative analysis for surveillance frequency changes associated with SSCs evaluated in the fire PRA, which includes appropriate RMAs. A detailed qualitative analysis is performed if the affected SSC is not modeled or included in the EOOS monitor. The bounding qualitative method of determining fire risk is sufficient for implementing surveillance frequency changes in accordance with the SFCP. Implementation of RMAs provides: increased risk awareness of appropriate plant personnel; more rigorous planning and control of the activity; and measures to control the duration and magnitude of the increased risk.

RAl-3:

The NEI 04-10, Section 3.0, "Key Safety Principles" outlines the key safety principles to be addressed in risk-informed change applications. The fifth principle addresses monitoring changes using performance monitoring strategies. The LAR provides a brief statement in Section 2.1, "Surveillance Frequency Change Process" that indicates the integrated decision making panel is responsible for reviewing the performance monitoring results. Describe how GGNS intends to implement performance monitoring strategies to monitor changes to surveillance frequencies.

Entergy Response to RAl-3:

Entergy currently utilizes fleet procedures for monitoring the effects of changes to surveillance frequencies in accordance with the SFCP for those plants within the Entergy

Attachment

• GNRO 2018/00055 Page 4 of 5 fleet that have already implemented the program in accordance with their technical specifications and NEI 04-10, Revision 1. This monitoring procedure will be utilized to implement performance monitoring strategies of the GGNS SFCP. GGNS will implement performance monitoring strategies to monitor changes to surveillance frequencies consistent with the requirements of NEI 04-10, Revision 1, as required by proposed TS 5.5.6, "Surveillance Frequency Control Program," in the GGNS LAR (Reference 1). The perfor~ance monitoring strategies include the following:

• Confirmation that no failure mechanisms that are related to the revised STI become important enough to1 alter the failure rates assumed in the justification of the program changes.

• Performance monitoring ensures adequate component capability (i.e., margin) exists, relative to design-basis conditions, so that component operating characteristics do not result in reaching a point of insufficient margin before the next scheduled test.

• Component or train level monitoring is expected for high safety significant structures, systems, and components as defined by the GGNS Maintenance Rule program

• In general, performance will be monitored per the monitoring requirements of the Maintenance Rule program. However, additional monitoring unique to a revised STI may be specified.

• The output of the perfqrmance monitoring will be periodically re-assessed, and appropriate adjustments made to the surveillance frequencies, if needed.

3.

References:

1. Letter from E.A. Larson (Entergy) to Document Control Desk (NRC), "Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program (TSTF-425)," April 12, 2018 (NRC Agencywide*Documents Access and Management System (ADAMS) Accession No. ML181028445).

2. Letter from E.A. Larson (Entergy) to Document Control Desk (NRC), "Supplement to

• Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program (TSTF-425)," June 7, 2018 (NRC ADAMS Accession No. ML18158A514).

\

3. Electronic mail from L. M. Regner (NRC) to D. A. Neve and J. Schrage (Entergy),

Subject:

Final Request for Additional Information -TSTF-425 (L-2018-LLA-0106),

October 31 2018, 3:10 PM.

4. Component Reliability 2010 Update to NRC NUREG/CR-6928, "Industry-Average Performance for Components and Initiating Events at U.S. Commercial Nuclear Power Plants," Idaho National Laboratory, September 2012 (Website:

https://nrcoe. inl .gov/resultsdb/Avg Perf/).

5. NRC NUREG/CR-6850, "EPRI/NRC-RES Fire PRA Methodology for Nuclear Power Facilities," Volumes 1 and 2, Electric Power Research Institute, September 2005.

Attachment GNRO 2018/00055 Page 5 of 5

6. Nuclear Energy Institute NU MARC 93-01, "Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants," Revision 4A, April 2011 (NRC ADAMS Accession No. ML11116A198).

7. NRC Regulatory Guide 1.160, "Monitoring the Effectiveness of Maintenance at Nuclear Power Plants," Revision 3, May 2012 (NRC ADAMS Accession No. ML113610098).