ML20213B167

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July 23, 2020, Summary Regarding Second Pre-Application Meeting to Discuss Proposed Technical Specification Task Force-425 License Amendment Request
ML20213B167
Person / Time
Site: Summer South Carolina Electric & Gas Company icon.png
Issue date: 08/13/2020
From: Vaughn Thomas
Plant Licensing Branch II
To:
Thomas, V
References
EPID L-2020-LRM-0049
Download: ML20213B167 (5)


Text

August 13, 2020 LICENSEE: Dominion Energy South Carolina (DESC)

FACILITY: Virgil C. Summer, Unit 1

SUBJECT:

VIRGIL C. SUMMER, UNIT 1 - JULY 23, 2020,

SUMMARY

REGARDING SECOND PRE-APPLICATION MEETING TO DISCUSS PROPOSED TECHNICAL SPECIFICATION TASK FORCE-425 LICENSE AMENDMENT REQUEST (EPID L-2020-LRM-0049)

On July 23, 2020, a Category 1 public teleconference call was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Dominion Energy South Carolina (DESC) regarding Virgil C. Summer, Unit 1 (Summer). This was the second pre-application call to discuss a proposed license amendment request (LAR) to implement risk-informed application for the relocation of specific surveillance frequency requirements to a licensee-controlled program by the implementation of Nuclear Energy Institute (NEI) 04-10, Revision 1 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML071360456),

Risk-Informed Technical Specifications Initiative 5b, Risk-Informed Method for Control of Surveillance Frequencies, and consistent with NRC Technical Specification Task Force (TSTF)

Standard Technical Specifications Change TSTF-425, Revision 3 (ADAMS Accession Package No. ML090850642), Relocate Surveillance Frequencies to Licensee Control - RITSTF

[Risk-Informed Technical Specification Task Force] Initiative 5b.

The public meeting notice and agenda dated July 9, 2020, (ADAMS Accession No. ML20191A186) are available in the NRC Public Meeting website. A list of participants is provided in the Enclosure.

Public Conference Call During the meeting, DESC proposed an approach for addressing the probabilistic risk assessment (PRA) upgrades that have not been peer-reviewed in accordance with applicable standards. DESC proposed to submit an implementation item with the LAR to perform a focused-scope peer review of these PRA upgrades in accordance with applicable standards and resolve in the PRA any new findings identified during this peer review prior to implementation of the surveillance frequency control program (SFCP). The NRC staff stated it is preferred that these PRA upgrades be peer-reviewed before submitting the LAR to the NRC and any resulting finding-level facts and observations (F&Os) dispositioned in the LAR demonstrating the technical acceptability of the PRA in accordance with Regulatory Guide (RG) 1.200, Revision 2, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment for Risk-Informed Activities (ADAMS Accession No. ML090410014).

The NRC noted that an alternative may be an implementation item to perform, prior to SFCP implementation, a peer review of the identified upgrades and close any findings associated with this peer review in accordance with an NRC-accepted process [e.g., RG 1.200, Revision 2, and Appendix X to NEI 05-04/07-12/12-[13], Close-Out of Facts and Observations (F&Os)

(ADAMS Accession No. ML17086A431), as accepted with conditions by NRC letter dated May 3, 2017 (ADAMS Accession No. ML17079A427)]. The NRC staff stated that the LAR should describe the non-peer-reviewed upgrades and provide a justification (e.g., sensitivity study, bounding analysis, qualitative discussion) that the total core damage frequency and large early release frequency is less than the RG 1.174, Revision 3, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis (ADAMS Accession No. ML17317A256), guidelines of 1E-4 and 1E-5 per year, respectively, given these upgrades are not peer-reviewed.

DESC discussed the status of the open F&Os identified from previous peer reviews of the internal events (includes internal floods) and fire PRAs. DESC stated that a large number of these F&Os have been resolved in the PRA but remain open because these resolutions have not been reviewed independently for closure (e.g., Appendix X to NEI 05-04/07-12/12-[13]).

The NRC staffs discussion focused on the large number of internal events F&Os that remain open. NRC staff had reviewed these internal events F&Os as part of its review of the Summer LAR for revisions to the National Fire Protection Association (NFPA) Standard 805 Program (ADAMS Accession No. ML19305A005). However, this effort was reduced because many of these F&Os were not applicable or had an insignificant impact on the fire PRA. For a TSTF-425 license amendment, the review of the open internal events F&Os would be more extensive because each F&O disposition would need to be assessed for appropriateness. As a result, the NRC staff informed the licensee that the level of effort for conducting a TSTF-425 LAR review would increase due to the large number of open internal events F&Os and completing this review within one year may not be feasible. The NRC staff reminded the licensee that F&Os closed in accordance with an NRC-accepted process (e.g., Appendix X to NEI 05-04/07-12/12-

[13], as endorsed by NRC letter dated May 3, 2017) do not need to be submitted in the LAR, thereby, reducing the level of effort required to review the LAR.

DESC indicated that the internal floods PRA was peer-reviewed against American Society of Mechanical Engineers/American Nuclear Society (ASME/ANS) PRA Standard RA-Sb-2013.

The technical adequacy of PRAs used for risk-informed activities is evaluated using RG 1.200, Revision 2, which endorses, with clarifications and qualifications, ASME/ANS PRA Standard RA-Sa-2009. The NRC did not endorse ASME/ANS RA-Sb-2013. The NRC staff indicated that the LAR should explain how the peer review that utilized the 2013 PRA standard meets the technical adequacy guidance in RG 1.200, Revision 2 (e.g., provide the results of a comparison between ASME/ANS RA-Sb-2013 and ASME/ANS RA-Sa-2009, as qualified by RG 1.200, Revision 2).

DESC stated they would need to have an internal discussion on the NRC questions and concerns prior to deciding the schedule for submitting the LAR. No regulatory decisions or commitments were made during the meeting.

/RA/

Vaughn V. Thomas, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos.: 50-395

Enclosure:

List of Attendees cc: Listserv

ML20213B167 OFFICE DORL/LPL2-1/PM DORL/LPL2-1/LA DRA/APLA/BC DORL/LPL2-1/BC DORL/LPL2-1/PM NAME VThomas KGoldstein RPascarelli MMarkley VThomas DATE 07/31/2020 08/10/2020 07/31/2020 08/12/2020 08/13/2020 LIST OF PARTICIPANTS JULY 23, 2020, SECOND PRE-APPLICATION PUBLIC CONFERENCE CALL WITH DOMINION ENERGY SOUTH CAROLINA REGARDING ONE PROPOSED TSTF-425 LICENSE AMENDMENT REQUEST U. S. Nuclear Regulatory Commission Staff Robert Pascarelli, Branch Chief Jennifer Whitman, Branch Chief Shivani Mehta, Reliability and Risk Analyst Jigar Patel, Reliability and Risk Analyst Todd Hilsmeier, Reliability and Risk Analyst Vaughn V. Thomas, Project Manager Licensee Participants Yan Gao, Dominion Energy Nuclear Regulatory Affairs Craig Sly, Dominion Energy Nuclear Regulatory Affairs Bruce Bennett, VCS site licensing Creighton Adsit, Dominion PRA Justin Bouknight, VCS site licensing Robin Haselden, VCS site management Andrew Hall, VCS engineering Eric Rumfelt, Dominion PRA Thomas Yaeger, Dominion PRA Enclosure