Letter Sequence RAI |
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MONTHYEARNMP2L2706, License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b2019-10-31031 October 2019
License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b
Project stage: Request
ML19339E8542019-12-0505 December 2019
Supplemental Information Needed for Acceptance of Requested Licensing Action Adoption of Risk-Informed Completion Times
Project stage: Acceptance Review
NMP2L2718, Supplemental Information No.1 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22019-12-12012 December 2019
Supplemental Information No.1 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2
Project stage: Supplement
ML20023B1622020-01-21021 January 2020
Acceptance of Requested Licensing Action Use of Risk-Informed Completion Times
Project stage: Acceptance Review
ML20037B6542020-02-0606 February 2020
Audit Plan Regarding License Amendment Request to Implement Risk-Informed Extended Completion Times 50-410 (L-2019-LLA-0234)
Project stage: Other
ML20094J1562020-04-22022 April 2020
Audit Plan Supplement in Support of Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times
Project stage: Other
ML20213A9352020-07-30030 July 2020
Request for Additional Information Review of License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times
Project stage: RAI
NMP2L2739, Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22020-08-28028 August 2020
Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2
Project stage: Request
ML20246G6362020-09-0202 September 2020
Request for Additonal Information to Support Review of License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times
Project stage: Approval
ML20273A2372020-09-28028 September 2020
Request for Additional Information Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times
Project stage: RAI
ML20272A2802020-09-28028 September 2020
Withdrawal and Replacement of Request for Additional Information to Support Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times
Project stage: RAI
ML20248H5192020-09-28028 September 2020
Changes to Draft Request for Additional Information Regarding Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times
Project stage: Draft RAI
NMP2L2745, Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22020-10-0202 October 2020
Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2
Project stage: Request
NMP2L2746, Supplemental Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22020-10-0202 October 2020
Supplemental Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2
Project stage: Supplement
NMP2L2749, Responses to Request for Additional Information Questions 17 and 26 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Rev. 22020-10-22022 October 2020
Responses to Request for Additional Information Questions 17 and 26 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Rev. 2
Project stage: Response to RAI
ML20351A1642020-12-15015 December 2020
Request for Additional Information Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times
Project stage: RAI
NMP2L2754, Responses to Request for Additional Information Questions 27 and 28 to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22021-01-0707 January 2021
Responses to Request for Additional Information Questions 27 and 28 to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2
Project stage: Response to RAI
ML21082A2212021-04-29029 April 2021
Issuance of Amendment No. 186, Adoption of TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4B
Project stage: Approval
2020-02-06
[Table View] |
Text
From:
Marshall, Michael To:
[Licensee] Ron Reynolds (Exelon)
Cc:
Danna, James
Subject:
NINE MILE POINT NUCLEAR STATION, UNIT 2 - REQUEST FOR ADDITIONAL INFORMATION RE: REVIEW OF LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT RISK-INFORMED COMPLETION TIMES (EPID L-2019-LLA-0234)
Date:
Monday, September 28, 2020 3:09:00 PM Hello Ron:
B letter dated October 31, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19304B653), as supplemented by letters dated December 12, 2019, and August 28, 2020 (ADAMS Accession Nos. ML19346F427 and ML20241A044, respectively), Exelon Generation Company, LLC (Exelon, the licensee) requested that the U.S. Nuclear Regulatory Commission (NRC) amend the Appendix A, Technical Specifications, of Renewed Facility Operating License No. NPF-69 for Nine Mile Point Nuclear Station, Unit 2. Exelons proposed license amendment request (LAR) would revise technical specification requirements to permit the use of risk-informed completion times for actions to be taken when limiting conditions for operation are not met. The proposed changes are based on Technical Specifications Task Force Traveler, TSTF-505, Revision 2, Provide Risk Informed Extended Completion Times - RITSTF Initiative 4b, dated July 2, 2018 (ADAMS Accession No.ML18269A041).
The U.S. Nuclear Regulatory Commission staff has reviewed the information provided in the LAR and has determined that additional information is needed to complete its review.
The request for additional information was discussed with you on September 25, 2020, and it was agreed that your response would be provided within 30 days of the date of this email.
The RAI listed below is in addition to RAIs 1 to 5 and RAIs 6 to 25 sent to you in emails dated July 30, 2020 and September 2, 2020 (ADAMS Accession Nos. ML20213A935 and ML20246G636).
RAI 26
Section 2.3.1, Item 7, of Nuclear Energy Institute (NEI) 06-09, Revision 0-A (ADAMS Accession No. ML12286A322), states, The impact of other external events risks shall be addressed in the RRMTS [Risk-Managed Technical Specifications] program, and explains that one method to do this is by performing a reasonable bounding analysis and applying it along with the internal events risk contribution in calculating the configuration risk and the associated RICT [riskinformed completion time] RICT. The NRC staffs safety evaluation for NEI 06-09 (ADAMS Accession No. ML071200238) states, Where PRA [probabilistic risk assessment] models are not available, conservative or bounding analyses may be performed to quantify the risk impact and support the calculation of the RICT.
LAR Enclosure 4, Section 3, states that to determine a bounding seismic core damage frequency, the peak ground acceleration hazard curve for the 50th percentile high confidence of low probability of failure (HCLPF) value of 0.42g was used from its individual plant evaluation of external events (IPEEE) seismic margins analysis (SMA). (Note: The SMA HCLPF value of 0.5g is the 84th percentile value). The IPEEE HCLPF value of 0.42g was used rather than the HCLPF value of 0.23g in Table C-2 of Results of Safety/Risk Assessment of Generic Issue 199 (GI-199), Implications of Updated Probabilistic Seismic
Hazard Estimates in Central and Eastern United States on Existing Plants (ADAMS Accession No. ML100270582). The LAR states that related sensitivity studies were performed on the impact to risk of changing the ground motion frequencies and seismic hazard intervals. The LAR does not describe those sensitivity studies results or how insights from those studies were used. The exception to this is that sensitivity study results are presented in LAR Table E4-4 to justify the defined seismic hazard interval for the highest seismic bin, the %G8 interval (i.e., seismic hazard internal > 1.5g).
a) Explain why the IPEEE HCLPF value of 0.42g was used rather than the HCLPF value of 0.23g in GI-199 and why it is acceptable for this application.
b) Describe the cited sensitivity studies and results.
c) Explain how insights from the sensitivity studies were used to select to a bounding ground motion and to define the seismic hazard intervals.
Best Regards, Michael L. Marshall, Jr.
Senior Project Manager
Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
301-415-2871
Docket No.05-410
