ML16161A477

Oyster Creek Nuclear Generating Station - Staff Review of Mitigation Strategies Assessment Report of the Impact of the Reevaluated Seismic Hazard Developed in Response to the March 12, 2012, 50.54(f) Letter

ML16161A477
Person / Time
Site:	Oyster Creek
Issue date:	06/16/2016
From:	Vega F G Japan Lessons-Learned Division
To:	Bryan Hanson Exelon Generation Co
References
CAC MF7766
Download: ML16161A477 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON , D.C. 20555-0001 Mr. Bryan C. Hanson President and Chief Nuclear Officer Exelon Generation Company , LLC 4300 Winfield Road Warrenville , IL 60555 June 16 , 2016

SUBJECT:

OYSTER CREEK NUCLEAR GENERATING STATION -STAFF REVIEW OF MITIGATION STRATEGIES ASSESSMENT REPORT OF THE IMPACT OF THE REEVALUATED SEISMIC HAZARD DEVELOPED IN RESPONSE TO THE MARCH 12 , 2012 , 50.54(f) LETTER (CAC NO. MF7766)

Dear Mr. Hanson:

The purpose of this letter is to provide the U.S. Nuclear Regulatory Commission's (NRC) assessment of the seismic hazard mitigation strategies assessment (MSA}, as described in the May 25 , 2016 , letter (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 16147A150), submitted by Exelon Generation Company , LLC , (Exelon , the licensee) for Oyster Creek Nuclear Generating Station (Oyster Creek). The MSA confirms that the licensee has adequately addressed the reevaluated seismic hazard within its mitigating strategies for beyond-design-basis external events. BACKGROUND By letter dated March 12 , 2012 (ADAMS Accession No. ML 12053A340}, the NRC issued a request for information pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Section 50.54(f) (hereafter referred to as the 50.54(f) letter). The 50.54(f) letter was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 1 to the 50.54(f) letter requested licensees reevaluate the seismic hazard using present-day methodologies and guidance.

Concurrent with the reevaluation of seismic hazards , the NRC issued Order EA-12-049 , "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 12054A736). The order requires holders of operating power reactor licenses and construction permits issued under 10 CFR Part 50 to develop , implement, and maintain guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling following a beyond-design-basis external event. By letter dated March 31 , 2014 (ADAMS Accession No. ML 14090A241}, the licensee provided its reevaluated seismic hazard for Oyster Creek in response to the 50.54(f) letter.

B. Hanson On December 10 , 2015 (ADAMS Accession No. ML 16005A621), the Nuclear Energy Institute (NEI) submitted Revision 2 to NEI 12-06 , including guidance for mitigating strategies assessments regarding reevaluated hazard information. The NRC subsequently endorsed NEI 12-06 , Revision 2 , with exceptions , clarifications , and additions in , Japan Lessons-Learned Division (JLD) interim staff guidance (ISG) JLD-ISG-2012-01 , Revision 1, " Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 15357A163).

MITIGATION STRATEGIES ASSESSMENT By letter dated February 17 , 2016 (ADAMS Accession No. ML 15350A353), the NRC staff documented its review of the licensee's reevaluated seismic hazard, also referred to as the mitigating strategies seismic hazard information. The staff stated that the licensee's reevaluated seismic hazard is bounded by the original design-basis (i.e., Housner-shape design spectrum) at frequencies above 1 Hertz (Hz). In addition , the staff concluded that the Ground Motion Response Spectrum determined by the licensee adequately characterizes the reevaluated hazard for the Oyster Creek site. The licensee stated that the Oyster Creek MSA was performed consistent with NEI 12-06 , Revision 2. Appendix H of NEI 12-06 , Revision 2 , describes acceptable methods for demonstrating that the reevaluated seismic hazard is addressed within the Oyster Creek mitigating strategies for beyond-design-basis external events. The NRC staff confirmed that the licensee's seismic hazard MSA is consistent with the guidance in Appendix H.4.1 of NEI 12-06 , Rev i sion 2 , as endorsed , by JLD-ISG-2012-01 , Revision 1. Therefore , the methodology used by the licensee is appropriate to perform an assessment of the mitigation strategies that addresses the reevaluated seismic hazard. The NRC staff has reviewed the seismic hazard MSA for Oyster Creek. The NRC staff concludes that sufficient information has been provided to demonstrate that the licensee's plans for the development and implementation of guidance and strategies under Order EA-12-049 appropriately address the reevaluated seismic hazard information stemming from the 50.54(f) letter.

B. Hanson If you have any questions, please contact me at (301) 415-1617 or via e-mail at Frankie.Vega@nrc

.gov. Docket No. 50-219 cc: Distribution via Listserv Frankie Vega, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation B. Hanson If you have any questions, please contact me at (301) 415-1617 or via e-mail at Frankie.Vega@nrc.gov. Docket No. 50-219 cc: Distribution via Listserv DISTRIBUTION:

PUBLIC JHMB R/F RidsNrrDorlLPL 1-2 Resource RidsNrrPMOysterCreek Resource RidsNrrLASLent Resource RidsAcrsAcnw_MailCTR Resource Sincerely , IRA/ Frankie Vega, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation FVega , NRR BTitus , NRR EBowman , NRR MShams, NRR ADAMS Accession No. ML 16161A477

• via e-mail OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME FVega Slent MShams FVega DATE 06/14/2016 06/10/2016 06/16/2016 06/16/2016 OFFICIAL RECORD COPY