ML15314A108
| ML15314A108 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 11/20/2015 |
| From: | Victor Hall Japan Lessons-Learned Division |
| To: | Diya F Ameren Missouri |
| Marshall, Michael, NRR/JLD 415-2871 | |
| References | |
| CAC MF1096 | |
| Download: ML15314A108 (3) | |
Text
Mr. Fadi Diya Senior Vice President and Chief Nuclear Officer Ameren Missouri Callaway Plant P.O. Box 620 Fulton, MO 65251 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 20, 2015
SUBJECT:
CALLAWAY PLANT, UNIT 1 - MITIGATING STRATEGIES ASSESSMENT WITH RESPECT TO THE REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) INFORMATION REQUEST-FLOOD-CAUSING MECHANISM REEVALUATION (CAC NO. MF1096)
Dear Mr. Diya:
The purpose of this letter is to describe the next steps following the review of the reevaluated flood hazard as directed by the Commission. Specifically, this !etter addresses the next steps associated with the mitigation strategies assessment (MSA) with respect to the reevaluated flood hazard.
By letter dated March 12, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12053A340), the U.S. Nuclear Regulatory Commission (NRC) issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f) (hereafter referred to as the 50.54(f) letter). The request was issued as part of implementing lessons learned from the accident at the Fukushima Dai-ich1 nuclear power plant. to the 50.54(f) letter requested licensees to reevaluate flood-causing mechanisms using present-day methodologies and guidance. By letter dated March 8, 2013 (ADAMS Accession No. ML13071A315), Union Electric Company (the licensee), doing business as Ameren Missouri, responded to this request for Callaway Plant, Unit 1 (Callaway). This response was supplemented by letter dated February 27, 2014 (ADAMS Accession No. ML14059A232). By letter dated October 29, 2014 (ADAMS Accession No. ML14290A532), the NRC staff transmitted to you its staff assessment of the information provided in the above mentioned letters. The NRC staff has completed its review of t~e information provided The current flood hazard reevaluation approach is aescribed in NRC letter dated September 1, 2015 (ADAMS Accession No. ML15174A257}, concerning the coordination of requests for information regarding flooding hazard reevaluations and mitigating strntegies for beyond-design-basis external events. This letter describes the changes in tt1e NRC's approach to the flood hazard reevaluations that were approved by the Commission *in'its Staff Requirements Memorandum (ADAMS Accession No. ML15209A682) to COMSECY-15-0019 (ADAMS Accession No. ML15153A104) that described the NRC's mitigating strategies and flooding hazard reevaluation action plan.
As described in the staff assessment, the NRC staff confirmed that the licensee responded appropriately to Enclosure 2 of the 50.54(f) letter. The NRC staff confirmed that the reevaluated hazard results for each reevaluated flood-causing mechanism are bounded by the current design-basis flood hazard and an integrated assessment or a focused evaluation, is not necessary for Callaway. The NRC staff has no additional information needs at this time with respect to Enclosure 2 of the 50.54(f) letter.
The September 1, 2015, letter described expectations for sites to perform an assessment of their mitigation strategies with respect to the reevaluated hazard. The licensee is expected to perform an MSA for Callaway. The Nuclear Energy Institute (NEI) guidance document NEI 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised. This revision will include a methodology to perform an MSA with respect to the reevaluated flood hazards. The NRC staff has concluded that the licensee's reevaluated hazard information is suitable for the assessment of mitigation strategies developed in response to Order EA-12-049 (i.e., defines the mitigation strategies flood hazard information described in the revised NEI 12-06 guidance currently being finalized by the industry and NRC staff).
If you have any questions, please contact me at (301) 415-2915 or e-mail at Victor.Hall@nrc.gov.
Docket No. 50-483 cc: Distribution via Listserv Sincerely,
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Victor Hall, Senior Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation
- via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/JHMB/PM NRR/JLD/LA NAME MMarshall VHall Slent DATE 11/10/2015 11/13/2015 11/16/2015 OFFICE OGC NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME EWilliamson MShams VHall(TGovan for)
DATE 11/19/2015 11/20/2015 11/20/2015