ONS-2014-110, Establish the Fukushima Flood Response as the Basis to Govern Flood Mitigation Modifications from Postulated Upstream Dam Failure
| ML14225A540 | |
| Person / Time | |
|---|---|
| Site: | Oconee  (DPR-038, DPR-047, DPR-055) |
| Issue date: | 08/08/2014 |
| From: | Batson S Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| ONS-2014-110 | |
| Download: ML14225A540 (3) | |
Text
Scott L.Batson
~DUKEe DUKE Vice President Oconee Nuclear Station ENERGY, Duke Ener ONOIVP 17800 Rochester Hwy Seneca, SC 29672 ONS-2014-1 10 o: 864.873.3274
- f. 864.873. 4208 Scott.Betson@duke-energy.com August 8, 2014 ATTN: Document Control Desk 10 CFR 50.54(f)
U.S. Nuclear Regulatory Commission Washington, DC 20555 Duke Energy Carolinas, LLC (Duke Energy)
Oconee Nuclear Station, Units 1, 2 and 3 Docket Numbers 50-269, 50-270, 50-287 Renewed License Numbers DPR-38, DPR-47, and DPR-55
Subject:
Establish the Fukushima Flood Response as the Basis to Govern Flood Mitigation Modifications from Postulated Upstream Dam Failure
References:
- 1. NRC Letter; ConfirmatoryAction Letter - Oconee Nuclear Station, Units 1, 2, and 3 Commitments to address external Flooding Concerns,dated June 22, 2010, (ADAMS Accession No. ML101730329)
- 2. NRC Letter; Request for Information Pursuantto Title 10 of the Code of FederalRegulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichiAccident, dated March 12, 2012, (ADAMS Accession No. ML12053A340).
- 3. NRC Letter; Oconee Nuclear Station, Units 1, 2, and 3 - Modifications to Address External Flooding Hazards, dated September 20, 2012, (ADAMS Accession No. ML12219A163)
Flood hazard analysis and mitigation efforts related to postulated upstream dam failures at Oconee Nuclear Station (ONS) have been separately driven by the June 22, 2010 Confirmatory Action Letter (CAL) (Reference 1) and subsequent response to the Fukushima 10 CFR 50.54(f),
Request for Information (Reference 2). A statement made in the NRC's September 20, 2012 letter (Reference 3) acknowledges the interaction of both actions as follows: "The NRC intends to maintain the CAL dated June 22, 2010 active until it can be superseded by regulatory action related to the Fukushima responses." Duke Energy is submitting this letter to establish that the Fukushima 50.54(f) responses now constitutes a updated basis for governing modifications to mitigate a flood from a postulated upstream dam failure.
It is Duke Energy's understanding that the basis for the proposed CAL modifications will be superseded by the Flood Hazard Re-evaluation Report (FHRR) developed as part of the Fukushima 10 CFR 50.54(f) response. Duke Energy is accordingly adjusting its CAL modification strategy to focus on a FHRR based modification strategy. Final approval of the FHRR will allow the CAL flooding basis to be replaced by the Fukushima flood analysis of upstream dam failures. Duke Energy will then update its CAL response with the new mitigation strategy and the corresponding modifications.
ONS-2014-1 10 August 8, 2014 Page 2 of 3 Duke Energy remains dedicated to completing upstream dam failure mitigation modifications based on the approved FHRR by June 2016. All CAL compensatory measures will remain in effect until regulatory action allows their suspension.
A separate point of clarification is needed regarding the NRC's September 20, 2012 letter. The letter states that the NRC staff is committed to have licensees implement plant modifications brought about by Fukushima initiatives by the end of 2016. It is Duke Energy's understanding that this statement applies to Fukushima modifications enacted by NRC Orders, however, Duke Energy recognizes that the ONS modifications related to mitigation of flooding from an upstream dam failure are based on a June 2016 timeframe. The point to be clarified is that Fukushima 50.54(f) responses related to ONS flood sources other than an upstream dam failure (e.g.,
precipitation events), will be completed commensurate with the 50.54(f) timelines and may extend beyond 2016.
In summary, based on the recognition that the flood basis in the FHRR for an upstream dam failure will supplant the 2010 CAL flood basis, the related flood mitigation modifications for ONS are now based on the FHRR rather than the CAL. Duke Energy intends to revise its CAL response once a regulatory position has been reached on the FHRR. Duke Energy is resolved to complete, by a target date of June 2016, modifications to mitigate a flood based on the FHRR upstream dam failure. The compensatory actions committed to in the CAL will remain in place until regulatory action allows their suspension. Finally, Fukushima 50.54(f) responses related to other flood sources, such as precipitation events, may extend beyond 2016.
This letter contains no new regulatory commitments.
Should you have any questions or require additional information, please contact David Haile of the ONS Regulatory Affairs Group, at (864) 873-4742.
Sincerely, Scott L. Batson Vice President Oconee Nuclear Station
- ONS-2014-110 August 8, 2014 Page 3 of 3 cc:
Mr. Victor McCree, Regional Administrator U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 Mr. Daniel Dorman, (Acting) Director, Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission One White Flint North, 11555 Rockville Pike, M/S 13-H16M Rockville, MD 20852-2738 Mr. John P. Boska, Project Manager (by electronic distribution)
U.S. Nuclear Regulatory Commission One White Flint North, M/S O-8G9A 11555 Rockville Pike Rockville, MD 20852-2746 Mr. James R. Hall, Project Manager (ONS)
(by electronic mail only)
U.S. Nuclear Regulatory Commission 11555 Rockville Pike, M/S O-8G9A Rockville, MD Mr. Eddy Crowe NRC Senior Resident Inspector Oconee Nuclear Station