ML13066A421
| ML13066A421 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/10/2010 |
| From: | Jeffrey Mitman Office of Nuclear Reactor Regulation |
| To: | Ferrante F Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2012-0325 | |
| Download: ML13066A421 (2) | |
Text
Mitman, Jeffrey From:
Mitman, Jeffrey Sent:
Thursday, June 10, 2010 10:00 AM To:
Ferrante, Fernando; Circle, Jeff
Subject:
FW:pU*iSecurity-Related Information - Update on Oconee External Flooding Issue Attachments:
Corfmr Briefing on Oconee External Flooding Event (2).ppt FYI From: Khanna, Meena Sent: Wednesday, June 09, 2010 5:33 PM To: Kulesa, Gloria; James, Lois; Bartley, Jonathan; Shoop, Undine; Coleman, Neil; Wescott, Rex; Mitman, Jeffrey; Uribe, Juan; Sexton, Kimberly; Simon, Marcia Cc: Wilson, George; Stang, John; Hiland, Patrick; Skeen, David; Guitter, Joseph; Howe, Allen; Cunningham, Mark; Lee, Samson; Scot.Catherine; Hilton, Nick
Subject:
0YO/Security-Related Information - Update on Oconee External Flooding Issue Provided below is an update on the Oconee external flooding issue:
The staff issued a request for additional information (RAI) on January 29, 2010, whereby the staff requested that Duke provide information so that the staff could determine if the analyses performed to date will demonstrate, for the entire Jocassee earthen works, that ONS will be adequately protected from external flooding events. There are two different flooding scenarios that need to be evaluated by the licensee. The first flooding scenario is a result from a slow failure of the Keowee dam and the resultant plant flooding is dominated by a breach of the intake dike and a backup of water from the Keowee tailrace. The second flooding scenario will be from a quick failure of the Keowee dam to evaluate the effects of the backup of water from the Keowee tailrace as the dominant effect of the flooding at the plant.
By letter dated March 5, 2010, Duke submitted a preliminary set of responses to the staff's questions. The final set of responses is scheduled to be submitted by Duke by June 30, 2010.
By letter dated January 15, 2010, Duke submitted a letter to the NRC which provided its interim compensatory measures (ICMs) to ensure that ONS will be adequately protected from external flooding events until the final mitigating strategies have been implemented and all site modifications have been completed.
DRA staff estimated generic dam failure rate for large rock-filled dams to be 2.8E-4/dam-year. DRA's Generic Failure Rate Evaluation for the Jocassee Dam is available in ADAMs (ML100760108).
DE has drafted a supplement to the technical basis for allowing the Oconee Nuclear Station to Remain in Operation through November 2010. Comments from DRA are being incorporated. Plan to issue by June 11,2010.
DE is finalizing the Oconee Adequate Protection Backfit Documented Evaluation. Comments from Region II and OGC are being incorporated. Plan to finalize the draft document by June 11, 2010.
On May 25, 2010, DE and DORL briefed Commissioner Apostolakis on the Oconee External Flooding Issue (presentation slides are attached).
On May 27, 2010, Duke met with NRR management and staff to discuss the status of their implementation of the ICMs, the Order process, and path forward. Duke discussed the wording of their commitments associated with the ICMs. After the discussion, the staff and the licensee agreed on the appropriate wording of the ICMs. Duke indicated that approximately 75% of the ICMs had already been implemented, 1
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which included updating of EP procedures, installation of cameras, implementation of a wall at the swale, increase in monitoring/inspections, etc. Duke indicated that it intends to send its supplemental letter which will provide a comprehensive list of the CMs and implementation dates.
Subsequently, by letter dated June 3, Duke provided a comprehensive list of interim compensatory measures to be implemented at the Oconee site and the Jocassee Dam, including additional compensatory measures, and also provided a schedule for the implementation of the compensatory measures. Duke also indicated that their new compensatory measures included a flood protection wall that was built on the north end of the Owner Controlled Area protecting the area designated as the 'swale" in correspondence. And, a flood levee is being built on the intake dike and has been reviewed by FERC with no issues raised. The wall is sectional and has been used out in the mid-west along the major rivers for flood protection in lieu of sandbags. The wall will be built in 2 foot high sections to a final height of 10 feet. The wall will be 580 feet long and 6.5 feet wide and then filled with 22,000 tons of sand. The 1 st 2 foot high section is in place and work is in progress to complete the wall. This will divert water away from the west yard and the SSF.
This week (June 7), Region II, with NRR support, will be conducting an inspection of the ICMs.
DORL has drafted an Order for issuance to Duke for (1) confirmation of the implementation of the ICMs, (2) final documentation justifying inundation of Oconee site following a random failure of the Jocassee Dam and (3) a schedule for all modifications necessary to mitigate the inundation by Nov. 30, 2010. The Order is scheduled for issuance in the very near future.
DE with DRA's support has entered the Oconee external flooding issue into the RES' Generic Issues Program.
Quarterly NRC/Duke senior management meetings will be held to continue effective communications on this issue as well as the other issues that exist at Oconee (tornado/HELB, NFPA 805, digital RPS, etc.).
PIs. contact George Wilson, John Stang, or myself if you have any questions.
- Thanks, M eena IOTNY,ý A 1 ý0 "N-,Ofi6Y EC\\ RITY,- KEi~RF 2