ML13066A628
| ML13066A628 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/22/2010 |
| From: | Veronica Rodriguez Division of Inspection and Regional Support |
| To: | Jeffrey Mitman NRC/NRR/DRA/APOB |
| References | |
| FOIA/PA-2012-0325 | |
| Download: ML13066A628 (5) | |
Text
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1 Mitman, Jeffrey From:
Rodriguez, Veronica Sent:
Monday, November 22,2010 4:27 PM To:
Mitman, Jeffrey Cc:
Wong, See-Meng
Subject:
RE: draft letter to FERC Jeff... the letter looks ok to me.
The term "absolute assurance" is odd to me though. Are you ok w/this term?
From: Mitman, Jeffrey Sent: Monday, November'22,2010 11:14 AM To: Rodriguez, Veronica Cc: Wong, See-Meng
Subject:
RE: draft letter to FERC My comments to the attached draft letter are incorporated via Word revision marks. Is it OK to send this back to DE?
Jeff Mitman
- From :_ W ilson, Geoirge-ýýO -..
Sent: Wednesday, November 17, 2010 7:09 AM To: Mitman, Jeffrey; Coleman, Neil; Wescott, Rex; Stang, John; Persinko, Andrew; Scott, Catherine; Khanna, Meena; Sexton, Kimberly; Simon, Marcia Cc: Hiland, Patrick; Cunningham, Mark
Subject:
draft letter to FERC Please look at the draft letter and provide comments George Wilson USNRC Acting Deputy Director, Division of Engineering Mail Stop 012H2 301-415-1711 1
Mitman, Jeffrey From:
Mitman, Jeffrey
/
Sent:
Monday, November 22, 2010 11:43 AM To:
Wong, See-Meng; Rodriguez, Veronica
Subject:
RE: draft letter to FERC See Meng, we can but it is not necessary. The sender and receiver of the email will clearly understand the meaning and its significance. Adding an appropriate definition will take significant verbiage that is unwarranted.
Jeff From: Wong, See-Meg~.-.
Sent: Monday, November 22, 2010 11:35 AM To: Mitman, Jeffrey; Rodriguez, Veronica
Subject:
RE: draft letter to FERC
- Jeff, Can we provide a short phrase (in parentheses) to say what a "sunny day" failure is, or there is no plain language definition available?
See Meng.
From: Mitman, Jeffrey Sent: Monday, November 22, 2010 11:14 AM To: Rodriguez, Veronica Cc: Wong, See-Meng
Subject:
RE: draft letter to FERC My comments to the attached draft letter are incorporated via Word revision marks. Is it OK to send this back to DE?
Jeff Mitman From: Wilson, George Sent: Wednesday, November 17, 2010 7:09 AM To: Mitman, Jeffrey; Coleman, Neil; Wescott, Rex; Stang, John; Persinko, Andrew; Scott, Catherine; Khanna, Meena; Sexton, Kimberly; Simon, Marcia Cc: Hiland, Patrick; Cunningham, Mark
Subject:
draft letter to FERC Please look at the draft letter and provide comments George Wilson USNRC Acting Deputy Director, Division of Engineering Mail Stop 012H2 301-415-1711 1
OF FIICTY RUSEEDNL'-NYSAE Mr. Daniel J. Mahoney, Director Division of Dam Safety and Inspections Federal Energy Regulatory Commission Office of Energy Projects
SUBJECT:
Oconee Intake Dike - External Flood Diversion Barrier
Dear Mr. Mahoney:
By letter dated, September 13, 2010, the Federal Energy Regulatory Commission (FERC) requested that the U.S. Nuclear Regulatory Commission (NRC), confirm that the temporary structure on the Oconee Intake Dike, is a beneficial or prudent feature of the Oconee Nuclear Station (ONS) Safe Shutdown Facility (SSF) protection project that adds to the interim flood protection of the SSF.
Duke provided the NRC staff with 2D modeling runs of the flooding inundation caused by a "sunny day" failure of the Jocassee Dam-st"y utilizing the existing temporary intake dike wall.
Those model runs showed that there would be a reduction in the water level from approximately 19 ft. to 5.5 ft. at the SSF on the ONS site. It is noted that the SSF is currently protected by a 7.5 ft. wall; therefore, the current wall provides protection for the SSF, in the above scenario.
The SSF provides equipment for additional accident mitigation at the site. The present intake dike wall structure is not designed to be water tight and does not meet FERC's design criteria.
There is no positive upstream cutoff water barrier and uplift was not analyzed in the stability analysis. Based on this information, there is not an absolute assurance that the intake dike wall I structure will perform in a manner that the analysis predicts; however there is a gee4-likelihood that the intake dike wall act as a flood diversion barrier as depicted in the 2D modeling I r-u4analysis. The NRC staff agrees that if the intake dike wall performs the function of a flood diversion barrier then it is beneficial for an interim flood protection measure at the ONS.
If you have any questions, please contact me at (301)415-1711.
Sincerely, George Wilson, Dam Safety Officer Division of Engineering Office of Nuclear Reactor Regulation US NRC cc: Charles Wagner, FERC OFFI L UýNL/EC LMFLTDý
November 30, 2010 Mr. Daniel J. Mahoney, Director Division of Dam Safety and Inspections Federal Energy Regulatory Commission Room 6N-01 888 First Street, NE Washington, DC 20426
SUBJECT:
OCONEE INTAKE DIKE - EXTERNAL FLOOD DIVERSION BARRIER
Dear Mr. Mahoney:
In your letter to Duke Energy (Duke) dated September 13, 2010, you indicated that, in order to authorize Duke to complete construction of the temporary structure (wall) on the Oconee Intake Dike, you would need the U.S. Nuclear Regulatory Commission (NRC) to confirm that the temporary structure is a beneficial or prudent feature of the Oconee Nuclear Station (ONS) Safe Shutdown Facility (SSF) protection project that adds to the interim flood protection of the SSF.
In subsequent telephone conversations between the NRC and you and your staff, the Federal Energy Regulatory Commission (FERC) requested that the NRC provide this confirmation. This letter addresses that request.
Duke provided the NRC staff with 2D modeling runs of the flooding inundation study, utilizing the existing temporary intake dike wall. Those model runs showed that there would be a reduction in the water level from approximately 19 ft. to 5.5 ft. at the SSF on the ONS site with the intake dike wall in place. It is noted that the SSF is currently protected by a 7.5 ft. wall; therefore, the current wall protecting the SSF would be adequate in the above scenario. The SSF provides equipment for additional accident mitigation at the site. The NRC staff agrees that if the intake dike wall performs the function of a flood diversion barrier, then it is beneficial as an interim flood protection measure at the ONS.
The NRC staff greatly appreciates all the help and support that has been provided by you and your staff on this issue. We also look forward to hearing from you and your staff on your evaluation of the proposed permanent mitigating structures proposed by Duke on the site.
If you have any questions, please contact me at (301) 415-1711.
Sincerely,
/RA/ M.Khanna for George A. Wilson, Dam Safety Officer Division of Engineering Office of Nuclear Reactor Regulation
November 30, 2010 Mr. Daniel J. Mahoney, Director Division of Dam Safety and Inspections Federal Energy Regulatory Commission Room 6N-01 888 First Street, NE Washington, DC 20426
SUBJECT:
OCONEE INTAKE DIKE - EXTERNAL FLOOD DIVERSION BARRIER
Dear Mr. Mahoney:
In your letter to Duke Energy (Duke) dated September 13, 2010, you indicated that, in order to authorize Duke to complete construction of the temporary structure (wall) on the Oconee Intake Dike, you would need the U.S. Nuclear Regulatory Commission (NRC) to confirm that the temporary structure is a beneficial or prudent feature of the Oconee Nuclear Station (ONS) Safe Shutdown Facility (SSF) protection project that adds to the interim flood protection of the SSF.
In subsequent telephone conversations between the NRC and you and your staff, the Federal Energy Regulatory Commission (FERC) requested that the NRC provide this confirmation. This letter addresses that request.
Duke provided the NRC staff with 2D modeling runs of the flooding inundation study, utilizing the existing temporary intake dike wall. Those model runs showed that there would be a reduction in the water level from approximately 19 ft. to 5.5 ft. at the SSF on the ONS site with the intake dike wall in place. It is noted that the SSF is currently protected by a 7.5 ft. wall; therefore, the current wall protecting the SSF would be adequate in the above scenario. The SSF provides equipment for additional accident mitigation at the site. The NRC staff agrees that if the intake dike wall performs the function of a flood diversion barrier, then it is beneficial as an interim flood protection measure at the ONS.
The NRC staff greatly appreciates all the help and support that has been provided by you and your staff on this issue. We also look forward to hearing from you and your staff on your evaluation of the proposed permanent mitigating structures proposed by Duke on the site.
If you have any questions, please contact me at (301) 415-1711.
Sincerely, IRA/ M.Khanna for George A. Wilson, Dam Safety Officer Division of Engineering Office of Nuclear Reactor Regulation DISTRIBUTION: CWagner RidsNrrDorl RidsNrrDRA RidsNrrOd ADAMS ACCESSION NO.: ML103280287 OFFICE NRR/DE/EMCB NRR/DE NRR/DE NAME MKhanna PHiland GWilson DATE 11/30/10 11/30/10 11/30/10 SFFICIAL RECORD COPY
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