ML101610083

External Flood Commitments

ML101610083
Person / Time
Site:	Oconee
Issue date:	06/03/2010
From:	Baxter D Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
FOIA/PA-2012-0128
Download: ML101610083 (5)

Text

SDuke "Energy. DAVE BAXTER Vice President Oconee Nuclear Station Duke Energy ONO VP / 7800 Rochester Highway Seneca, SC 29672 864-873-4460 864-873-4208 fax dave. baxter@duke-energy.com June 3, 2010 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C., 20555-001

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station, Units 1, 2, and 3 Renewed Facility Operating License, DPR-38, DPR-47, and DPR-55 Docket Numbers 50-269, 50-270, and 50-287 Oconee External Flood Commitments

References:

1. Duke Energy Letter From Dave Baxter to NRC Document Control Desk, "Oconee External Flood Analyses and Associated Corrective Action Plan," dated November 30, 2009

2. Duke Energy Letter From Dave Baxter to NRC Document Control Desk, "Oconee External Flood Interim Actions" dated January 15, 2010

3. Duke Energy Letter From Dave Baxter to NRC Document Control Desk, "Oconee External Flood Interim Action Plan; Revision of Commitment from January 15, 2010, Letter," dated May 27, 2010

4. Duke Energy Letter From Dave Baxter to NRC Document Control Desk, "Response to 10 CFR 50.54(f) Request [NRC Letter dated August 15, 2008]," dated September 26, 2008 By letter dated November 30, 2009 (Reference 1), Duke Energy Carolinas, LLC (Duke Energy) provided the NRC with additional information to address the potential consequences of external flooding, including a postulated failure of the Jocassee Dam. As a follow-up to a December 2, 2009, meeting, Duke Energy provided additional information concerning external flood interim actions in a letter dated January 15, 2010 (Reference 2), modified in part by letter dated May 27, 2010 (Reference 3).

Attachment 2 of Reference 2 and Attachment 4 of Reference 4 provided a list of interim commitments that included actions to enhance prevention/detection activities and mitigation strategies. During a meeting with the NRC on May 26, 2010, Duke Energy agreed to provide an update to the interim commitments previously submitted to the NRC. Duke Energy hereby submits an update which supersedes any and all previous commitments previously submitted to the NRC related to potential consequences of external flooding, including a postulated failure of the Jocassee Dam:

Attachment 1,."Status of External Flood Commitments," provides commitments that have been implemented or will be implemented to provide additional assurance of adequate protection against external flooding at ONS.

This letter contains security sensitive information. J/1*4-1*

Withhold from Public Disclosure under 10 CFR 2.390 (d)(1) www. duke-energy, com

U.S. Nuclear Regulatory Commission June 3, 2010 Page 2 In an ongoing effort to improve the quality of interim actions to address external flood concerns, Duke Energy has enhanced in-place guidance that addresses postulated flood events which could render the Standby Shutdown Facility (SSF) inoperable and has plans for additional enhancements. Furthermore, we have implemented all Jocassee-related commitments that were due to be implemented by May 2010.

Duke Energy has also created procedures to address mitigation of postulated flood events which could render the SSF inoperable. The objective of those procedures is to prevent fuel damage and the release of radioactivity that could affect public health and safety. Should Duke Energy identify the need to take corrective action associated with any commitment-related equipment or procedure issue, then those actions will be implemented in a time frame commensurate with the safety significance of the issue.

Since this letter contains security sensitive information, Duke Energy hereby requests the NRC withhold the letter from public disclosure pursuant to 10 CFR 2.390 (d)(1), "Public inspections, exemptions, requests for withholding."

If you have any questions on this matter, please contact Bob Meixell, Oconee Regulatory Compliance, at 864-873-3279 or Jeff Thomas, Fleet Regulatory Compliance Manager, at 704-382-3438.

I declare under penalty of perjury that the foregoing is true and correct. Executed on; June 3, 2010.

Sincerely, Da e Baxter, Vice President Oconee Nuclear Station Attachments

1. Status of External Flood Commitments This letter contains security sensitive information.

Withhold from Public Disclosure under 10 CFR 2.390 (d)(1)

U.S. Nuclear Regulatory Commission June 3, 2010 Page 3 bc:

Mr. Luis Reyes U.S. Nuclear Regulatory Commission, Region II Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. J.F. Stang, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 0-8 G9A Washington, DC 20555 Mr. Andrew Sabisch NRC Senior Resident Inspector Oconee Nuclear Station Susan E, Jenkins, Manager, Infectious and Radioactive Waste Management Bureau of Land and Waste Management Department of Health & Environmental Control 2600 Bull Street, Columbia, SC 29201 This letter contains security sensitive information.

Withhold from Public Disclosure under 10 CFR 2.390 (d)(1)

Attachment 1 Status of External Flood Commitments Number Commitment Status

1. Perform flooding studies using the Hydrologic Engineering Center - River Complete Analysis System (HEC-RAS) model for comparison with previous DAMBRK models to more accurately represent anticipated flood heights in the west yard following a postulated failure of the Jocassee Dam.

2. Maintain plans, procedures (Jocassee and Oconee) and guidance documents Implemented (Oconee) to address mitigation of postulated flood events which could render the Standby Shutdown Facility inoperable and are consistent with current perspectives gained following the HEC-RAS sensitivity studies and the subsequent 2D inundation studies. To the extent practical, the mitigation strategy is similar to existing extensive plant damage scenario (B.5. b) equipment, methods and criteria.

3. Duke Energy Hydro Generation will create a guidance document to Implemented consolidate river management and storm management processes. (Includes the Jocassee Development and the Keowee Development.)

4. Maintain a dam safety inspection program that includes: (1) weekly dam safety Implemented inspections of the Jocassee Dam by Duke Energy personnel, (2) dam safety inspections following any 2-inch or greater rainfall or felt seismic event, (3) annual dam safety inspections by Duke Energy, (4) annual dam safety inspections by FERC representatives, (5) five year safety inspections by FERC approved consultants, and (6) five year underwater inspections

5. Maintain a monitoring program that includes: (1) continuous remote monitoring Implemented from the Hydro Central Operating Center in Charlotte, NC, (2) monthly monitoring of observation wells, (3) weekly monitoring of seepage monitoring points, and (4) annual surveys of displacement monuments

6. Assign an Oconee engineer as Jocassee Dam contact to heighten awareness Implemented of Jocassee status.

7. Install ammeters and voltmeters on Keowee spillway gates for equipment Complete condition monitoring.

8. Ensure forebay and tailrace level alarms are provided for Jocassee to support Complete timely detection of a developing dam failure

9. Add a storage building adjacent to the Jocassee spillway to house the backup Complete spillway gate operating equipment (e.g., compressor and air wrench)

10. Obtain and stage a portable generator and electric drive motor near the Complete Jocassee spillway gates to serve as a second set of backup spillway gate operating equipment.

1 This Attachment contains security sensitive information.

Withhold from Public Disclosure under 10 CFR 2.390 (d)(1)

Attachment 1 Status of External Flood Commitments Number Commitment Status

11. Conduct Jocassee Dam failure Table Top Exercise with Oconee participation To be to exercise and improve response procedures completed June 2010

12. Instrument and alarm selected seepage monitoring locations for timely To be detection of degrading conditions completed August 2010

13. Provide additional video monitoring of Jocassee Dam (e.g., dam toe, To be abutments, and groin areas) for timely assessment of degrading conditions completed August 2010

14. Obtain and stage a second set of equipment (including a B.5.b-type pump) for To be implementation of the external flood mitigation guidance. completed November 2010

15. Conduct Jocassee Dam/Oconee Emergency Response Organization Drill to To be exercise and improve response procedures completed December 2010 NOTES:

1. The word "complete" is used in the status column if the commitment regards a specific one-time equipment-related or analysis-related action that has been completed.

2. The word "implemented" is used in the status column if the commitment describes an on-going action that has been implemented.

2 This Attachment contains security sensitive information.

Withhold from Public Disclosure under 10 CFR 2.390 (d)(1)