ML040130548
| ML040130548 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/18/2003 |
| From: | Rosalyn Jones Duke Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML040130548 (3) | |
Text
Duke R.
A. JONES
- rPower, Vice President A Duke Energy Company Duke Power 29672 / Oconee Nuclear Site 7800 Rochester Highway Seneca, SC 29672 864 885 3158 864 885 3564 tax December 18, 2003 U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Document Control Desk
Subject:
Oconee Nuclear Station Docket Numbers 50-269, 270, and 287 December 16, 2003, NRC Meeting on Temporary Allowed Outage Time Extensions for Inoperable Keowee Hydro Units Duke Energy Corporation (Duke) met with NRC personnel on December 16, 2003, to discuss our request to temporarily extend the allowed outage times (AOTs) for inoperable Keowee Hydro Units (KHUs).
Duke submitted a license amendment request to temporarily extend the Technical Specification (TS) AOTs for one or two inoperable Keowee Hydro Units (KHUs) on August 22, 2002 (and supplemented on September 12, 2003) to support planned Keowee maintenance activities.
During several recent conference calls, the NRC had requested Duke to evaluate the feasibility of installing temporary diesel generators (DGs) as an additional risk reduction measure to support the proposed license amendment.
As part of that feasibility study, Duke also evaluated the risk benefits associated with installing DGs.
Duke presented the results of that feasibility study during the meeting.
Based on dialogue during the meeting, Duke concludes that NRC is in agreement that adding temporary DGs provides minimal risk benefits and as a result does not intend to further pursue installing DGs.
During the meeting, Duke provided revised risk numbers for the planned Keowee maintenance activity based on the recently approved new seal LOCA model and additional risk reduction measures.
Duke believes the revised cumulative core damage probability (CCDP)of 4.4E-7 coupled with the defense-in-depth measures conveyed during the meeting provide adequate www. duke-energy. corn
U. S. Nuclear Regulatory Commission December 18, 2003 Page 2 of 4 justification to support the proposed temporary license amendment using the guidelines of Regulatory Guide 1.174.
These defense-in-depth measures address grid-related events, weather-related events, and switchyard-centered events that could result in a loss of offsite power.
These measures include a 100 kV line separated from the switchyard, a Lee Combustion Turbine (LCT) already running and energizing the standby buses via that line, two additional LCTs either of which can also provide the necessary emergency power, one Jocassee hydro unit available and capable of providing necessary emergency power via a dedicated line separated from the grid, three additional Jocassee hydro units any of which can also provide the necessary emergency power, power lines that approach Oconee from different directions reducing the likelihood of losing all offsite power at the same time, and the Standby Shutdown Facility (SSF) remaining available after any of these events.
Duke will provide additional details regarding these defense-in-depth measures in a supplement to the LAR.
During this meeting Duke committed to provide additional risk reduction measures and to submit revised cumulative core damage probability numbers.
Duke will provide this information in a supplement to the License Amendment Request (LAR).
Duke appreciated the opportunity to meet with the Staff so that long-term improvements to the Keowee Hydro Units can proceed on the current schedule.
If there are any questions regarding this submittal, please contact Boyd Shingleton at (864) 885-4716.
Very t ly yours, R.
- ones, Vice President Oconee Nuclear Site
U. S. Nuclear Regulatory Commission December 18, 2003 Page 3 of 4 cc:
Mr. L. N. Olshan, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 0-14 H25 Washington, D. C.
20555 Mr. L. A. Reyes, Regional Administrator U. S. Nuclear Regulatory Commission -
Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303 Mr. M. C. Shannon Senior Resident Inspector Oconee Nuclear Station Mr. Henry Porter, Director Division of Radioactive Waste Management Bureau of Land and Waste Management Department of Health & Environmental Control 2600 Bull Street Columbia, SC 29201