ML031970466
| ML031970466 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 07/07/2003 |
| From: | Hartz L Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 03-150B, SPSLIC/CGL R1 | |
| Download: ML031970466 (5) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 July 7, 2003 U.S. Nuclear Regulatory Commission Serial No.
03-150B Attention: Document Control Desk SPSLIC/CGL R1 Washington, D.C. 20555 Docket Nos.
50-280 50-281 License Nos.
DPR-32 DPR-37 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 PROPOSED TECHNICAL SPECIFICATIONS CHANGE BURIED FUEL OIL STORAGE TANK INSPECTION AND RELATED REPAIR REQUEST FOR ADDITIONAL INFORMATION In a letter dated September 5, 2002 (Serial No.02-561), Virginia Electric and Power Company (Dominion) requested changes to the Surry Power Station Units 1 and 2 Technical Specifications (TSs). These changes include the addition of a 7-day allowed outage time for a buried fuel oil storage tank to permit the inspection and, if necessary, related repair of the tank during plant operation.
Subsequently, in letters dated April 16, 2003 and June 9, 2003 (Serial Nos.03-150 and 03-150A, respectively)
Dominion provided responses to NRC requests for additional information (RAI) regarding the proposed TS change. During staff review of the RAI responses, the NRC identified additional information necessary to complete their review. A conference call was held on June 24, 2003. At the conclusion of the conference call, Dominion agreed to provide a written response to the NRC's additional RAI. This response is provided in the attachment.
We have evaluated the proposed TS change previously submitted with respect to the supplemental information provided herein and have determined that the supplemental information does not require revision of the No Significant Hazards Consideration or Environmental Assessment provided in our September 5, 2002 submittal.
If you have any further questions or require additional information, please contact Mr. Gary D. Miller at (804) 273-2771.
Very truly yours, Leslie N. Hartz Vice President - Nuclear Engineering Attachment
Commitments made in this letter: None cc:
U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center Suite 23T85 61 Forsyth Street, SW Atlanta, Georgia 30303 Mr. C. Gratton NRC Senior Project Manager U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 8G9 Rockville, MD 20852 Mr. R. A. Musser NRC Senior Resident Inspector Surry Power Station Commissioner Bureau of Radiological Health 1500 East Main Street Suite 240 Richmond, VA 23218
SN: 03-150B Docket Nos.: 50-280/281
Subject:
RAI - Proposed TS Change Buried Fuel Oil Storage Tank Inspection & Related Repair COMMONWEALTH OF VIRGINIA
)
)
COUNTY OF HENRICO
)
The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Leslie N. Hartz, who is Vice President - Nuclear Engineering, of Virginia Electric and Power Company. She has affirmed before me that she is duly authorized to execute and file the foregoing document in behalf of that Company, and that the statements in the document are true to the best of her knowledge and belief.
Acknowledged before me this 7th day of July, 2003.
My Commission Expires: March 31, 2004.
(SEALNotary Public (SE-Al,
ATTACHMENT Response to NRC Request for Additional Information -
Proposed Technical Specifications Change Request Buried Fuel Oil Storage Tank Inspection/Repalr Surry Power Station Units 1 and 2 Virginia Electric and Power Company (Dominion)
QUESTION:
What are the Conditional Core Damage Frequency (CCDF) and Conditional Large Early Release Frequency (CLERF), given a Loss of Offsite Power (LOOP) event, with and without a buried storage tank available? What is the associated risk increase?
RESPONSE
In order to respond to this question, two cases were run. Both cases assumed a LOOP, one case assumed both buried fuel oil tanks (2A and 2B) are in service, and the other case assumed the 2A tank is in service and the 2B tank is out of service. The results of these runs are as follows:
Conditional Conditional Case Core Damage Large Early Release Frequency Frequency
- 1) LOOP frequency = 1.0 6.032E-5/yr 1.077E-6/yr
- 2) LOOP frequency = 1.0 with 7.648E-5/yr 1.1 83E-6/yr 1-EE-TK-2B unavailable Increase 1.616E-5/yr 1.06E-7/yr It should be noted that there is no provision in the Tier 2 process of Regulatory Guide 1.177 to consider such large initiator uncertainties (factor of 30 greater than the mean value assumed in the PRA). Therefore, the usefulness of these results is unclear.
The calculations are also conservative for the following reasons:
The buried tank unavailability is 4E-3 (seven days per buried tank every ten years).
Approximately 98% of LOOP events are recovered before one buried tank is depleted; thus the applicable LOOP frequency is -2E-2/yr (see letter Serial No. 03-150A, dated June 9, 2003).
The Surry model takes no credit for the above ground storage tank, the Gravel Neck facility, or the offsite replacement fuel oil supply. The concurrent unavailability of these three sources may be conservatively estimated at well below 1.OE-3.
Therefore, the CCDF increase considering these conservatisms is actually closer to
-1.OE-10/yr and the CLERF increase is even less, assuming a LOOP occurs while one buried tank is out of service.
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