ML18139B614
| ML18139B614 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 11/09/1981 |
| From: | Leasburg R VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Varga S Office of Nuclear Reactor Regulation |
| References | |
| 594, NUDOCS 8111130480 | |
| Download: ML18139B614 (2) | |
Text
e VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND,. VIRGINIA 23261 R. H. LEASBURG VICE PRESIDENT NUCLEAB 0l'ERATIONS Mr. Harold R. Denton, Director November 9, 1981 Office of Nuclear Reactor Regulations Attn:
Mr. Steven A. Varga, Chief Operating Reactors Branch No. 1 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Serial No. 594 NO/LEN/jmj Docket Nos. 50-280 50-281 License Nos. DPR-32 DRP-37 AUXILIARY FEEDWATER SYSTEM RELIABILITY SURRY POWER STATION On September 25, 1979, the NRG sent us a letter requesting certain information regarding the design basis for the Auxiliary Feedwater (AFW) system for Surry Power Station Units 1 and 2.
Vepco responded with a letter dated December 26, 1980.
As stated in that letter, the design basis of the AFW system includes consideration of the Loss of Normal Feedwater (LONF) Transient.
However, the Feedline Break (FLB) event was excluded since this event is not part of the Surry plant design basis.
In your letter of October 1, 1981, you requested that Vepco assess the capability of the AFW system under postulated feedline break conditions.
Vepco has per-formed this review, and has determined that at least 350 gpm of AFW flow can be supplied to two steam generators during a feedline break, asstllrting no operator action and failure of the highest capacity AFW pump to function.
Furthermore, Vepco has reviewed the analysis of the feedline break event presented in Chapter 15 of the North Anna FSAR.
The North Anna analysis assumes a higher power rating (2910 MWT Engineering Safeguards rating vs 2554 l~~T for Surry) and the AFW capability available at Surry is greater than the 350 gpm of AFW flow assumed in* the North Anna analysis.
Since the North Anna analysis has assumed more limiting values for the key analysis assumptions, we have-concluded that the results of the FLB analysis in the North Anna FSAR con-servatively bound the results for Surry.
In addition, since the.AFW flow required for meeting the condition IV criteria for the FLB event is less than the flow required for the condition II Surry LONF event (350 vs 500 gpm), our letter of December 26, 1980, which identified-the LONF as the design basis of the Surry AFW system, remains valid.
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e VIRGINIA ELECTRIC AND POWER COMPANY TO Should you have any further questions, please contact this office.
cc:
Mr. James P. O'Reilly, Director Office of Inspection and Enforcement Region II Very truly yours, GJ\\_~
~ R.H. Leasburg 2