ML20010G676

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Final Deficiency Rept Re Available NPSH for Recirculation Spray Pumps,Originally Reported on 770812.Recirculation Spray Pump Arrangement Has Been Modified to Set Pumps Lower in Elevation.Assumptions Used Are Conservative
ML20010G676
Person / Time
Site: North Anna Dominion icon.png
Issue date: 09/09/1981
From: Spencer W
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 378, NUDOCS 8109220399
Download: ML20010G676 (1)


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Mr. James P. O'Reilly, Director Serial No. 378 '

Office of Inspection & Enforcement PSE&C/MFf 1:brc ,a U.S. Nuclear Regulatory Connission ~

Region II Docket No. 50-404 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

On August 12, 1977, NRC Region II was notified under the provisions of 10CFR 50.55(e) concerning the available net positive suction head (NPSH) for the recirculation spray pumps installed on ferth Anna Power Station Units 3 and 4. This notification was followed by a five-day report on August 18, 1977, in accordance with reporting requirements of 10CFR21.

The report stated that an analysis had indicated that under certain postulated past LOCA cor.ditions the available NPSH for the recirculation spray pumps could be less than required.

Subsequently, the recirculation spray pump arrangement has been modified to set the pumps lower in elevation which increases the NPSH available at the pump suction. The modified pump arrangement provides a minimum margin of 25 percent of NPSH available over and above that required for satisfactory pump operation for all postulated post LOCA conditions.

The assumptions used in determining the modified pump arrangement are conservative. We are confident that the modified pump arrangement ensures satisf actory perfonnance of these pumps during all postulated post LOCA conditions.

We anticipate no further correspondence on this subject. Therefore, this letter is consiaered to be c final report and completes all report ug requirements under provisions of 10CFR 50.55(e) and/or 10CFR 50.21.

Very trul yours, W. C. Spencer T&7 5 Vice President - Power Station Engineering ar.d Construction Services

,h cc: Mr. Robert L. Tedesco Division of Licensing F109220399 s10909 PDR ADOCK 05000404 S pyg

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