ML20004B965

Advises That Automatic Power Operated Relief Valve Isolation Sys Not Needed.Assessment Performed Per NUREG-0737,Item II.K.2 Submitted as WCAP-9804,by Westinghouse Owners Group 810313 Ltr

ML20004B965
Person / Time
Site:	Farley
Issue date:	05/26/1981
From:	Clayton F ALABAMA POWER CO., ARKANSAS POWER & LIGHT CO.
To:	Varga S, Youngblood B NRC
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.K.1, TASK-2.K.2, TASK-TM NUDOCS 8106010362
Download: ML20004B965 (2)

Text

Malling Address Al:tnma PowLr CompIny o 600 No.-th 18th street Post Office Box 2641 8

Birmingham. Alabama 35291 A Telepnone 205 783-6081 F. L. Clayton. Jr.

gg,0c;%y"' Alabama Power the southem electnc system May 26, 1981 F  % O Docket No. 50-348 , .

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No. 50-364 nL 6 .J g mat 2A1981= i D u.a. 4 i

• 3 Director, Nuclear Reactor Regulation N C/

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U. S. Nuclear Regulatory Commission Washington, D. C. 20555 q y Attention: Mr. S. A. Varga Mr. B. J. Youngblood Gentlemen:

JOSEPH M. FARLEY NUCLEAR PLANT - UNITS 1 AND 2 NUREG-0737, ITEM II.K.1 AND NPF-8 LICENSE CONDITION 2.C(P.1)(i)(1)

In accordance with the requirements of NUREG-0737, Item II.K.1 and the Farley Nuclear Plant-Unit 2 Operating License NPF-8 [Section 2.C.(21)

(i)(1)], Alabama Power Company, as a member of the Westinghouse Owner's Group, has assessed the possibility of installing an automatic Power ,

Operated Relief Valve (PORV) isolation system (NUREG-0737, Item II.K.1).

This system would automatically isolate the PORV by closing the PORV bicck valve on receipt of a low pressurizer pressure signal following a PORV opening. The assessment was made as part of the report documenting the actions taken since the TMI-2 accident to decrease the probability of a small-break loss-of-coolant-accident (LOCA) caused by a struck open PORV. This report was prepared in response to NUREG-0737, Item II.K.2 and submitted to the Nuclear Regulatory Commission as WCAP-9804 by Westinghouse Owner's Grouo letter 0G-52 on March 13, 1981.

The studies in WCAP-9804 show that the probability of a small-break to 2.1X10-6 LOCA caused by a stuck open gCR\' has beeg reduced by 78%, IX10-0 per reactor year and 0.5X10- to 0.9X10- per reactor year for high head and low head plants, respectively, due to the hardware, setpoint, admin-istrative and training changes made by Westinghouse plants, including i Farley, since the TMI-2 accident. In addition, comparing the results of this study to the WASH-1400 median frequency of a small-break LOCA of 10-3, l

both the pre- and post-TMI calculations are not a significant contributor l

to the probability of a small-break LOCA. Thus, due to the large reduction in the probability of a PORV-LOCA already achieved since the TMI-2 accident, 810000i N ,

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4 Director, Nuclear Reactor Regulation May 26, 1981 U. S. Nuclear Regulatory Commission Page 2 the concept of an automatic PORV block valve closure system cannot be warranted on the basis of providing additional protection against a PORY LOCA. Therefore, it is Alabama Power Company's position that an automatic PORY block valve closure system is not needed and a description of a sistem need not be submitted.

If you have any questions, please advise.

Very truly yours, L w .s 4 u s

/1.s u k ,'

m F.L.Clayton,Jrl. -

FLCJr/RWS:de cc: Mr. R. A. Thomas Mr. G. F. Trowbridge Mr. J. P. O'Reilly Mr. E. A. Reeves

> Mr. J. O. Thoma Mr.11. H. Bradford

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