ML20004B965
| 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.
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Alabama Power the southem electnc system May 26, 1981 O
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Docket No. 50-348 No. 50-364 nL 6
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Director, Nuclear Reactor Regulation C/
U. S. Nuclear Regulatory Commission
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N Washington, D. C.
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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 Farley, since the TMI-2 accident.
In addition, comparing the results of i
l this study to the WASH-1400 median frequency of a small-break LOCA of 10-3, 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 9
l 4
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, m.s u s u k,'
4 L w /1.s 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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