ML20083K237
| ML20083K237 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 01/09/1979 |
| From: | Clayton F ALABAMA POWER CO. |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7901170176 | |
| Download: ML20083K237 (2) | |
Text
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Alabama Pcwer Company f"N
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Pcst O' fee Bos 2641 9mmgmarn. Aacama 33291 Teseancee 205 323 5341 m
F. L CLAYTON, JR.
[ghgg3 gry Senior Vice F*e$6 Cent the soumem eectre sys:em January 9, 1979 Docket No. 50-318 s
Director of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Attn:
Mr. Albert Schwencer Gentlemen:
J. M. FARLEY NUCLEAR PLANT-UNIT 1 l
CONTAINMENT PURGING DURING NORMAL PLANT OPERATION This letter is in response to Mr. A. Schwencer's letter to Alabama Power Company dated November 28, 1978 concerning containment purging during normal plant operation for the Farley Nuclear Plant Unit 1.
The containment purge system for the Farley Nuclear Plant has the capability to purge the containment through 48 inch valves or 16 inch valves.
The 48 inch purge valves are used for limited' purging and the 18 inch mini-purge valves are used to continuously purge the containment'during plant operation. These. mini-purge valves are designed to close against a pressure I
of 53.5 psig, but have been tested to close against a' pressure of 65 psig.
A diagram illustrating this system is enclosed.
l Alabama Power Company is conducting an evaluation which will justify unlimited purging using the mini-purge system during power operation. Justi-fication will be provided in response to NRC' Branch Technical Position CSB 6-4 by February.2,.1979.
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Alabama Power Company plans to conduct an evaluation to justify limited purge with 48 inch purge valves at a later date. A schedule for completion of this evaluation will be forwarded when finalized.
In addition, Alabama Power Compa-has, reviewed the Millstone inciderts described in the above letter in light of the Farley Nuclear Plant design.
It was identified that the Millstone control board is designed with some switches which are spring loaded to a center position (auto position).
If one wished to maintain contact, the switch cont'rol handle could be pulled out and turned to the "on" position, and the switch would lock out all auto-matic signals and maintain contact. _ However, the Farley Nuclear Plant does REGU _AT0iY LOOET FE Zy
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Mr. Albert Schwencer Page Two January 9, 1979 If an operator needs to not have this type of switch on its control board.
he time, override automatic signals, he has to hold the control switc
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is different from the control circuitry design of the Farley ;iuclear P ant that of the Millstote Plant.
l We have performed a review of the design of the saf ety actuation signa It eas circuits for the Containment Purge System (including mini-purge).
l determined that' overriding the safety actuation signal for those partic valves is not possible.
l d by circuits which incorporate a manual override feature will be comp ete February 2, 1979.
APCo plans to continue purging with the mini-purge system during opera-1979. The 48 inch purge tion as discussed with the NRC Staff on January 5, i
in hot shut-valves will be restricted to an absolute minimum while operat ngto exceed 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per down, hot standby, startup and power operation, not year pending completion of NRC review.
Should you have any question concerning the above, please advise.
Yours truly, Ph D
A
-h h. Clay n, Jr[
FLCJr/TNE:bhj Mr. R. A. Thomas cc:
Mr, G. F. Trowbridge 4
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