ML20138S049

Safety Evaluation Approving Util 850109,0408 & 0830 Submittals Re Alternate Shutdown Capability in Event of Fire in Fire Area 34B-West

ML20138S049
Person / Time
Site:	Fort Calhoun
Issue date:	11/04/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20138S045	List: ML20138S044 ML20138S049
References
NUDOCS 8511190430
Download: ML20138S049 (1)

Text

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UNITED STATES

[ g NUCLEAR REGULATORY COMMISSION 5 g WASHINGTON, D. C. 20555

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR PEGULATION OMAHA PUBLIC POWER DI5TRICT .'

FORT CALHOUN STATION, UNIT NO. 1 DOCKEl NO. 50-Z85 We have reviewed the licensee's submittals dated January 9. April 8, and August 30, 1985, concerning an exemption requested for alternate shutdown capability for Fire Area 34B as required in 10 CFR 50 Appendix R. Fire Area 348 is the upper electrical penecration room and contains safe shutdown motor control centers and associated cables. This fire area' has been divided by a three-hour rated fire barrier into Fire Areas 34B-East and 348-West. In Fire Area 34B-West, the redundant backup pressurizer heater power feeder cables do not meet the separation requirements of Appendix R,Section III.G.2.

In addition, a fire in this fire area could result in spurious opening of a' PORV.

In the procedure developed by the licensee for a fire in Fire Area 34B-West, the first operation is for an operator to isolate the FORY by openinD a breaker and thereby teminating the LOCA. The safe shutdown procedure requires only two operators and therefore adequate personnel will always be available indepen-dent of the fire brigade.

! The reactor pressure, which is normally controlled by operation of the pres-l surizer heaters, will be controlled by controlling the flow rate of the i-auxiliary feedwater system (AFWS) in the event of the loss of all control to the backup pressurizer heaters. The AFWS and the controls to the AFWS to con-trol reactor pressure are currently available and no modifications are required.

No repairs are required for systems or equipment needed to achieve cold shut-down. The use of the AFWS as an alternative shutdown method for reactor pressure control has been previously reviewed and found acceptable in our SE for Fort Calhoun dated November 17, 1980 for a fire in the control room and cable spreading room.

Based on the above, we conclude that the alternate shutdown capability in the event of a fire in Fire Area 348-West is acceptable.

8511190430 851104 4

PDR ADDCK 05000285 F PDR

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