ML20082C782

Ro:On 831015,instrument Air to Piping Penetration Room & Containment Inadvertently Isolated,Causing Letdown Line to Isolate & Charging Line to Open Fully.Caused by Improper Valve Assembly.Valve Repaired

ML20082C782
Person / Time
Site:	Farley
Issue date:	11/14/1983
From:	Clayton F ALABAMA POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 8311220201
Download: ML20082C782 (2)

Text

_______ ___ __ ____ __ . _ _ _ _ _ _ _ _ _ _ _ _ _ _

Milling Addrzes Alabama Power Company 600 Nortn 18th Street Post Office Box 2641 Birmingham, Alabama 35291 Telephone 205 783-60S1 A F. L. Clayton, Jr.

Senior Vice President Flintridge Building A9:38 AlabamaPower tre sourmm elec:nc systsm November 14, 1983 ,

Docket No. 50-364 I l l t

i Mr. J. P. O'Reilly U. S. Nuclear Regulatory Commission  ;

Region II 101 Marietta Street, N.W. l r

Suite 3100 Atlanta, GA 30303 ,

SUBJECT:

J. M. Farley Nuclear Plant Special Report - Unit 2  !

I

REFERENCE:

Technical Specification 3.4.10.3 l r

Dear Mr. O'Reilly .

l This special report is being submitted in accordance with Technical I Specification 3.4.10.3 action statement (c) to report the nitigation of a "

Reactor Coolant System pressure transient by the RHR relief valves.

On 10-15-83, Farley Nuclear Plant - Unit 2 was in Mode 5, with the RCS water solid (i.e. no pressurizer steam bubble), in preparation for 'startup following the Cycle II-III refueling outage. At 1415, instrument air to the  ;

piping penetration room and the containment was inadvertently isolated caus- ,

ing the letdown line to isolate and the charging line to open fully with one '

charging pump in operation. This resulted in an RCS pressure excursion to slightly more than 700 psig (at an RCS temperature of between 170*F and 175*F) causing the A train RHR pump suction relief valve to lift. The B train RHR suction valves had been closed to allow repair of the B RHR pump motor. The A train RHR suction relief did not limit the transient as designed and the charging pump was secured allowing the pressure to be  ;

restored. i l

Since charging had been secured for the previous occurrence, the Reac-tor Coolant Pumps had also been secured. It was anticipated that a second RCS pressure excursion would occur when restarting the first RCP. Plant conditions were established to minimize this transient and the 2B RCP was restarted at 1816 on 10-15-83. The transient caused the A' train RHR relief to lift with the pressure excursion being limited to 480 psig. RCS pressure was restored to 400 psig and no further pressure transients occurred.

--gC 8311220201 831114 PDR ADOCK 05000364 S PDR j[b pt t 0 m

(

l . :f*

Mr. J. P. O'Reilly November 14, 1983 Page Two Although the operability of the A train RilR relief valve had been verified by test inmediately following its last previous dicassembly and on two additional times since then, inspection of the valve subsequent to the pressure transient revealed that the reason for the higher than expected pressure transient was improper assembly of the valve. The valve was repaired, tested and returned to service.

The inadvertent isolation of instrument air was caused by an error in job planning. The job was replanned and successfully executed.

These events were evaluated by APCo and Westinghouse. These evaluations determined that no ASME III Appendix G limits were exceeded and that the RCS integrity was not challenged by these transients.

Yours very truly, q l F Clayton, Jr. I FLCJ r/KWM:nac/G-20 xc: File i

t

. ,, ,-