ML19208B468

Ro:On 790517,local Leak Rate Test of RHR Pump B Suction Torus Isolation Valve E11-F004B Showed Valve to Be Leaking in Excess of Specified Criteria.Valve Motor Operator Adjusted

ML19208B468
Person / Time
Site:	Hatch
Issue date:	08/29/1979
From:	Manry M GEORGIA POWER CO.
To:
References
PM-79-801, NUDOCS 7909200372
Download: ML19208B468 (4)

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N accrgia Power

. August 29, 1974 PM-?Q-801 PLANT E. I. HATCH Docket No. 60 7?1 Special Renort on RHR Puno Suction Torus Isolation Valve E11-F004B

• Mr. James P. O'Reilly Director of Inspection and Enforcement Region II O p' 'h p' D Suite 3100 bdj 101 Marietta Street Atlanta, Georgia 30302 p[D),- @ T, '

Dear Sir:

wUlt;0 L b On May 17, 1979, with the reactor in re fue li ng , a Local Leak Rate Test (LLRT) of the RHR nuno "B" suction t o rta s isolation valve E11-F0048 was performed per HNP 1 105?. This test shoued the valve to be leaking in excess of specified criteria frefer to LER 50-321/1070 033). Following cor-ective action (lapped seat eings, laoped gate, and adjusted the valve's motor operator -

see MR #1 79-2423), the valve was satisfactorily retested on July 26, 1979.

On August 12, 1070, the " B loop of the RHR svstam was placed in service in the shutdown cooling mode of operation, and the -

. reactor vessel level was observed to staat dropoing.

Investication showed that if the E11-F065n valve was closed, then the reactor vessel water level vould stabilize. Thus, the E11-F0049 and/or the E11-F0309 valves were leaking. On August 13, 1079, the "B" RHR pumo was run torus to torus in an attempt to flush the seat of the E11-F00hB valve; however, this had no a p p re c i.a b l e effect on the leakage. On August 14, 1979, the E11-F0309 (relief valve) was removed and bench-tested satisfactorily. Thus, the E11-F004R valve was determined to be leaking.

The LLRT performed on the E11-F00hB valve on July 26, 1079, was performed in the direction that it would have to prevent leakage post-LOCA, f.e., fron the inside of primary containcient outward; the 1.eaka.ge now exisiting for the E11-F00h9 valve is in the occosite direction, i.n., back towards contat.nnent. This leakage oath f"om the reactor vessel to the nucoression chamber / torus) oniv exists when the "B" RHR oump is in the shutdown cooling m o(i e of operation.

Thut. it was decided that the leakage or the valve represented no condition that would oreclude normal ocaration.

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he decision w19 then nad. to peaform a new LLRT on the 311-F0039 valve in order to ensure that the crimary containment l a t e r,"i t y of the valve still existed.

Thus, on August 14, 1970, a LLRT of the valve was performed.

The a e s u '. t s of this test showed the valve to be Icaking less than the accentance#

criteria soecified by the Technical Specification a ntf: 10CFR50 accendix J (.60La overall l e a'c a g e for all tvoe 9 and *type C LLRTs, and the leakage of the valve shall b'e 109 enou'dh such that the seal. water inventory of the valve is sufficient for 30 days - the seal water inventorv for the E11-F00hB valve is the torus). However, the valve leak rate was judged to be excessive by plant personnel and a deviation "coort (#1 70 126) was waitten saying that the E11-F00h8 valve had failed the LLRT. It was determined by the Plant 9eview Board that a Licensee Event Reco"t was not requiaed since the applicable Technical Specification and 10CFR50 apoendix J aceeotance criteria had been satisfied; houever, it was decided that a special reoort be written due to the sequence of events.

F o l. l ow i n st maintenance on the valve (tightened fou" bolts on the valve's notor ooerator - MR #1-70 h741), a satisfactory LLRT was performed on August 16, 107o.

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