ML20083R161

Ro:On 720615 & 720616,while Performing Surveillance Check, MSIV NS03B Found Leaking,Exceeding Max Limit.Investigation Initiated

ML20083R161
Person / Time
Site:	Oyster Creek
Issue date:	06/26/1972
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20083R159	List: ML20083R161
References
NUDOCS 8303310480
Download: ML20083R161 (2)

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h Light Company M ADISoN AVENUE AT PUNCH BOWL RO AD e MoRRISTOWN, N.J. 07960 e 539 611 f June 26, 1972 ' , -

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Mr. A. Giambusso hIY3 4 i Deputy Director for Reactor Projects Directorate of Licensing 3

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United States Atomic Energy Commission L' M ' e ["

Washington, D. C. 20545 4 .g h/ ~

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Dear Mr. Giambusso:

Q

Subject:

Docket 50-219 Oyster Creek Station Surveillance Test Failures The purpose of this letter is to report several surveillance test failures that have occurred at the Oyster Creek Station during the past.several days.

On June 15, 1972 at 6:16 p.m., the containnent spray system was being set up to simulate a loss-of-coolant accident in conjunction ~

with a loss of off-site power. The test that was planned was an auto-w Dactuation test of diesel generator no. 1. In this test procedure, a s, simulated high drywell pressure signal is applied to drywell pressure switches IP15 "A" and "C" and RV46 "A" and "C". This starts containment f spray system I and core spray system I puinps. When this signal was

.# applied and emergency service water pump "A" started, the rubber expansion

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f joint, which joins the pump to the discharge pipiEg7 ruptQred.7E'pumpt was manually stopped from the Control Room and the "B" emergency service

,water pump was manually started to supply the load for the diesel' generator test. A temporary spool piece has been installed to make the "A" emergency service water pump operable. There was no safety significance associated /

with this event since the reactor was shutdown in the " REFUEL" mode and

, h)# primary containment integrity was not required.

At 0300 on June 16,1972, NS03B was tested for leakage as

) required by Technical Specification 4.5.E.1. The leakr e was measured to be approximately 100 SCFil or, 50% of L 20 . NS03i,was previously M observed to have no detectable leakage durin(g t )he hydrostatic test applied to the reactor vessel on June 11, 1972. The pilot valve stem l 0 was found to be 38 mils out of alignment which could possibly cause /

F g improper seating of the pilot stem or. the main valvg -plug. No indi-cation of foreign material under the valve seating surfaces or. damage y to these surfaces could be found. The valve was disassembled and the

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'* d b Mr.*A. Giambusso Page II June 26, 1972 pilot stem'was removed and straightened. Both seating surfaces were also lapped while the valve was disassembled. Following reassembly of NS03B, the 20 psig pressure test showed no detectable leakage (i.e. <0.1 SCFH). The testing of main steam isolation valve NS03B was performed subsequent to the primary containment integrated leak rate test which was completed on June 15, 19,7L The results of the primary containment leak rate test indicate that main steam isolation ,

valve NSO4B, in the same line, did not have excessive leakage. In addition, local leak rate tests on NSO4B indicated a leak rate of 1.26 SCIH, well below 5% of Lto ( 2_0) . An independent consultant is currently investigating the long-term suitability of the main steam isolation valves, and the results of this investigation and any subsequent recommended modifications will be reported as soon as they are available.

We are enclosing twenty-five copies of this letter.

Very truly yours,

'Gy) trl ,

Ivan R. Finfr,ck, Jt.

Manager, Nuclear Generating Stations IRF/pk Enclosures cc: Mr. J. P. O'Reilly, Director Regulatory Operations, Region I i

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