ML20084F892
| ML20084F892 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 12/13/1971 |
| From: | Finfrock I JERSEY CENTRAL POWER & LIGHT CO. |
| To: | Morris P US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| 5417, NUDOCS 8304210308 | |
| Download: ML20084F892 (2) | |
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Jersey Central Power & Light Company
'Ql M ADISON AVENUE AT PUNCH DoWL flo AD e MoR RIST oWN. N. J. 07960 e 533 -6111 December 13, 1971 X 4~~,
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3 Dr. Peter A. !iorris, Director Division of Reactor Licensing 3
United Stutes Atomic Enercy Commission
,j Unshington, D. C. 20545 l
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Dear Dr. Morris:
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Subject:
Oyster Creek Station Docket I!o. 50-219
&!ain Steam Isolation Valve I!S03B Leakage, On September 18, 1971, vhile the plant was being shut down for a scheduled outage, the Main Steam Isolation Valves were checked for closure times in accordance with Technical Specification require-ments.
The results were as follows:
I;S03A - 8.2 seconds IIS03B - 3.2 seconds IIS01.A - 6.9 seconds nS0hB - 7 9 seconds The Technical Specifications require the closure tires to be > 3 seconds and < 10 seconds (Section 4.5.I.2).
Valve US03B, while within Technical Specification limits, closed faster than desired. Upon inspection of the valve, it was observed that the hydraulic dannpot adjustment leg was leaking.
Approximately 3 pints of oil were added to the dashpot and repairs made to the leaking line.
D The Main Steam Isolation Valve leak tceting program was initiated on !!ovember 2,1971.
At this time, the Main Steam Lines were flooded; therefore, it was possible to test the outside yalves, US0hA cnd I;SchB. The leakr.gc tests indicated that valve liSOhA was tight (2.1 SCFH).
Valve I'SO4B was unable 'to be tested because the volume between valve I;S03B and US0hB could not be drained of water.
This was a clear indication of leakage past the seat of valve 11S033.
On UcVerber 5, 1971, the Main Stean Lines were drained and the reactor pressurized to 20 poig in order to co=ence testing on the 2 inner valves, US03A and I:303B.
A plot of reactor pressure versus tine on the pressurisation operation indicated that at least 1 valve in each steam line was tight due to the rapid pressurising rate.,
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Dr. Peter A. Morris Page II December 13, 1971 This in based on previous experience in attempting to pressurize the Valve US03A exhibited no reactor prior to testing the inner valvec.
detectable leakage as obcerved by the bubbler method for 15 minutes.
All of the Valve US03B had a meacured leakage rate of 110 SCFH.
(USO3A, US03B, UsohA, and UschB) were tected in the as-found valves condition following the September 16 shutdown.
Based un the above-mentioned repairc to US03B hydraulic The closure time was h.8 cylinder, the valve van cycled and timed.
seconds which van desirable. Another leak tent van performed on this valve.
The results indicated 10.2 SCFH leakage.
Since this value van slightly in excess of the new Technical Specification limit or 9 95 SCFH, the valve was disascembled to inspect the centing curfaces and ctem for damage.
Prior to dicacceably of US03B, a tent vac conducted on NSchB and a leakage of h.16 SCFH van measured, which van well within the Technical Specification requirements.
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Maintenance repair on USO3B involved straightening the ntem, which van 27 mills out of alignment, and lapping both the l
main neat and the pilot valve scat.
However, the seating curfaces The valvec did not appear to be denaged or indicate uneven vcar.
vere reassembled and cycled to ot)tain proper clocure time. HS03B vas then retected and exhibited negligible leakage.
Summaricing the test results, the indicated leak rates were as follovc:
NS03A
<0.1 SCFH US03B - <0.1 SCFH US0hB - =h.2 SCFH US0hA
=2.1 SCFH l
h11 of the above values naticry the Technical Specification leak t
rate criteria of lecc than 9 95 SCFH at 20 psig test pressure, i
Main Sten'a Isolation Valve NS03B vill be retcated at the l
next planned cold chutdcun; and in any event, no later than the next l
refueling outage (currently planned for April 1972).
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Twenty-five copiec of thic letter are encloced.
t Very truly yours,
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l Ivan R. Finfr /ek,
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Manager, I;ue. ear 'enerating Stationc IRF/pk cc: Mr. J. P. O'Reilly, Director A iem-_rm enmniinnee Recion T