ML20064D451
| ML20064D451 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 10/30/1978 |
| From: | Finfrock I JERSEY CENTRAL POWER & LIGHT CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7811070105 | |
| Download: ML20064D451 (1) | |
Text
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Jersey Central Power & Light Company
. 3 =.;
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Maatson Avenue at Punch Bowl Ros.d 2 (.d f l,.m...-.
Morristown, New Jersey 07960 (201)455-8200 October 30, 1978 Director Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Sir:
Subject:
Oyster Creek Nuclear Generating Station Docket No. 50-219 Failure of Control Pod to Fully Insert on Scram Signal 4
Your letter of September 6,1978, requested information concerning the failure of control rods to fully insert on a scram signal.
Our records show that there was one such occurrence at the Oyster Creek 1
Station during the calendar year 1977.
Subsequent to a scram on December 3, 1977, control rod 34-31 was noted to be at position "02",
six inches from fully inserted.
Follow up action, per procedure, was to fully insert the rod using normal drive pressure.
Review of the regular CRD stall flow data showed drive 34-31 to have a high stall flow; therefore, it was concluded that this event was caused by worn stop piston seals, as discussed in the General Electric Service Information Letter
[SIL 52, Supplement 1) issued in March 1974 Due to the high stall flow the drive from control rod 34-31 was replaced in September as part of scheduled maintenance during the current refueling outage.
Since this type event is not considered to have significant safety implications, no special effort has been made to record or report them beyond that givw to other plant events which are normally recorded for operations history or maintenance purposes.
In light of your interest, our personnel will be directed to ensure that any such events be recorded to enhance recovery of the information.
The foregoing provides the information you requested.
Should you need the additional data for the calendar year 1978, we will provide it upon request.
Very truly yours, I5Ull l
\\
Ivan R. Fi froc, Jr.
Vice President la 781107 o I o >-
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i JerntCentral Power & Leht Companos a Member of the General Pubhc Utihties System