ML19330A885
| ML19330A885 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 07/21/1980 |
| From: | Mroczka E NORTHEAST UTILITIES |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-17, MP-1-1569, NUDOCS 8007290697 | |
| Download: ML19330A885 (2) | |
Text
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P.O. 00X 270 NEj[OE,Ne$5~m.
HARTFORD CONNECTICUT 06101
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1 July 21, 1980 I
MP 1569 i
Mr. Boyce H. Grier
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Director, Region 1 i
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406
Reference:
Provisional License DPR-21 f
Docket No. 50-245
Dear Mr. Grier:
This letter provides information requested by your office previously reported in our response to Bulletin 80-17.
It is intended this information letter will provide additional detail of our test finding of item 2j of the subject bulletin.
l i
The test of the time delay was performed utilizing the opposite j
side of a form
'C' contact that is actually used in the circuit.
Both sides of the form
'C' contact are mechanically connected so that they both change state at the same time.
An isolated power supply and an additional relay were connected to the opposite side of the form
'C' contact to trigger a timing device.
During the manual scram test, because of an abnormal i
time delay, an investigation revealed a test connection wiring error.
The wiring was corrected and the automatic scram results showed approximately seventeen seconds for each of the two time delay relays.
i Further discussion revealed that a scram could be reset in less than seventeen seconds.
A hand over hand wire check and an add-4 itional functional test of the circuit showed that the contacts that were to provide the time delay were bypassed with wiring.
ll As a result, although the delay contact functioned themselves, they provided no time delay.
Research showed that this circuit ll was added during the unit startup test program.
Although con-trol wiring diagrams and elementary diagrams were correct, the panel and wiring list were incorrect.
4 4 The wiring was corrected and the following functional test performed:
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. i The relay that energizes the time delay relay was actuated by hand (normally it is energized as the backup scram valves are' energized).
The scram reset selector switch was then actuated.
The scram could not be reset for a period of approximately seventeen seconds.
Thus proving that time delay feature func-tioned properly.
Very truly yours Northeast Nuclear Energy Co.
W EJM/RJH:fdd E. J. Mroczka Station Superintendent i
Director, Office of Management Informac. ion and Program Control cc:
J. Stetz i
MP-1 File 1.4.6.4 I
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