ML20058L637
| ML20058L637 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 10/14/1976 |
| From: | Wachter L NORTHERN STATES POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEC-76-04, IEC-76-4, NUDOCS 9105300369 | |
| Download: ML20058L637 (1) | |
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NORTHERN STATES POWER COMPANY
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MIN N E A POU S. MIN N E SOTA 88401 l
r October 14,.1976 P
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i Mr. James C. Keppler Director - Region III Office of Inspection and Enforcement United States Nuclear Regulatory Commission.
799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
MONTICELLO NUCLEAR GENERATING PLANT j
Docket No. 50-263 License No. DPR-22 f
The following infomation is submitted in response to IE Circular 76-04:
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1.
The only two bypass switch malfunctions which have occurred at the Monticello Nuclear Generating Plant involved failures to bypass.
During preoperational testing (prior to 1971), a failure to bypass one IRM channel occurred. No record of corrective action exists j
for this malfunction.
In April, 1975, a failure to bypass an APRM channel occurred. The switch which malfunctioned was replaced with a new switch of identical design.
2.
In November, 1975, the wiring of the RBM bypass switch was revised as re.:ommended in General Electric's Service Letter 111, Revision 1.
Management memos were written to inform the operators of the potential problem and require that the proper bypass condition be verified by the panel 11ghts and/or computer whenever a bypass is initiated or removed. Au procedures that involve operation of the bypass switches were reviewed and revised, where necessary, to require the above verification. Thus, operability of the circuit is tested every time L
the witch is operated for surveillance. or maintenance.
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Yours very truly,
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9105300369 761014 g
. Wachter Vice President - Power Production and System Operation cc:
Mr. Victor Stello Mr. G. Charnoff Minnesota Pollution Control Agency Attention:
Mr. J. W. Terman f
OCT 101976
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