ML20198K422
| ML20198K422 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 05/21/1986 |
| From: | Alexich M INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| AEP:NRC:0985, AEP:NRC:985, NUDOCS 8606040023 | |
| Download: ML20198K422 (2) | |
Text
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.g - ~4 INDIANA & MICHIGAN ELECTRIC COMPANY P.O. BOX 16631 COLUMBUS, OHIO 43216 May 21, 1986 AEP:NRC:09f5 Donald C. Cook Nuclear Plant Unit Nos. I and 2 Docket Nos. 50-315 and 50-316 License Nos. DPR-58 and DPR-74 PROTECTION SET OPERABILITY Mr. James G. Keppler, Regional Director U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137
Dear Mr. Keppler:
This is to inform you of a procedure deficiency which was discoveted at the D. C. Cook Plant. Although we have determined that this is not reportabic under existing regulations, the potential for having operated outside the Technical Specifications did exist; thus, we are informing you of the condition.
During surveillance testing of the reactor protection logic system, the train being tested is deactivated by means of the " input errer inhibit" switch.
This switch is located on the semi-automatic test panel in the train, and its use inhibits reactor trips from the train being tested. When the tests are completed, the " input error inhibit" switch is returned to normal, and the reactivated train is tested to ensure that the-switches' contacts have closed.
While procedures ensure the positioning of the switch in the correct position following the test, four procedures did not require this additional precaution of testing to ensure that switch contacts had actually closed.
Following the discovery, the procedures were modified to include the required check, and an investigation into the potential consequences was initiated.
During the investigation, it was determined that there are at least forty Reactor Trip System surveillance tests which will provide verification that the " input error inhibit" switch is correctly positioned.
Each of these tests is scheduled to be conducted monthly, and a portion of them are conducted every week. Ilad a malfunction in the
" input error inhibit" switch occurred, it would have been very quickly identified at the beginning of any one of these forty surveillance tests and corrective action would have been taken.
B606040023 860521 PDR ADOCK 05000315 S
PDR tY x esi
Mr. James G. Keppler AEP:NRC:0985 This document has been prepared following Corporate procedures which incorporate a reasonable set of controls to insure its accuracy and completeness prior to signature by the undersigned.
Very truly yours,
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f M. P. A exich Vice President hj."
cm cc:
John E. Dolan W. G. Smith, J r. - Bridgman R. C. Callen G.
Bruchmann G. Charnoff NRC Resident Inspector - Bridgman e