ML19347C781
| ML19347C781 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 05/27/1975 |
| From: | CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| References | |
| AO-14-75, NUDOCS 8102170099 | |
| Download: ML19347C781 (1) | |
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s ABNORMAL OCCURRENCE REPORT Big Rock Point Plant 1.
Report No: A0-lh-75, Docket 50-155 2a.
Report Date:
May 27, 1975 2b.
Occurrence Date: May 26, 1975 3.
Facility: Big Rock Point Plant k.
Identification of Occurrence: Containment ventilation supply valve leak test excessive.
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5 Condition Prior to Occurren~ce: Plant in cold shutdown for modification activity associated with A0-1-75
'6.
Description of Occurrence: During a special monthly test of the ventil-ation valve leak rate, excessive leakage was noted during the test based on pressure gauge readings. The special test was being conducted to verify corrective action that was applied as a result of A0-8-75 des-cribed in our letter of March 31, 1975 7
Designation of Apparent Cause: Investigation revealed that the actuation
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mechanism bolted fitting on CV 4097 had shifted due to rotational stresses during previous valve operations. This prevented the disc from rotating to its full travel position.
8.
Analysis of Occurrence: Leakage was excessive on only one of two valves in series and thus does not represent a breach of containment integrity.
9 porrective Action: The valve actuation mechanism was repaired and the valve was test operated and leak tested satisfactorily. Tne actuation fitting was punch marked for future reference. Monthly leak testing and fitting mark checks will be made for a period of at least three months to monitor the corrective action.
10.
Failure Data: Reference A0-8-75 described in our letter of March 31, 1975 Valve manufacturer - Allis-Cnalmers, 24" Model 50 FR, Streamseal.
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