05000286/FIN-2009007-01
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Finding | |
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Title | Degraded Grid Protection Time Delay Relay Exceeded Technical Specification Limits |
Description | The inspectors identified an NCV of very low safety significance of 10 CFR 50, Criterion XVI, Corrective Action, for Entergys failure to identify and correct a condition adverse to quality related to 480-Volt bus 3A degraded grid protection. Specifically, Entergy staff did not identify and implement adequate corrective actions to ensure the safety-related time delay relay, 62-1/3A, remained functional within its technical specification (TS) surveillance requirement (SR) acceptance criteria when it exhibited abnormal relay drift in October 2007. As a result, the relay drifted out of specification for a portion of the next surveillance period, which should have been reasonably avoided. Additionally, in November 2007, Entergy did not adequately evaluate past operability to determine if NRC reportability criteria per 10 CFR 50.73 were exceeded for the degraded relay condition that existed for a time longer than would be permitted by the TS action statement. Entergy entered the issue into the corrective action program as CR-IP3-2009-02664 and CR-IP3-2009-02773 which includes a final review of reportability by Entergy. The inspectors determined the finding is more than minor because it is associated with the equipment performance attribute of the Mitigating Systems cornerstone and affects the cornerstone objective of ensuring the reliability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). Specifically, the 480-Volt bus 3A degraded voltage safety-related time delay relay, 62-1/3A, was degraded and exceeded its TS SR acceptance criteria of 45 seconds during two consecutive surveillance tests. However, the inspectors determined the relay would perform its safety function with a worst-case time delay of 55.9 seconds for a non-safety injection (non-SI) degraded grid condition. The inspectors review determined this condition would not reasonably have prevented the relay from performing its function, allowing the 480V electrical bus 3A to swap its supply from the offsite grid to the on-site 31 emergency diesel generator prior to the loss or damage of supplied equipment. The inspectors determined the significance of the finding using IMC 0609.04, Phase 1 Initial Screening and Characterization of Findings. The finding was determined to be of very low safety significance (Green) because it was not a design or qualification deficiency; did not represent a loss of system safety function; and did not screen as potentially risk-significant due to external initiating events. The inspectors determined that this finding had a cross-cutting aspect in the area of problem identification and resolution within the corrective action program component because Entergy personnel did not thoroughly evaluate the problem such that the resolution addressed the cause. |
Site: | Indian Point |
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Report | IR 05000286/2009007 Section 4OA2 |
Date counted | Jun 30, 2009 (2009Q2) |
Type: | NCV: Green |
cornerstone | Mitigating Systems |
Identified by: | NRC identified |
Inspection Procedure: | IP 71152 |
Inspectors (proximate) | M Halter R Powell S Rutenkroger T Setzer |
CCA | P.1, Identification |
INPO aspect | PI.1 |
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Finding - Indian Point - IR 05000286/2009007 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Indian Point) @ 2009Q2
Self-Identified List (Indian Point)
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