05000269/FIN-2009006-01
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Finding | |
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| Title | |
| Description | A self-revealing, non-cited violation (NCV) of 10 CFR 50 Appendix B, Criterion III, Design Control, was identified for failure to provide sufficient margin between the peak discharge pressure of the low pressure injection (LPI) system and the relief valve setpoint for the Unit 3 B-train LPI cooler (3LP-37). This resulted in the inadvertent opening of 3LP-37 during LPI startup for decay heat removal on April 25, 2009. The licensee entered the issue into the corrective action program and revised the applicable operating procedure to provide additional margin during LPI startup for decay heat removal. The failure to provide sufficient margin between the LPI relief valve set point and the peak discharge pressure of the LPI system upon startup was a performance deficiency. The finding was more than minor because, if left uncorrected, it would have the potential lto lead to a more significant safety concern, specifically for loss of inventory if the relief valve failed to reseat. Additionally, the finding was associated with the Initiating Events cornerstone objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions during shutdown, primarily inventory control. The finding was of very low safety significance (Green) because it met the availability requirements set forth in IMC 0609, Appendix G, Shutdown Operations SDP, which verified that the licensee was maintaining an adequate mitigation capability for shutdown operation. The cause of the finding had a cross-cutting aspect in the area of human performance. It was directly related to the licensee not conducting effectiveness reviews of safety-significant decisions to verify the validity of the underlying assumptions, identify possible unintended consequences, and determine how to improve future decisions aspect of the decision-making component. Specifically, licensee calculation OSC-5616, reviewed and revised in 2008, identified a possible unintended consequence that 3LP-37 could lift during LPI pump start. This was not incorporated into plant procedures to prevent future relief valve lifts. Additionally, with the assumption that the relief setpoint for 3LP-37 was low, the licensee started the LPI system during the3EOC24 outage under the same conditions that 3LP-37 lifted during the 3EOC23 outage |
| Site: | Oconee  |
|---|---|
| Report | IR 05000269/2009006 Section 4OA2 |
| Date counted | Sep 30, 2009 (2009Q3) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | M Checkle M King G Ottenberg R Cureton M Pribish C Kontz D Merzke L Suggs |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
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Finding - Oconee - IR 05000269/2009006 | |||||||||||||||||||||||||||||||||||||||||||
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Finding List (Oconee) @ 2009Q3
Self-Identified List (Oconee)
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