05000321/FIN-2009005-03
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Finding | |
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| Title | Failure to establish and perform preventive maintenance activities to replace aged electrolytic capacitors for Yokagawa controller power supply |
| Description | A self-revealing finding was identified for the licensees failure to establish and perform preventive maintenance activities to replace electrolytic capacitors as required per licensee procedure, NMP-ES-006, Predictive Maintenance Implementation and Continuing Equipment Reliability Improvement. As a result, this failure directly resulted in a Unit 1 manual reactor scram on November 22, 2008 (LER 05000321/2008-004). The licensee replaced the steam jet air ejector intercondenser cooling water control valve differential pressure controller (1N21-K088) failed power supply. This issue was documented in the licensees corrective action program as CR 2008111605. This performance deficiency was more than minor because it is associated with the Equipment Performance attribute of the Initiating Events cornerstone and affected the cornerstone objective to limit the likelihood of those events that upset plant stability and challenge critical safety functions during power operations, in that, on November 22, 2008 the 1N21-K088 power supply failed which led to a manual reactor scram for Unit 1. The significance of this finding was screened with NRC Inspection Manual Chapter 0609 Attachment 4, and since it contributed to an increase in the likelihood of a reactor trip and affected the reliability and availability of mitigating system equipment, a phase 2 SDP analysis was required. The phase 2 review of the Hatch pre-solved worksheet did not have an appropriate column to evaluate the finding, therefore a phase 3 significance determination process (SDP) analysis was required. The phase 3 SDP analysis was performed by a regional senior risk analyst (SRA), as a loss of main feedwater initiating event assessment using the NRCs Standardized Plant Analysis Risk (SPAR) model. The result was <1E-6 for conditional core damage probability and <1E-7 for conditional large early release probability, a GREEN finding. The dominant sequences were Anticipated Transient Without Scram (ATWS) sequences. The analysis assumed condensate remained available throughout the transient, and that main feedwater was recovered with a human error probability determined using the NRCs SPAR H methodology. The large early release frequency (LERF) risk was determined using the ATWS LERF multiplier from the Hatch phase 2 notebook. The inspectors determined this finding has a cross-cutting aspect in the Operating Experience component of the Problem Identification and Resolution area, because the licensee did not implement and institutionalize operating experience through changes to station processes, procedures, equipment, and training programs, in that, the licensee did not make changes to station processes when internal and external operating experience indicated similar electrolytic capacitors failures were occurring. (P.2(b)) |
| Site: | Hatch  |
|---|---|
| Report | IR 05000321/2009005 Section 4OA3 |
| Date counted | Dec 31, 2009 (2009Q4) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | B Caballero D Jones E Morris G Macdonald J Eargle P Niebaum S Shaeffer |
| CCA | P.5, Operating Experience |
| INPO aspect | CL.1 |
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Finding - Hatch - IR 05000321/2009005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Hatch) @ 2009Q4
Self-Identified List (Hatch)
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