05000244/FIN-2009008-01
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Finding | |
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| Title | Failure to Preclude Recurrence of a Significant Condition Adverse to Quality Associated with the Turbine Driven Auxiliary Feedwater Pump Governor Control Valve |
| Description | A self-revealing apparent violation (AV) of 10 CFR 50, Appendix B, Criterion XVI, Corrective Actions, was identified for the failure to preclude recurrence of a significant condition adverse to quality (SCAQ) associated with the Turbine Driven Auxiliary Feedwater (TDAFW) pump governor control valve. Specifically, after identifying corrosion of the governor control valve stem in April 2005, Ginna did not take adequate corrective actions to preclude the recurrence of corrosion which led to the binding of the governor control valve and failure of the TDAFW pump on July 2, 2009.In addition, the inspectors concluded that governor control valve stem binding was the likely cause of the failure of the TDAFW pump on May 26, 2009. The overspeed trip of the TDAFW pump on May 26, 2009, was originally determined by Ginna to be failure of the governor control system relay valve. Governor control valve stem corrosion is a SCAQ because corrosion of the stem can lead to governor control valve stem binding and failure of the TDAFW pump as discussed in NRC Information Notice (IN) 94-66: Overspeed of Turbine-Driven Pumps Caused by Governor Valve Stem Binding and other related industry operating experience documents. Immediate corrective actions included entering this condition in the corrective action program (CAP), conducting a root cause analysis (RCA), replacing the governor control valve stem, and conducting weekly monitoring of the governor control valve during surveillance testing to identify any potential for stem binding. In addition, corrective actions included a follow-up inspection of the governor control valve during the fall 2009 refueling outage. Ginna will continue to monitor the governor control valve under an enhanced TDAFW surveillance program to ensure TDAFW pump operability. The finding is more than minor because it is associated with the equipment performance attribute of the Mitigating System cornerstone and affects the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, stem corrosion caused binding of the governor control valve and led to the failure of the TDAFW pump. This finding was assessed using IMC 0609 and preliminarily determined to be White (low to moderate safety significance) based on a Phase 3 analysis with a total (internal and external contributions) calculated conditional core damage frequency (CCDF) of 8.6E-6.This finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Corrective Action Program, because Ginna did not implement a corrective action program with a low threshold for identifying issues completely, accurately, and in a timely manner commensurate with their safety significance P.1(a} per IMC 0305.Specifically, Ginna did not identify issues associated with corrosion of the governor control valve within the corrective action program |
| Site: | Ginna  |
|---|---|
| Report | IR 05000244/2009008 Section 4OA5 |
| Date counted | Sep 30, 2009 (2009Q3) |
| Type: | Violation: White |
| cornerstone | Mitigating Systems |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 93812 |
| Inspectors (proximate) | K Kolaczyk S Kennedy C Cahill G Dentel J Breamg Dentelj Bream K Kolaczyk S Kennedy |
| Violation of: | 10 CFR 50 Appendix B Criterion XVI |
| CCA | P.1, Identification |
| INPO aspect | PI.1 |
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Finding - Ginna - IR 05000244/2009008 | |||||||||||||||||||||||||||||||||||||||||
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Finding List (Ginna) @ 2009Q3
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