05000387/FIN-2011002-02
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Finding | |
|---|---|
| Title | Inadequate Corrective Actions Result in Loss of Drywell Cooling and Downpower |
| Description | A self-revealing Green finding of NDAP-QA-0702, Action Request and Condition Report Process, Revision 27, was identified when inadequate corrective action from the July 2010 flooding event resufted in endbell leakage from the \'1A\' Reactor Building (RB) chiller during a post-mpintenance test (PMT) that wetted and tripped the redundant \'1B\' RB chiller. The logs of both chillers resulted in elevated drywell temperatures and off-normal procedule entries, and also required a power reduction of approximately 40 percent rated thermal power (RTP). PPL\'s corrective actions from this event included updating MT\'61t4-915, Torquing Guidelines, Revision 23, Section 8.4, Joints Using Elastomer Gaskets, to require a torque recheck after one hour. Another corrective action required that equipment work instructions include correction of any adverse sealing surfaces orf epoxy-coated flange faces identified. PPL entered this issue into their corrective action plan (CAP) as CR 1381 163. The finding was more than minor due to its adverse affect on the lnitiating Events cornerstone objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions during shutdown as well as power operations and was associated with its configuration control bnd equipment performance attributes. Specifically, the operating RB chiller\'s lineup and availability were impacted by being wetted and tripping during maintenance of the \'1A\' RB chiller and resulted in reactivity manipulations to control drywell parameters. The finding was evaluated in accordance with IMC 0609 Attachment 4, lnitial Screening and Characterization of Findings, and determined to be a transient initiator contributor. However, while the finding contributed to the likelihood of a reactor trip, it did not contribute to the likelihood that mitigation equipment or functions would not be available, and, therefore, screened as Green. The finding was determined to have a cross-cutting aspect in Pl&R area, CAP, for which a licensee thoroughly evaluates problems such that the resolutions address causes and extent of conditions. Specifically, following Unit 1 July 2010 internal flooding event, PPL did not thoroughly evaluate the problems of torque relaxation and coating irregularities such that corrective actions addressed the actual extent of cause and conditions. (P.1(c)) |
| Site: | Susquehanna  |
|---|---|
| Report | IR 05000387/2011002 Section 1R19 |
| Date counted | Mar 31, 2011 (2011Q1) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71111.19 |
| Inspectors (proximate) | E Dipaolo J Furia A Rosebrook P Finney J Tomlinson J Greives D Molteni |
| CCA | P.2, Evaluation |
| INPO aspect | PI.2 |
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Finding - Susquehanna - IR 05000387/2011002 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Susquehanna) @ 2011Q1
Self-Identified List (Susquehanna)
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