05000324/FIN-2009002-04
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Finding | |
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| Title | Unauthorized Maintenance Results in Loss of Shutdown Cooling (Section 1R20) |
| Description | A self-revealing Green NCV of TS 5.4.1, Procedures, was identified when the licensee changed the position of 2-E11-F009, the shutdown cooling (SDC) inboard suction throttle valve, without following a procedure. On March 26, Unit 2 was in Mode 5 in a refueling outage with the reactor refueling cavity flooded and fuel pool gates removed. Decay heat removal was being provided by protected systems, RHR loop B and supplemental spent fuel pool cooling. ADM-NGGC-0104, Work Management Process, states the maintenance that has an impact on system operation must be performed according to written instructions. Contrary to this requirement, a maintenance technician working without written instructions, operated the 2-E11-F009 valve locally in the drywell in the close direction, tripping the only operating RHR pump due to an electrical interlock. The licensee restored the RHR system to operation and entered the issue into their corrective action program. The operation of 2-E11-F009, the shutdown cooling (SDC) inboard suction throttle valve, during a maintenance activity was identified as a performance deficiency. The finding is more than minor because it affects the human performance attribute of the Initiating Events cornerstone and the objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. The inspectors evaluated this finding using Attachment 1 of IMC 0609, Appendix G, Shutdown Operations Significance Determination Process. This finding is of very low safety significance because the finding did not represent a loss of control and did not require quantitative assessment per Checklist 7 of Attachment 1 to IMC 0609, Appendix G. Specifically, the reactor time-to-boil during this event was approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> and RHR was restored in 17 minutes. Additionally, during the time that RHR was secured, the supplemental spent fuel pool cooling system provided sufficient decay heat removal. The finding has a cross-cutting aspect of human error prevention, as described in the Work Practices component of the Human Performance cross-cutting area because maintenance supervision and the maintenance technician failed to follow the stations policy for work on protected train equipment and use the human error prevention tools associated with the protected train concept. (H.4(a)). (Section 1R20) |
| Site: | Brunswick  |
|---|---|
| Report | IR 05000324/2009002 Section 1R20 |
| Date counted | Mar 31, 2009 (2009Q1) |
| Type: | NCV: Green |
| cornerstone | Initiating Events, Mitigating Systems |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71111.2 |
| Inspectors (proximate) | A Nielsen G Kuzo R Chou R Musser G Kolcum K Ellis B Davis M Corsey R Jackson |
| CCA | H.12, Avoid Complacency |
| INPO aspect | QA.4 |
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Finding - Brunswick - IR 05000324/2009002 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Brunswick) @ 2009Q1
Self-Identified List (Brunswick)
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