05000263/FIN-2013004-01
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Finding | |
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| Title | Recirculation System Vulnerabilities Due to Inadequate Modification Review |
| Description | A self-revealed finding of very low safety significance occurred on August 27, 2013, due to the licensees failure to adequately review and control modification work. Specifically, the licensee failed to follow FP-E-MOD-07, Design Verification and Technical Review, when the review process did not ensure that a 13.8 kV switchgear modification was adequate and maintained all functions of the recirculation system. This led to the failure of plant personnel to land wires necessary to transmit breaker position signals to the recirculation speed control system and, as a result, the site failed to maintain the recirculation function to initiate runbacks in response to a condensate or feedwater pump trip. In addition, the inadequate modification left both recirculation pumps susceptible to spurious runbacks, and resulted in two inadvertent runbacks when operators were lowering flow on each pump. The licensee took action to lock the recirculation scoop tubes to terminate the inadvertent runbacks, initiated complex trouble-shooting and a root cause evaluation, and implemented a new modification to restore the recirculation system runback functions that were lost. The finding was more than minor because it was associated with the Initiating Events Cornerstone attribute of design control and affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the inadequate modification disabled the recirculation function to initiate runbacks after feed or condensate pump trips, and left both recirculation pumps susceptible to inadvertent runbacks. The inspectors utilized IMC 0609, Appendix A, and determined a detailed risk assessment was required because the finding involved the partial loss of a support system that contributes to the likelihood of, or causes, an initiating event AND affected mitigation equipment. Based on the Detailed Risk Evaluation, the senior reactor analysts determined that the finding was of very low safety significance. The inspectors concluded that this issue was cross-cutting in the Human Performance, resources area, because the modification development and review process failed to utilize complete, accurate, and up-to-date design documentation, procedures, and work packages. |
| Site: | Monticello  |
|---|---|
| Report | IR 05000263/2013004 Section 1R18 |
| Date counted | Sep 30, 2013 (2013Q3) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71111.18 |
| Inspectors (proximate) | A Dunlop K Riemer T Bilik C Brown K Stoedter P Voss J Corujo -Sandin S Bell D Oliver M Ziolkowsk |
| CCA | H.7, Documentation |
| INPO aspect | WP.3 |
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Finding - Monticello - IR 05000263/2013004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Monticello) @ 2013Q3
Self-Identified List (Monticello)
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