05000440/FIN-2015003-03
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Finding | |
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| Title | LICENSEE-IDENTIFIED Violation |
| Description | During a review of items entered in the licensees CAP, the inspectors identified that corrective action item (CR 201416769) documented direct and root causes for the reactor scram that occurred on November 7, 2014. The inspectors reviewed the root cause analysis and the corrective actions taken to prevent recurrence. The direct cause of the event was injection of a false feed flow runback signal, caused by the redundant reactivity control system (RRCS) self-test feature, into the digital feedwater control system DFWCS) which caused both contacts in the A and B divisions to close simultaneously, thus actuating a real feedwater runback. The licensee determined that the design was not adequate to prevent this event from occurring and that the root cause of the event was a latent design flaw from the original digital upgrade design package. The latent design flaw was identified by the licensee as a violation of 10 CFR 50, Appendix B, Criterion III, Design Control, which requires in part, design control measures for verifying or checking the adequacy of the design. The corrective actions, which consisted of physical modifications to plant equipment, were previously reviewed by inspections conducted during the refueling outage, March and April of 2015, and documented in Perry Integrated IR 2015002. The inspectors evaluated the licensee-identified violation using IMC 0612, Appendix B, Issue Screening, and determined that the deficiency was more than minor because it was associated with the Initiating Events Cornerstone attribute of design control and adversely 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. The inspectors further evaluated the issue in accordance with IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, dated June 19, 2012, and determined that the safety significance of this event was very low because, in accordance with the initiating events screening questions, all safety systems functioned as designed and the scram was not complicated. This issue is also discussed in Sections 4OA3.1 and 4OA7. |
| Site: | Perry  |
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| Report | IR 05000440/2015003 Section 4OA7 |
| Date counted | Sep 30, 2015 (2015Q3) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | Licensee-identified |
| Inspection Procedure: | |
| Inspectors (proximate) | J Beavers J Nance M Kunowski M Marshfield T Briley T Go J Seymour |
| Violation of: | 10 CFR 50 Appendix B Criterion III, Design Control |
| INPO aspect | |
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Finding - Perry - IR 05000440/2015003 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Perry) @ 2015Q3
Self-Identified List (Perry)
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