05000272/FIN-2013005-02
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Finding | |
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| Title | Performance Monitoring of Reactor Trip Breakers |
| Description | Inspectors identified an Unresolved Item (URI) concerning Maintenance Rule functional failure determinations of Unit 1 reactor trip breakers. PSEG commenced re-evaluating the equipment issues and entered the concerns in their CAP as 20634111 and 2064110. During the inspection period, inspectors selected the Unit 1 reactor trip breakers as a Maintenance Effectiveness inspection sample in accordance with IP 71111.12. The inspectors questioned PSEG concerning two notifications written on the 1B normal and 1A bypass reactor trip breakers that did not meet as-found acceptance criteria during semi-annual maintenance. Specifically, the 1B normal reactor trip breaker failed undervoltage (UV) trip time response and trip bar force criteria on December 11, 2012, and the 1A reactor trip bypass breaker failed the UV trip assembly degradation value on July 16, 2013. Within 15 days of these discoveries, in accordance with procedure ER-AA-310-1004, Maintenance Rule - Performance Monitoring, Revision 10, PSEG determined that both of these issues were not Maintenance Rule Functional Failures (MRFFs). The inspectors reviewed the Maintenance Rule aspects of these issues and developed concerns regarding the same. The inspectors questioned whether the breakers met the MRFF criteria. Specifically, one of the MRFF examples was failure to meet acceptance criteria in SC.MD-PM.RCP-0001, Reactor Trip Breaker Semi-Annual Inspection, Lubrication, and Testing, Revision 19, for trip bar force, UV trip bar force, ten times testing, and trip time response. The 1B normal reactor trip breaker issue matched the criterion. The 1A bypass breaker also met the criterion with the exception that it was covered by a separate maintenance procedure (SC.MD-PM.RCP-0003). The acceptance criteria for normal and bypass breakers were the same and the bypass breakers perform the same function of the normal breakers during their substitution. The 1B normal trip breaker evaluation stated that the apparent cause was due to insufficient lubrication of trip latch during prior preventive maintenance. The inspectors considered this a potential for the failure to be a maintenance-preventable functional failure (MPFF). The rod control system performance criterion (PC) was 6 MPFFs in 36 months. The inspectors considered this a high threshold for a component whose high risk function is to remove power from control rod drive mechanisms on valid manual or automatic trip signals. Since there are four breakers per unit that undergo semi-annual testing, an assessment of performance under 10 CFR 50.65(a)(1) would require a 25% failure rate that was also attributable to maintenance. The inspectors found no evidence that this issue was captured previously in PSEGs CAP. Finally, ER-AA-310-1003, Maintenance Rule - Performance Criteria Selection, Revision 6, directs that Maintenance Rule SSCs with a risk achievement worth (RAW) greater than 10 require both reliability and condition-monitoring performance criteria. The Unit 1 reactor trip breakers have a RAW on the order of 1200. Condition-monitoring PC did not exist and this had not been documented in PSEGs CAP. The inspectors presented these concerns to PSEG on December 20, 2013. During an inspector discussion with PSEG engineering on the issues, PSEG provided notification 20627747 written on October 30, 2013, which needed additional information to document the basis for the Maintenance Rule determination that included the two issues mentioned above. PSEG stated that this CAP item was written to revisit the MRFF determinations previously completed. The inspectors reviewed the notification and noted that 60 days later, the MRFFs had not been revisited, the assigned action was to enhance MRule screening vice a re-evaluation, and that it was due on December 20, 2014. Following inspector questioning, PSEG re-evaluated the issues and determined that the 1B normal reactor trip breaker had been an MRFF. PSEG is in the process of further evaluating the 1B normal breaker MRFF to determine whether it was a maintenance-preventable functional failure (MPFF). PSEGs re-evaluation of the 1A bypass breaker as an MRFF was that it was still not one based on the MRFF criteria currently written in specific to the reactor trip breaker procedure... and not the trip bypass breaker procedure. The inspectors pointed out that the MRFF criteria included a statement that said Functional failures include, but are not limited to... prior to the list. A URI was identified because additional NRC review and evaluation is needed to determine if the issue is more than minor and whether the issue of concern constitutes a violation. The inspectors need to review PSEGs ultimate determination of the MRFF and MPFF aspects of these breakers to determine if performance was being effectively controlled and monitored. The inspectors will also assess whether additional monitoring is warranted under 10 CFR 50.65(a)(1) and thus any violations existed of this criteria. As a result, this issue will be considered unresolved pending inspector review of the MRFF determinations and any consequent evaluations of causes and maintenance rule re-classification. Pending resolution of this issue and determination of any potential enforcement actions, this item is a URI. |
| Site: | Salem  |
|---|---|
| Report | IR 05000272/2013005 Section 1R12 |
| Date counted | Dec 31, 2013 (2013Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.12 |
| Inspectors (proximate) | K Young M Modes P Finney R Barkley R Nimitz A Defrancisco A Ziedonis D Silk G Dentel H Gray J Furia J Laughlin J Schoppya Patela Ziedonis E Burket G Dentel J Schoppy P Finney R Barkley |
| INPO aspect | |
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Finding - Salem - IR 05000272/2013005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Salem) @ 2013Q4
Self-Identified List (Salem)
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