05000461/FIN-2013005-01
Finding | |
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| Title | Failure to Evaluate Failures of Individual Safe Shutdown Emergency Lighting Units for Maintenance Preventable Functional Failures and Repetitive Maintenance Preventable Functional Failures |
| Description | The inspectors identified an unresolved item (URI) regarding the licensees failure to evaluate failures of individual safe shutdown emergency lighting units for maintenance preventable functional failures and repetitive maintenance preventable functional failures in accordance with the licensees Maintenance Rule implementation procedures. During review of the licensees Maintenance Rule program, the inspectors identified that the licensee only used condition monitoring criteria to demonstrate effective maintenance of the plants safe shutdown lighting system. The licensee limited this system to fewer than 9 condition monitoring failures on 33 emergency lighting battery packs at 264 quarterly testing demands in a rolling 24 month period, which was equivalent to a 3 percent failure rate, to demonstrate effective maintenance of the system. The licensees definition of a condition monitoring failure for the battery packs is the failure of any emergency lighting battery pack to provide the required illumination. However, the licensee does not have any established reliability performance criteria to monitor for functional failures of this system. The licensees process for evaluating condition monitoring failures and reliability failures is different. For reliability failures, step 4.5.5 of ER-AA-310, Implementation of th
Maintenance Rule, directs the licensee to evaluate whether a Maintenance Rule Functional Failure (MRFF) has occurred. If one has, the procedure directs the license to determine if the MRFF is a Maintenance Preventable Functional Failure (MPFF), an if so, determine if the MPFF is a Repetitive Maintenance Preventable Functional Failur (RMPFF). If a system has a RMPFF, the procedure directs the licensee to perform a evaluation to determine if maintenance is effective, and if not, the licensee is required t monitor the system under 10 CFR 50.65(a)(1). Conversely, condition monitoring failure are not evaluated for any of these criteria, and therefore do not get evaluated for RMPFFs which require (a)(1) evaluations. In NUMARC 93-01, Industry guideline for Monitoring the effectiveness of Maintenance at Nuclear Power Plants, Revision 4A, a MPFF is defined as, an unintended event or condition such that a SSC within the scope of the rule is not capable of performing its intended function and that should have been prevented by the performance of appropriate maintenance actions by the utility. The inspectors identified that there are areas of the plant that are required for safe shutdown activities that have only one or two safe shutdown emergency lighting units installed in the area. Under the licensees current Maintenance Rule program, each individual lighting unit failure would be considered a condition monitoring failure and would not be evaluated for MPFFs o RMPFFs. The inspectors need to determine whether a failure of one or more lights in a area such that the area no longer has functional installed safe shutdown lighting shoul be considered a Functional Failure subject to a MPFF review. The licensee informed the inspectors that the licensees condition monitoring criteria was developed based on a memo from the licensees corporate office (formerly ComEd) that was developed in 1999 in response to a NRC violation at Braidwood Station. The memo recommended that each station implement condition monitoring performance criteria because, the NRC pointed out that by measuring only reliability, Braidwood was allowing important functional failures to occur without requiring moving the system to (a)(1), and thus not repairing the attendant (a)(1) action plan. In response to this memo, the licensee and other Exelon (ComEd) stations implemented only Condition Monitoring for their emergency lighting. During the inspectors review, however, the inspectors identified that some other Exelon stations, including Braidwood, perform both reliability and condition monitoring. The inspectors need to determine whether it is appropriate for the licensee to perform condition monitoring without reliability monitoring on the Safe Shutdown Emergency Lighting system when step 6 of Attachment 1 to the licensees procedure ER-AA-310-1003, Maintenance Rule Performance Criteria Selection, states, Condition monitoring augments existing criteria ([Availability Performance Criteria], [Reliability Performance Criteria], Plant Level), where the existing monitoring may be insufficient. The issue is categorized as an URI pending licensees completion of a revised evaluation and the NRCs review of it (URI 05000461/20013005-01, Failure to Evaluate Failures of Individual Safe Shutdown Emergency Lighting Units for Maintenance Preventable Functional Failures and Repetitive Maintenance Preventable Functional Failures). |
| Site: | Clinton  |
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| Report | IR 05000461/2013005 Section 1R12 |
| Date counted | Dec 31, 2013 (2013Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.12 |
| Inspectors (proximate) | A Boland D Jones D Lords J Laughlin R Walton S Bell S Mischke W Schaupc Lipac Moore D Lords D Reeser E Sanchez Santiago K Carrington S Bell S Mischke W Schaup |
| INPO aspect | |
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Finding - Clinton - IR 05000461/2013005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Clinton) @ 2013Q4
Self-Identified List (Clinton)
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