05000220/FIN-2011008-01
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Finding | |
|---|---|
| Title | Inconsistencies Between Non-Safety Related Breaker Preventive Maintenance Templates and Station Practices |
| Description | In 2006, NMPNS began to apply Electric Power Research Institute (EPRI) recommended PM templates to NSR MCCBs. During the application process, NMPNS classified NSR MCCBS as Critical, Significant, Economic, or Run-to-Failure, and determined the PM activities to be performed. NMPNS appropriately classified breakers and assigned PM tasks using the site procedures and industry guidance available at that time. In 2007, two new procedures, CNG-AM-1.01-1018 Preventive Maintenance Program, and CNG-AM-1.01-2000 Scoping and Identification of Critical Components, were issued. CNG-AM-1.01-2000 requires a component to be classified as Critical if a functional failure would result in one of the following undesirable plant consequences: reactor scram/trip from any power level; loss of generation (shutdown, down power/derate >20%, or delay a unit Mode Change in startup); unplanned technical specification entry that requires shutdown with an action constraint of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or less; engineered safety feature (ESF) actuation, half-scram or half-ESF actuation that cannot be immediately reset; failure to control a critical function (level, temperature, pressure) of any of the following: reactor, primary containment, secondary containment, or fuel pool, or loss of any Maintenance Rule High Risk function; degradation of primary or secondary containment; degradation of capability to achieve or maintain cold shutdown; or loss of Emergency Operating Procedure function. NMPNS reviewed components that had previously been classified as Critical to ensure that the classification and PM activities complied with the new procedures. In 2009, fleet engineering standard CNG-FES-039 Preventive Maintenance Template Development, Review, Analysis and Application, was issued. This standard states that PM Template deviations for Critical components should be rarely applied and should only be reserved for severe/hardship situations, for non-conservative deviations. The inspectors identified several differences between the templates and actual PMs completed for NSR breakers, including scope and frequency of clean and inspect of Critical breakers, and thermography of breakers. In 2008, NMPNS missed an opportunity to re-evaluate if the clean and inspect PM task should be performed on NSR MCCBs based on operating experience. In 2008, NRC Information Notice (IN) 08-18 Loss of a Safety-Related Motor Control Center Caused by a Bus Fault, identified high resistance stab connections as the primary cause of a fire. The IN identified poor PM as one of the causes of the high resistance connection. Upon receiving IN08-18, NMPNS reviewed the PM templates for safety-related MCCBs, but not NSR MCCBs. In June 2011, NMPNS experienced a fire on a Significant NSR breaker, resulting in the declaration of an Unusual Event. The differences between the PM templates and actual station practices is unresolved pending inspector determination if a performance deficiency exists and if this issue is more than minor. |
| Site: | Nine Mile Point  |
|---|---|
| Report | IR 05000220/2011008 Section 4OA2 |
| Date counted | Dec 31, 2011 (2011Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | D Dempsey G Dentel N Lafferty T Ziev K Cronkk Kolaczykt Fish G Dentel J Brand N Perry E Keighley T Ziev B Fuller D Dempsey |
| INPO aspect | |
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Finding - Nine Mile Point - IR 05000220/2011008 | |||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Nine Mile Point) @ 2011Q4
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