05000261/FIN-2010009-13
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Finding | |
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Title | Dedicated Shutdown Diesel Generator Failed to Start Due to Low Starting Air Pressure |
Description | The team reviewed the circumstances which resulted in a failure of the DSDG to start. The team reviewed completed procedures, log entries, system drawings and performed a system walkdown. At 18:52 on March 28, the DS bus was automatically de-energized, as designed, due to undervoltage on 4 kV Bus 3. As a result, the DSDG support equipment, such as the starting air system compressor and battery charger, lost power. Based in part on adequate starting air pressure, the licensee considered the DSDG available for the purpose of assessing on-line risk. The log reading normal minimum value for starting air pressure is 165 psig and operators were monitoring this parameter twice per day. At 14:41 on March 31 the licensee attempted to start the DSDG and re-energize the DS bus to maintain adequate DSDG support parameters such as starting air pressure and battery voltage. Starting air pressure had decreased to 100 psig and the DSDG did not start. The licensee successfully started the DSDG on April 1 at 13:40 by pressurizing the DSDG starting air receiver tank using high pressure air bottles. Both the E-1 and E-2 safety buses were energized during this time with Bus E-1 powered from off-site power and Bus E-2 supplied from EDG B. The licensee entered Condition Reports 390954 and 390958 into their corrective action program. Additional review by the NRC will be required to determine if the DSDG was available when credited in the licensees risk assessment during the plant cooldown to Mode 4. This review will also determine whether this issue represents a performance deficiency. An Unresolved Item will be opened pending completion of this review. The issue will be identified as URI 05000261/2010009-13, Dedicated Shutdown Diesel Generator Failed to Start Due to Low Starting Air Pressure. |
Site: | Robinson |
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Report | IR 05000261/2010009 Section 4OA5 |
Date counted | Jun 30, 2010 (2010Q2) |
Type: | URI: |
cornerstone | Mitigating Systems |
Identified by: | NRC identified |
Inspection Procedure: | IP 93800 |
Inspectors (proximate) | J Hanna J Hickey L Miller L Wert P Fillion P Pieringer R Monk S Currie F Ehrhardta Nielsenc Kontz D Bollock D Mills G Laska G Skinner J Beavers J Brady J Hickey J Worosilo M Bates P Braxton R Musserr Monkf Ehrhardt J Hanna L Miller J Hickey P Fillion L Wert P Pieringer S Currie |
INPO aspect | |
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Finding - Robinson - IR 05000261/2010009 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Robinson) @ 2010Q2
Self-Identified List (Robinson)
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