05000254/FIN-2014008-02
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Finding | |
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| Title | Non-Conservative DGCW Pump Break Horsepower Assumed in EDG Loading Analysis |
| Description | The inspectors identified an unresolved item (URI) regarding the motor load measured by the licensee for the Unit 1 DGCW pump that was determined to be less than the vendor certified pump performance data and pump load break horsepower (BHP) requirement at maximum flow conditions. Field measured pump motor load data was evaluated by the licensee and utilized as a design input in the Electrical Transient Analysis Program (ETAP) analysis for the emergency bus loading on offsite power and for the bus loading when powered by the EDG. The licensee did not fully evaluate and reconcile the effects on electrical bus and EDG loading analyses for the required pump BHP for the expected pump flow conditions, when the Unit 1 DGCW pump impeller was replaced in 2011 under work order (WO) 01301062 and evaluated under engineering change (EC) 369825. This condition was entered into the corrective action program as AR2420101 and AR2420905. The inspectors noted the licensee did not use vendor certified pump performance data when they evaluated the effects of the pump impeller replacement on the motor load. Instead, the licensee used field measured electrical load data as a design input to the ETAP electrical calculations for bus load flow and EDG loading, which the inspectors determined resulted in the bus and EDG loading being non-conservative. Technical Specification surveillance requirement (SR) 3.8.1.15 required loading the EDG between 2340 and 2600 kW for 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> and between 2730 and 2860 kW for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The inspectors determined for the 1/2 EDG (which the licensee identified had the worst 12 case loading), the margin between the actual EDG accident loading and the 2-hour minimum surveillance limit of 2730 kW was further reduced as a result of the increase in required pump brake horsepower from 90 to 101 BHP based on vendor certified pump performance data. The licensee concluded the pump brake horsepower increased only 5 HP, from 90 to 95 BHP, based on their field measurements of voltage and line current, but failed to reconcile the 5 HP load increase with vendor certified pump performance curve, which required approximately 101 BHP, or an 11 HP increase, at the established flow condition (1650 gpm). The licensee determined the additional increase in pump horsepower, when considering the vendor certified BHP for the pump at maximum flow conditions, remained within the minimum 2-hr load capability requirement established for TS SR 3.8.1.15. The inspectors determined the vendors pump load requirement derived from the certified pump performance curve of 101 BHP was approximately 6 HP more than the load determined by the licensee by field measurement of motor current and voltage. Field measurement of motor current and voltage was a licensee approved method in standard NES-EIC-11.01, Use of Analytical Software for AC Auxiliary Power System Analysis, to determine pump horsepower load for input to the ETAP analysis. The inspectors were concerned that if other load inputs to ETAP, derived from the measurement of voltage and current conditions, were also found to be less than actual maximum design basis load conditions, the EDG load could be adversely impacted. Resolution of this issue will be based on a licensee evaluation for the extent of condition for any additional impact on the subject bus loading conditions. Pending resolution, this item will be tracked as an unresolved item. |
| Site: | Quad Cities  |
|---|---|
| Report | IR 05000254/2014008 Section 1R21 |
| Date counted | Dec 31, 2014 (2014Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.21 |
| Inspectors (proximate) | A Dunlop A Stone B Jose C Baron G O'Dwyer M Jeffers R Walton S Kobylarzb Josec Mathews C Phillips J Cassidy J Wojewoda K Carrington K Stoedter M Garza R Murray |
| INPO aspect | |
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Finding - Quad Cities - IR 05000254/2014008 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Quad Cities) @ 2014Q4
Self-Identified List (Quad Cities)
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