05000341/FIN-2007005-04
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Finding | |
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| Title | |
| Description | The inspectors identified an unresolved item (URI) concerning incorrect temperature control valve elements installed on the 21 and 22 EDG jacket water and lube oil systems. The original EDG design required 170F temperature control elements in the jacket water system three-way temperature control valve and 180F temperature control elements in the lube oil system three-way temperature control valve to maintain EDG jacket water and lube-oil systems within the required temperature bands. The respective three-way valves control the inlet temperatures to the jacket water cooler and the lube oil cooler by sending or bypassing jacket water or lube oil to each systems cooler. The EDG jacket water and lube oil coolers are cooled by the service water system. In 1989, the EDG design was modified by DER-1691, Engineering Evaluation of Increasing Overloading Capacity on the Emergency Diesel Generators, which specified, in part, that 180F temperature control elements be installed in the jacket water system and 195F temperature control elements be installed in the lube oil system to account for an EDG power up-rate and a 10F increase in design basis ultimate heat sink temperature. The 180F and the 195F control elements assured EDG operability during a 30 minute period at a rating of 2300 kilowatt (kw) and a higher design basis service water temperature of 95F. The original 170F and 180F control elements were designed for a maximum short-term loading of 1950kw and a maximum service water temperature of 85F. Following completion of the EDG upgrades, on October 26, 2002, the original 170F jacket water control elements and 180F lube oil control elements were incorrectly installed on the 22 EDG under WO 02-33401. The incorrect jacket water and lube oil control elements were also installed on the 21 EDG on February 27, 2003, under WO 01-22824. Based on the available information, the inspectors were unable to verify the impact on EDG performance with the incorrect control elements installed due to a number of other upgrades that were also made to the EDGs under DER-1691. Some of these included upgraded heat exchangers on the jacket water and lube oil systems, an upgraded exhaust manifold, and upgrades to the EDG ventilation system. Entergy has contracted with a vendor to perform an analysis to determine the actual impact on past operability of having the original 170F control elements in the jacket water system and the 180F control elements in the lube-oil system based on actual service water temperatures that have been observed. The EDGs are currently operable because service water temperatures are substantially below the original service water design temperature of 75F. In addition, Entergy initiated actions to install the correct control elements in the two affected EDGs prior to service water temperatures exceeding 75F in 2008. The impact of incorrect jacket water and lube-oil control elements on the 21 and 22 EDGs will be an unresolved item pending NRC review of Entergys analysis of past operability. (URI 05000247/2007005-04, Impact of Incorrect Jacket Water and Lube Oil Control Elements on EDG Performance) |
| Site: | Fermi  |
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| Report | IR 05000341/2007005 Section 1R15 |
| Date counted | Sep 30, 2007 (2007Q3) |
| Type: | URI: |
| cornerstone | No Cornerstone |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | J Cassidy T Steadham D Reeser J Rutkowski M Bielby M Franke R Morris R Telsont Steadhamm Phalen R Morris A Wilson R Lerch D Mcneil |
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Finding - Fermi - IR 05000341/2007005 | |||||||||||||||||||||||||
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Finding List (Fermi) @ 2007Q3
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