05000341/FIN-2010005-02
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Finding | |
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| Title | Standby Liquid Control Test Tank Operability |
| Description | The inspectors identified an unresolved item (URI) for past operability of the standby liquid control (SLC) system and for the adequacy of the procedures utilized to perform the periodic SLC pump test. Specifically, the inspectors identified that the demineralized water in the SLC test tank had not been drained following each periodic test of the SLC pumps as a legacy condition. Further, they noted the SLC test tank could affect the SLC system operability following a seismic event, if there was still demineralized water remaining in the test tank. The SLC system is designed to provide the capability of bringing the reactor to a subcritical condition with the reactor in the most reactive, xenon free state without taking credit for control rod movement. The SLC system is classified as a seismic category I system. The SLC testing subsystem, which is designed to periodically test the two SLC pumps, includes the SLC test tank, some valves and piping. The SLC test tank is described in the USFAR as seismic category II/I. Therefore, it is a non-safety-related component within a safety-related envelope; and while not required to maintain its operability, it must not impact the category I portions of the system. To test the SLC pumps, demineralized water is put into the test tank, the SLC tank remains isolated, and the SLC pumps are lined up and locally started to recirculate the demineralized water through the SLC testing subsystem. The inspectors questioned whether the demineralized water in the SLC test tank was drained following the periodic test. Further, they questioned whether the SLC test tank could affect the SLC system operability following a seismic event, if there was still demineralized water remaining in the test tank. The plant procedure (24.139.02) used to periodically test the SLC pumps, as required by TS 3.1.7, did not require draining of the SLC test tank following testing. The procedure did not incorporate the General Electric maintenance instruction guidance to drain the test tank following pump testing. As an interim measure, the SLC test tank was drained of demineralized water, and the SLC pump testing procedure was revised to include guidance to drain the SLC test tank following testing. The initial operability evaluation provided by engineering concluded that the mounting of the SLC test tank would remain in place, and it would not impact the adjacent safety-related equipment. However, there are several outstanding technical questions regarding the evaluation. Engineering will revise the evaluation of past operability. Then the inspectors will review the revised operability evaluation to determine final resolution of this issue. Because the licensee is performing an engineering analysis of the SLC test tank mounting, this issue will be carried as an unresolved item in this report (URI 05000341/2010005-02, Standby Liquid Control Test Tank Operability). |
| Site: | Fermi  |
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| Report | IR 05000341/2010005 Section 1R15 |
| Date counted | Dec 31, 2010 (2010Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | R Jickling B Jose M Mitchell M Bielby J Neurauter D Jones R Morris D Kimble V Meghani R Jones J Bozgav Meghanij Tapp R Jones J Bozga R Temps M Learn J O'Donnell R Jickling M Mitchell J Neurauter R Morris |
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Finding - Fermi - IR 05000341/2010005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Fermi) @ 2010Q4
Self-Identified List (Fermi)
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