05000387/FIN-2010004-02
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Finding | |
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| Title | HPCI and RCIC CST Low-Level Suction Transfer Made Inoperable Due to Transfer of Water from Condenser Area to CST Berm |
| Description | The inspectors identified a Green NCV of Susquehanna Unit 1, TS 5.4.1, Procedures, for an inadequate procedure to transfer water from the condenser area to the condensate storage tank (CST) berm. Specifically, the procedure failed to include a maximum level in the CST berm that was acceptable to limit interactions with other safety-related equipment. The NCV was identified following the July 16, 2010, Unit 1 manual reactor scram due to a non-isolable circulating water leak in the main condenser area. Operations personnel commenced dewatering efforts by transferring water from the condenser area to the CST berm using a Liquid Radwaste Collection operating procedure as a guide. Water was transferred to the berm to a level sufficient to cause water intrusion into cable conduit and junction boxes containing High Pressure Coolant Injection system (HPCI) and Reactor Coolant Isolation Cooling system (RCIC) CST low level suction instrumentation which transfers HPCI and RCIC pump suction from the CST to the suppression pool. As a result, the low-level suction instrumentation became submerged affecting the reliability and capability of the HPCI and RCIC CST to suppression pool transfer function despite being required in Mode 3. The issue was entered into PPL\'s CAP (1297039). This performance deficiency is more than minor as it affected the equipment performance and procedural quality attributes of the corresponding Mitigating Systems cornerstone objective to ensure the reliability and capability of systems that respond to initiating events to prevent undesirable consequences (Le., core damage). Specifically, the low-level suction instrumentation was not designed for submergence. Transferring too much water from the condenser bay to the CST berm submerged the low-level suction instrumentation and affected the reliability and capability of the HPCI and RCIC CST to suppression pool transfer function. The finding was evaluated for significance using IMC 0609, Attachment 4, Phase 1 - Initial Screening and Characterization of Findings. Since the finding did not result in a loss of safety function or the loss of a train for greater than its TS allowed outage time, and was not potentially risk significant due to external event initiators, the finding was determined to be of very low safety significance (Green). This finding was determined to have a cross-cutting aspect in the area of Human Performance, Resources, because PPL did not ensure that procedures were adequate to assure nuclear safety. Specifically, operating procedure OP-169-004, Revision 17, did not specify a maximum level that could be transferred to the CST berm to limit interactions with safety-related, HPCI and RCIC low-level suction transfer instrumentation. |
| Site: | Susquehanna  |
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| Report | IR 05000387/2010004 Section 1R15 |
| Date counted | Sep 30, 2010 (2010Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | A Rosebrook D Molteni J Furia J Greives P Finney P Krohn R Mckinley |
| CCA | H.7, Documentation |
| INPO aspect | WP.3 |
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Finding - Susquehanna - IR 05000387/2010004 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Susquehanna) @ 2010Q3
Self-Identified List (Susquehanna)
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