Finding | |
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| Title | Failure to properly evaluate extended power uprate for its impact on post-scram reactor vessel water level to prevent water intrusion into the HPCI steam supply line |
| Description | An apparent violation (AV) of 10 CFR 50, Appendix B, Criterion III, Design Control, having a preliminary low to moderate safety significance (White) was identified as a result of the inspectors review of a January 30, 2004, scram event. Water intrusion into the high pressure coolant injection (HPCI) system turbine steam supply line occurred as a result of the scram and rendered the HPCI system inoperable. The inspectors determined that the licensee implemented extended power uprates on Unit 2 in 2001 and Unit 3 in 2002, but failed to verify the adequacy of design for the implementation of extended power uprate to respond to changes in post-scram reactor vessel water level to prevent water intrusion into the HPCI steam supply line. The finding was determined to be greater than minor because it impacted the mitigating systems cornerstone. The finding was preliminarily determined to be of low to moderate safety significance following the performance of a case-specific Phase 3 SDP evaluation. Corrective actions taken by the licensee included modifying the feedwater level control system post-scram level setpoints and dynamic modeling of the reactor vessel level response. |
| Site: | Dresden  |
|---|---|
| Report | IR 05000237/2005014 Section 4OA3 |
| Date counted | Mar 31, 2006 (2006Q1) |
| Type: | AV: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | D Passehl M Ring D Smith L Kozak |
| INPO aspect | |
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Finding - Dresden - IR 05000237/2005014 | |||||||||
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Finding List (Dresden) @ 2006Q1
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