05000440/FIN-2007010-04
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Finding | |
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| Title | Quality of Immediate Investigations |
| Description | The Team reviewed two Immediate Investigation reports addressing the MFPs operation without minimum flow for 6 minutes and an operators observation that the scram valves for two control rods indicated that they were not fully open. The Team identified that neither investigation adequately supported their respective conclusions. The Immediate Investigation associated with CR 07-30700, Motor Feed Pump Ran with No Minimum Flow, concluded that there had been no damage to the pump. The support for that conclusion stated that the event was similar to a previous event and because the pump had sustained no damage during the previous event, that no damage would have been sustained during the November 28, 2007, event. The assertion that the two events were similar was not supported by any documentation. Additional reviews provided sufficient information to support the initial conclusion that no immediate damage had been sustained by the pump. The Immediate Investigation associated with CR 07-30689, 2 Control Rods Did Not Have Both of Their Scram Valves Open, concluded that because the control rod drive inserted the scram valves must have opened. This causal analysis ignored the design feature of the control rod drive mechanism that only required the scram vent valve to open for the control rod to full insert, utilizing reactor pressure with no reliance on the hydraulic unit water accumulator. Additional review by the licensee provided sufficient information, in the form of comparative scram times with control rods at like positions, to support the conclusion that the scram inlet valves had opened. The quality of the licensees Immediate Investigations is considered an URI (05000440/2007010-004) pending NRC review of CRs 07-30853 and 30854 documenting the inadequate investigations and will be followed up during a subsequent inspection. |
| Site: | Perry  |
|---|---|
| Report | IR 05000440/2007010 Section 4OA3 |
| Date counted | Dec 31, 2007 (2007Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | M Wilk A Dahbur G Wright M Franke J Cameronm Wilks Sheldon C Brown G Wright |
| INPO aspect | |
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Finding - Perry - IR 05000440/2007010 | |||||||||||||||||||||||||||||||||
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Finding List (Perry) @ 2007Q4
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