05000382/FIN-2009009-01
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Finding | |
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| Title | Failure to Account for Reduction of Flow from the Emergency Feedwater System to the Steam Generators |
| Description | The team identified a noncited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control. Specifically, the licensee did not account for reduction of flow from the emergency feedwater system when analyzing the flow rate to the steam generators and establishing the acceptance criteria for the performance of the motor-driven emergency feedwater pumps. The factors associated with the loss of flow included the emergency diesel generator under frequency of 0.3 Hertz allowed by technical specifications, and not accounting for accepted reverse flow (back leakage) of 25 gpm through the turbine-driven discharge check valve. The pumps had a documented analyzed margin of 55 gpm. The margin was reduced by 24 gpm due to allowed diesel under-frequency. Another reduction was attributed to the accepted reverse flow (back leakage) of 25 gpm through the turbine-driven discharge check valve. This left the combined margin of both emergency feedwater motor-driven pumps at 6 gpm. The licensee entered this issue into the corrective action program as Condition Reports CR-WF3-2009-04731, CR-WF3-2009-04528, and CR-WF3-2009-05043, and performed an operability assessment for each of these factors. This finding is more than minor because it affected the mitigating systems cornerstone attribute of design control to ensure the availability, reliability, and capability of safety systems that respond to initiating events to prevent undesirable consequences. This finding closely parallels Inspection Manual Chapter 0612, Appendix E, Example 3.j, Not Minor: If the engineering calculation error results in a condition where there is now a reasonable doubt on the operability of a system or component, or if significant programmatic deficiencies were identified with the issue that could lead to worse errors if uncorrected. This finding is of very low safety significance (Green) because it was not a design issue resulting in loss of function, did not represent an actual loss of a system safety function, did not result in exceeding the Technical Specification allowed outage time, and did not affect external event mitigation. Some margin in total flow still remained to compensate for the reduced pump performance if operated at the reduced-frequency. The inspectors determined that the finding has a cross cutting aspect in the area of Problem Identification and Resolution, associated with Operating Experience. The licensee had received NRC Information Notice 2008-02, which specifically identified the diesel under-frequency as a potential problem for ac motor-operated pumps, and test acceptance criteria concerns which would have ensured the capability of the equipment to perform its function under the most limiting conditions. The licensee failed to identify the applicability of these potential problems to the emergency feedwater motor-operated pumps and take proper actions P.2(a). |
| Site: | Waterford  |
|---|---|
| Report | IR 05000382/2009009 Section 1R21 |
| Date counted | Sep 30, 2009 (2009Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.21 |
| Inspectors (proximate) | K Clayton R Kopriva J Adams M Runyan J Chiloyan M Yeminy R Kellar B Correll |
| CCA | P.5, Operating Experience |
| INPO aspect | CL.1 |
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Finding - Waterford - IR 05000382/2009009 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Waterford) @ 2009Q3
Self-Identified List (Waterford)
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