05000361/FIN-2008010-01
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Finding | |
|---|---|
| Title | Inadequate Design Control for Design Basis of Ccw/Cwc Heat Exchangers |
| Description | The team identified a noncited violation of 10 CFR 50, Appendix B, Criterion III, Design Control, for failure to ensure that plant conditions were consistent with design calculation inputs and assumptions (rate of established component cooling water heat exchanger tube plugging). Specifically, there were no procedures to verify that the periodic heat treatments of the intake tunnel and intake structure were effective and that the population of shells available for plugging the component cooling water heat exchangers was consistent with the historical data used to develop the engineering calculation and operating instruction curves. As a result, the design basis calculation and operating instructions did not ensure the capability of the heat exchangers to perform their design function during anomalous conditions. The licensee has entered this into their corrective action program as Notification NN 200006369. This finding is more than minor in that the performance of the component cooling water heat exchangers is essential in protecting the mitigating systems cornerstone objective (design control and equipment performance attributes) of ensuring the availability, reliability, and capability of systems needed to mitigate the consequences of an accident. Specifically, the existing design analyses did not adequately demonstrate that the component cooling water heat exchangers would perform adequately in the event of anomalous tube plugging events and plant procedures did not ensure that these anomalous events would be detected and mitigated prior to the heat exchangers being plugged. These deficiencies represented reasonable doubt regarding the operability of the component cooling water heat exchangers. Using the Inspection Manual Chapter 0609, Significance Determination Process, Phase 1 Worksheets, the finding is determined to have very low safety significance (Green) because the deficiency did not result in a loss of safety function of component cooling water Train A for greater than the Technical Specification allowed outage time. Train B was not adversely affected by this event. This finding was reviewed for cross-cutting aspects and none were identified since the performance deficiency is long standing and is not indicative of current licensee performanc |
| Site: | San Onofre  |
|---|---|
| Report | IR 05000361/2008010 Section 1R21 |
| Date counted | Sep 30, 2008 (2008Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.21 |
| Inspectors (proximate) | L Ellershaw J Adams C Baron G Skinner P Gage R Bywater M Bloodgood D Reinert |
| INPO aspect | |
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Finding - San Onofre - IR 05000361/2008010 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (San Onofre) @ 2008Q3
Self-Identified List (San Onofre)
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