ENS Event | |
|---|---|
21:00 Nov 19, 2015 | |
| Title | Unanalyzed Condition Due to Spent Fuel Pool Temperature Outside Limits |
| Event Description | A review of operations log data revealed the Unit 2 Spent Fuel Pool temperature was allowed to drift approximately two degrees below the accepted analyzed temperature of 68 degrees F. The Extent of Condition is under review and the number of instances has not been fully determined. It is possible Unit 3 may have also been affected.
As described in the San Onofre UFSAR, Section 9.1.2.3 'Design Basis for Fuel Storage and Handling,' one of the conditions assumed in meeting the design basis, is as follows: the most adverse delta-k (reactivity change) was analyzed for a pool temperature range from 68 degree F to 160 degree F. Although the temperature decrease is considered unlikely to have a significant impact on the results of the analysis, it is being reported under 10 CFR 50.72(b)(2) as an unanalyzed condition because there is at this time no analysis of record for the reduced temperature condition. There were and continue to be no observed, abnormal effects from the temperature drop below 68 degrees F, and no impact on the health or safety of plant personnel of the public. Re-analysis is in progress and is expected to demonstrate that the criticality acceptance criteria of 10CFR50.68 were met at all times. The licensee notified the Regional NRC Contact. |
| Where | |
|---|---|
San Onofre  California (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+-1.83 h-0.0763 days <br />-0.0109 weeks <br />-0.00251 months <br />) | |
| Opened: | James Vrla 19:10 Nov 19, 2015 |
| NRC Officer: | Vince Klco |
| Last Updated: | Nov 19, 2015 |
| 51554 - NRC Website
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WEEKMONTHYEARENS 515542015-11-19T21:00:00019 November 2015 21:00:00
[Table view]10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Spent Fuel Pool Temperature Outside Limits ENS 461822010-08-17T10:00:00017 August 2010 10:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Potential Wiring Discrepancy 2015-11-19T21:00:00 | |