ENS 51228
ENS Event | |
|---|---|
06:39 Jul 14, 2015 | |
| Title | Secondary Containment Pressure Increase Above Technical Specification Limit |
| Event Description | Reactor Building (Secondary Containment) pressure increased to above the Technical Specification Surveillance requirement of 0.25 inches vacuum water gauge for approximately 2 minutes during a planned surveillance test due to a subsequent failure of REA-FN-1A [Exhaust Fan] to manually start during restoration from the surveillance test. This event is reportable as an event that could have prevented fulfillment of a safety function needed to control the release of radiation and mitigate the consequences of an accident.
Prior to taking test data the surveillance test directs declaring Secondary Containment inoperable in anticipation of potentially exceeding 0.25 inches vacuum water gauge reactor building pressure during the conduct of the surveillance. Consequently Technical Specification LCO 3.6.4.1.A was entered with a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> completion time to restore Secondary Containment to an operable state. Upon failure of REA-FN-1A to start immediate actions were taken to close reactor building ventilation dampers and secure ROA-FN-1A [Supply Fan]. Following closure of ventilation dampers and stopping ROA-FN-1A reactor building pressure was quickly restored to less than 0.25 inches vacuum water gauge with Standby Gas Treatment that was already in operation as part of the surveillance test. There were no radiological releases associated with the event. No safety system actuations or isolations occurred. The licensee notified the NRC Resident Inspector. Maximum Secondary Containment pressure noted was 0.1 inches positive water gage.
Subsequent to the initial report, Columbia has since determined that per NUREG-1022 3.2.7 the event was not reportable as Secondary Containment was 'declared inoperable as a part of a planned evolution ... in accordance with an approved procedure and [Columbia's] TS [Technical Specifications].' No condition has been discovered that would have resulted in the system being declared inoperable prior to the surveillance. Therefore, this event is not considered to be a condition that could have prevented fulfillment of a safety function or a condition prohibited by TS and is not reportable to the NRC as a Licensee Event Report (LEA) per 10 CFR 50.73. The NRC Senior Resident Inspector will be notified. Notified the R4DO (Campbell). |
| Where | |
|---|---|
Columbia Generating Station  Washington (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-1.03 h-0.0429 days <br />-0.00613 weeks <br />-0.00141 months <br />) | |
| Opened: | Zackary Dunham 05:37 Jul 14, 2015 |
| NRC Officer: | John Shoemaker |
| Last Updated: | Aug 25, 2015 |
| 51228 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (64 %) |
| After | Power Operation (64 %) |