ENS 42491
ENS Event | |
|---|---|
13:24 Apr 11, 2006 | |
| Title | Technical Specification Required Shutdown |
| Event Description | At 0924 Unit 2 experienced multiple Fire Protection System Deluge Valve actuations for the Main Filter Banks, System Station Service Transformers (SSSTs) 2A and 2B, the Main Transformer, Condensate Polishing building ventilation charcoal filter and Decontamination building ventilation charcoal filter. The Transformers were unaffected by the spray actuation and remained operable.
No actual fire occurred or was observed for these components or areas. The Motor driven and Engine Driven Fire Pumps automatically started upon the actuations. These above noted areas and components received water spray down until manually isolated. It was verified that both of the Charcoal Main Filter Banks (TS 3.7.8.1) had become wetted down by the spray actuation. With the charcoal main filter banks wet, their filtering capability becomes impacted and is being evaluated. These filter components were declared inoperable. At 0924, Unit 2 entered the actions of Tech. Spec. 3.0.3. The requirements of Tech Spec 3.0.3 are: Within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> action shall be initiated to place the unit in Hot Standby within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, Hot Shutdown within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and Cold Shutdown within the subsequent 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. At 1055 Unit 2 commenced shutdown at 20%/hr. The cause of the multiple actuations is not understood at this time. An Event Response Team has been formed to investigate the issue. All other safety related systems are operable. The action required for the licensee to exit this Tech Spec required shutdown will be to restore the charcoal filter banks to operable status. The licensee estimates the investigation, troubleshooting, and repair efforts to last approximately 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br />. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Beaver Valley  Pennsylvania (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | |
| Time - Person (Reporting Time:+-0.78 h-0.0325 days <br />-0.00464 weeks <br />-0.00107 months <br />) | |
| Opened: | Andrew Hewitt 12:37 Apr 11, 2006 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Apr 11, 2006 |
| 42491 - NRC Website | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (65 %) |