ENS 44363
ENS Event | |
|---|---|
19:02 Jul 24, 2008 | |
| Title | Tech Spec Required Shutdown Due To Loss Of Essential Raw Cooling Water Pump With 2 Edg'S Oos |
| Event Description | WBN Unit 1 experienced a failure of the B-A ERCW pump on July 21, 2008, at 2:46 p.m. EDT. The plant entered LCD 3.7.8, Condition A, for one ERCW train inoperable and LCD 3.8.1, Condition C, with two required DGs in Train A inoperable concurrently. Required Actions for LCO 3.7.8 and LCD 3.8.1 required restoration of the inoperable ERCW train and one DG to OPERABLE status in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, respectively. Plant shutdown was initiated in accordance with LCD 3.7.8, Condition B and LCD 3.8.1, Condition G when the above Required Actions were not met. The root cause of the pump failure is unknown at this time. An event team has been set-up to determine cause of pump failure. Currently, the unit is performing a control shutdown, and all systems are functioning as expected.
The licensee does not expect the ERCW pump to be returned to service and will downpower at 15% per hour. The licensee expects to be in Mode 3 by 2030 EDT. All required safety systems for safe shutdown are operable. The licensee has notified the NRC Resident Inspector.
The TS required shutdown has been terminated on 7/24/08 at 1910 EDT, based on the receipt of an Emergency TS change. The plant exited LCO 3.8.1, Condition C and LCO 3.7.8, Condition A, and entered new LCO 3.7.8, Condition C. The revised TS will allow continued operation for an additional 7 days based, in part, on the implementation of an NRC approved Temporary Alternation. It is expected that the failed ERCW pump will be repaired within the new 10 day allowed outage time as specified in the Emergency TS change for LCO 3.7.8, Condition C (3 days were already used due to the inoperability of the B-A ERCW Pump occurred on 7/21, this leaves approximately 7 days left in the new action time.) The licensee notified the NRC Resident Inspector. Notified R2DO(Lesser). |
| Where | |
|---|---|
Watts Bar  Tennessee (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | |
| Time - Person (Reporting Time:+-3.98 h-0.166 days <br />-0.0237 weeks <br />-0.00545 months <br />) | |
| Opened: | Doug Holt 15:03 Jul 24, 2008 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Jul 24, 2008 |
| 44363 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (98 %) |
WEEKMONTHYEARENS 446322008-11-06T03:54:0006 November 2008 03:54:00
[Table view]10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Both Trains of Control Room Emergency Air Temperature Control Declared Inop ENS 443632008-07-24T19:02:00024 July 2008 19:02:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Tech Spec Required Shutdown Due to Loss of Essential Raw Cooling Water Pump with 2 Edg'S Oos 2008-07-24T19:02:00 | |