ENS 46628
ENS Event | |
|---|---|
05:00 Feb 20, 2011 | |
| Title | Technical Specification Required Shutdown-Reactor Building Closed Cooling Water Train Inoperable |
| Event Description | At 0000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> on Sunday, February 20, 2011, the Pilgrim Nuclear Power Station (PNPS) commenced a controlled shutdown of the reactor due to the 'B' train of Reactor Building Closed Cooling Water (RBCCW) being declared inoperable at 1250 hours0.0145 days <br />0.347 hours <br />0.00207 weeks <br />4.75625e-4 months <br /> on February 18, 2011 and expected to exceed its 72-hour Limiting Condition for Operability (LCO) as required by TS prior to return to operable status.
With the plant operating at 100% power, leakage of Salt Service Water (SSW) was detected in the RBCCW system due to high chloride levels and increased inventory in the system. An investigation into the event determined that the source of the SSW was isolated to the 'B' RBCCW heat exchanger which is designed to cool RBCCW under normal and post-accident conditions. The quantity of the leakage was determined to exceed the design limits established to ensure post-accident operation of the system and the 'B' train of RBCCW was subsequently declared inoperable. The leak identification and repair activities are expected to exceed the TS LCO for the RBCCW system and therefore a controlled shutdown of the reactor was initiated. This event had no impact on the health and/or safety of the public. The licensee has notified the NRC Senior Resident Inspector. This 4-hour notification is being made in accordance with 10 CFR 50.72 (b)(2)(i). |
| Where | |
|---|---|
| Pilgrim Massachusetts (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | |
| Time - Person (Reporting Time:+-4.08 h-0.17 days <br />-0.0243 weeks <br />-0.00559 months <br />) | |
| Opened: | Dave Noyes 00:55 Feb 20, 2011 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Feb 20, 2011 |
| 46628 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (60 %) |
Pilgrim with 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | |
WEEKMONTHYEARENS 486852013-01-21T01:50:00021 January 2013 01:50:00
[Table view]10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification (Ts) Required Shutdown - Safety Relief Valve Declared Inoperable ENS 475532011-12-26T17:50:00026 December 2011 17:50:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown - Safety Relief Valve Declared Inoperable ENS 474542011-11-17T20:15:00017 November 2011 20:15:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown Due to Inoperable Feedwater Check Valve ENS 468522011-05-14T06:45:00014 May 2011 06:45:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown Due to Inability to Maintain Specified Differential Pressure Between Drywell and Suppression Chamber ENS 466282011-02-20T05:00:00020 February 2011 05:00:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown-Reactor Building Closed Cooling Water Train Inoperable 2013-01-21T01:50:00 | |