ENS 43711
ENS Event | |
|---|---|
02:45 Oct 11, 2007 | |
| Title | Unit 2 Hpci Pump Seal Failure |
| Event Description | On 10/10/2007 a 2245, the Unit 2 High Pressure Coolant Injection (HPCI) Pump developed a leak of approximately 5 gpm due to a suspected pump seal failure.
HPCI was in service for a scheduled surveillance test per plant procedure OPT-09.2, HPCI System Operability Test. When the leak was identified, operators secured HPCI. The leak was isolated by securing the pump, closing the pump suction isolation valves, isolating the keep fill supply valves. Operators declared the Unit 2 HPCI System inoperable when the keep fill system was isolated. No automatic system isolation or actuation set points were reached. Safety significance is minimal due to the operability and availability of redundant systems. If a Loss of Coolant Accident (LOCA) were to occur the Reactor Core Isolation Cooling (RCIC) System would automatically inject and if necessary the Automatic Depressurization System (ADS) would depressurize the reactor pressure vessel allowing low pressure Emergency Core Cooling Systems (ECCS) to inject. All low pressure ECCS are operable. Plant risk has been evaluated and remains 'Green'. The Unit 2 HPCI system has been removed from service. The pump suction isolation valves have been closed. Injection piping keep fill connections have been isolated. These actions were taken to stop the leakage of system water out of the failed pump seal. Actions have been taken to protect redundant safety systems, including the RCIC System and ADS. In accordance with Technical Specification 3.5.1 Required Actions: RCIC has been verified to be operable, and HPCI must be restored to operable status within 14 days. HPCI pump seal replacement is being planned in accordance with the site's Work Management process. This event has been entered into the sites Corrective Action Program and an investigation into the cause of the seal failure will be performed. The licensee notified the NRC Resident Inspector.
On October 11, 2007, at 0520 hours0.00602 days <br />0.144 hours <br />8.597884e-4 weeks <br />1.9786e-4 months <br />, the control room Supervisor made a notification (Event Number 43711) to the NRC Operations Center in accordance with. 10 CFR 50.72(b)(3)(v)(D) (i.e., any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident). The notification was made as a result of the High Pressure Coolant Injection (HPCI) system being declared inoperable due to indications of a main pump seal leak. Specifically, water was discovered leaking an approximate five gallons per minute from the main pump turbine side seal during performance of OPT-09.2, 'HPCI System Operability Test.' Basis for Retraction Unit 2 HPCI was declared inoperable when the main pump seal leak was first identified. Upon further detailed engineering evaluation, it has been determined that the HPCI system was not rendered inoperable as a result of the condition identified on October 10, 2007, and was able to fulfill its safety functions in the degraded condition. The HPCI pump uses seal purge water piping in combination with mechanical seals to limit shaft leakage. The investigation found debris blocking the seal purge piping, which led to the seal faces overheating and subsequent failure. Water intrusion into the oil system was determined to be the limiting impact of the seal failure. The limiting event for HPCI was determined to be 4.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of operation during a loss of Feedwater event with HPCI only, due to the short runtimes followed by long idle times which maximize water intrusion. The evaluation concluded that the HPCI pump would be able to operate for 4.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, as required for the limiting event, and would be available for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. Thus, Unit 2 HPCI was degraded but able to meet all required safety functions. On this basis, the HPCI system was capable of performing its safety functions to mitigate the consequences of an accident and the issue is not reportable under 10 CFR 50.72(b)(3)(v)(D). The NRC Resident was notified of this retraction. Notified R2DO(Bonner) |
| Where | |
|---|---|
Brunswick  North Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| LER: | 05000324/LER-2007-004 |
| Time - Person (Reporting Time:+2.58 h0.108 days <br />0.0154 weeks <br />0.00353 months <br />) | |
| Opened: | Tom Hackler 05:20 Oct 11, 2007 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Jan 30, 2008 |
| 43711 - NRC Website | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Brunswick with 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
WEEKMONTHYEARENS 559972022-07-16T00:20:00016 July 2022 00:20:00
[Table view]10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (HPCI) Inoperable ENS 557802022-03-10T01:13:00010 March 2022 01:13:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (HPCI) Inoperable ENS 541162019-06-13T01:27:00013 June 2019 01:27:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) Inoperable ENS 531232017-12-17T08:16:00017 December 2017 08:16:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) System Declared Inoperable ENS 527882017-06-05T17:52:0005 June 2017 17:52:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Control Room Air Conditioning and Emergency Ventilation Systems Inoperable ENS 526792017-04-14T04:15:00014 April 2017 04:15:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Drywell and Suppression Chamber Simultaneously Aligned for Venting ENS 520642016-07-05T20:40:0005 July 2016 20:40:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) System Declared Inoperable ENS 517692016-03-04T17:35:0004 March 2016 17:35:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Emergency Diesel Generator Declared Inoperable ENS 508162015-02-12T18:36:00012 February 2015 18:36:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Declared Inoperable During Weekly Inspection ENS 485962012-12-14T18:06:00014 December 2012 18:06:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Control Building Emergency Ventilation System Inoperable for Two Minutes ENS 478932012-05-02T21:58:0002 May 2012 21:58:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection Inoperable Due to Erratic Governor Operation ENS 474932011-12-01T18:44:0001 December 2011 18:44:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Control Room Air Conditioning and Control Room Emergency Ventilation Systems Inoperable ENS 467632011-04-17T02:52:00017 April 2011 02:52:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Inoperable Due to Lube Oil Pressure Low Out of Band ENS 467402011-04-07T21:40:0007 April 2011 21:40:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Loss of the Control Room Emergency Ventilation System ENS 452642009-08-14T23:58:00014 August 2009 23:58:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Inoperable Due to Automatic Closure of Inboard Isolation Valve ENS 448102009-01-28T01:07:00028 January 2009 01:07:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Unit 2 Hpci System Inoperable for Two Hours Due to Condensate in Exhaust Line ENS 447932009-01-21T18:00:00021 January 2009 18:00:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Loss of Control Room Air Conditioning and Emergency Ventilation System ENS 447482009-01-01T19:30:0001 January 2009 19:30:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Two Emergency Diesel Generators Declared Inoperable Due to Component Failure ENS 443092008-06-19T21:35:00019 June 2008 21:35:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Control Room Ventilation Inoperable ENS 442622008-06-03T17:13:0003 June 2008 17:13:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Loss of Control Room Emergency Ventillation System for 12 Minutes ENS 441792008-04-30T03:13:00030 April 2008 03:13:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) System Inoperable Due to Seal Leak ENS 437112007-10-11T02:45:00011 October 2007 02:45:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Unit 2 Hpci Pump Seal Failure ENS 431972007-02-28T03:26:00028 February 2007 03:26:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) Inoperability ENS 429062006-10-13T17:57:00013 October 2006 17:57:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) System Declared Inoperable Due to Potential Turbine Exhaust Diaphragm Failure ENS 424882006-04-10T20:30:00010 April 2006 20:30:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Control Room Emergency Ventilation System Declared Inoperable Due to Design Deficiency ENS 423052006-02-03T04:36:0003 February 2006 04:36:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) System Inoperable Due to One Hpci Turbine Exhaust Vacuum Breaker Isolation Valve Failure ENS 422542006-01-12T14:20:00012 January 2006 14:20:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Control Room Air Conditioning and Control Room Emergency Ventilation Systems Inoperable ENS 418952005-08-05T22:40:0005 August 2005 22:40:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown Due to Inoperability of All Emergency Diesel Generators ENS 416922005-05-12T08:11:00012 May 2005 08:11:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.73(a)(1), Submit an LER Technical Specification Required Shutdown Due to Loss of Emergency Bus E1 ENS 408332004-06-22T13:00:00022 June 2004 13:00:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Presure Coolant Injection System Inoperable Due to Maintenance ENS 407142004-04-29T02:30:00029 April 2004 02:30:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci System Inoperable Following Planned Maintenance ENS 406362004-04-03T08:00:0003 April 2004 08:00:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection System Inoperable ENS 403182003-11-13T03:22:00013 November 2003 03:22:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection System Isolation During Testing 2022-07-16T00:20:00 | |