ENS 43436
ENS Event | |
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07:15 Jun 21, 2007 | |
Title | Hpci Inoperable Due To Quarterly Valve Stroke Test Failure |
Event Description | During performance of the quarterly HPCI valve stroke test the HV-55-2F006, HPCI pump discharge isolation valve to Core Spray failed to open within the maximum allowed time. The HV-55-2F006 valve is a motor operated valve and the maximum allowed opening time is 17.25 seconds. The valve was given an open signal via the hand switch as required by the test but did not initially respond. Several minutes later the valve went full open. HPCI was declared inoperable at 0315 on 6/21/2007. Cause for valve stroke time failure is not known at this time.
As a result, the licensee is in a 14 day shutdown LCO. The licensee notified the NRC Resident Inspector.
This is a retraction of the event notification made on 6/21/07 at 04:05 hours EDT. This event (#43436) was initially reported as a condition that at the time of discovery could have prevented the fulfillment of the High Pressure Coolant Injection (HPCI) system safety function under the requirement of 10CFR50.72(b)(3)(v)(D). The Unit 2 HPCI system was declared inoperable due to failure of the HPCI pump discharge isolation valve to Core Spray to open within the maximum allowed time during surveillance testing. The valve was required to open within 17.25 seconds but opened several minutes after the open signal was initiated. The open contactor was replaced and the valve was successfully tested. The affected valve was declared operable on 6/22/07 at 04:07 hours. The HPCI system was restored to operable on 6/23/07 at 04:07 hours following completion of maintenance and testing activities. An evaluation determined that HPCI was capable of injecting sufficient flow to complete its safety function through the unaffected operable injection flow path to the feedwater header. The achievable flow rate would have exceeded the leakage from a one-inch liquid line break. Also, HPCI operation remained capable of being terminated by operator action during an ATWS event. Therefore, HPCI remained capable of fulfilling its safety function while the injection flow path to Core Spray was unavailable. A condition did not exist at the time of discovery that could have prevented the fulfillment of the HPCI safety function. The licensee notified the NRC Resident Inspector. R1DO (White) notified. |
Where | |
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Limerick Pennsylvania (NRC Region 1) | |
Reporting | |
10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
Time - Person (Reporting Time:+-3.17 h-0.132 days <br />-0.0189 weeks <br />-0.00434 months <br />) | |
Opened: | Ned Dennin 04:05 Jun 21, 2007 |
NRC Officer: | Joe O'Hara |
Last Updated: | Aug 1, 2007 |
43436 - NRC Website
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Unit 2 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |
Limerick with 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
WEEKMONTHYEARENS 561632022-10-14T14:07:00014 October 2022 14:07:00
[Table view]10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection Inoperable ENS 554842021-09-23T18:43:00023 September 2021 18:43:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection System Declared Inoperable ENS 550002020-11-16T10:15:00016 November 2020 10:15:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection Inoperable ENS 533412018-04-17T14:30:00017 April 2018 14:30:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection System Declared Inoperable ENS 531082017-12-08T18:10:0008 December 2017 18:10:00 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 a Leaking Check Valve ENS 528742017-07-27T17:15:00027 July 2017 17:15:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Core Injection System Declared Inoperable ENS 513682015-09-03T23:01:0003 September 2015 23:01:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) Declared Inoperable ENS 492392013-08-05T18:56:0005 August 2013 18:56:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Both Offsite Power Sources Inoperable During Undervoltage Testing ENS 488372013-03-20T18:47:00020 March 2013 18:47:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) Turbine Oil Leak ENS 469792011-06-23T15:00:00023 June 2011 15:00:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection System Declared Inoperable ENS 464742010-12-12T16:28:00012 December 2010 16:28:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection System Unavailable ENS 446232008-11-02T20:50:0002 November 2008 20:50:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci System Declared Inoperable Due to Controller Failure ENS 436452007-09-17T05:49:00017 September 2007 05:49:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Unable to Perform It'S Safety Related Function ENS 434362007-06-21T07:15:00021 June 2007 07:15:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Inoperable Due to Quarterly Valve Stroke Test Failure ENS 429072006-10-15T12:46:00015 October 2006 12:46:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Inoperable ENS 428832006-10-07T10:57:0007 October 2006 10:57:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Declared Inoperable ENS 415402005-03-28T22:38:00028 March 2005 22:38:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection Temporarily Inoperable ENS 406002004-03-19T19:08:00019 March 2004 19:08:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci System Declared Inoperable at Limerick 1 Due to a Broken Hand Switch 2022-10-14T14:07:00 | |