ENS 48481
ENS Event | |
|---|---|
05:06 Nov 6, 2012 | |
| Title | High Pressure Coolant Injection Actuation Signal |
| Event Description | On Tuesday, November 06, 2012, at 00:06 EST, during the application of a tag-out associated with feedwater level control, the 12 feedwater flow control valve (FCV-29-137) unexpectedly partially opened. As a result, reactor vessel water level rose to the high level turbine trip set point causing the main turbine to trip. The turbine trip signal then resulted in the initiation of High Pressure Coolant Injection (HPCI) channels 11 and 12 logic. No actual system component starts or actuations occurred as a result of the logic initiation and no actual HPCI injection occurred due to the system configuration, nor was injection required.
Actions were taken to manually isolate the 12 feedwater flow control valve and reactor vessel water level was restored to normal. This meets NRC 8-Hour reporting criteria per 10 CFR 50.72(b)(3)(iv)(A) due to a valid actuation of the High Pressure Coolant Injection System. The licensee has notified the NRC Resident Inspector.
This notification is being made to retract Event Notification (EN) #48481, which reported an automatic actuation of the High Pressure Coolant Injection (HPCI) system initiation logic. The HPCI system is automatically initiated based on conditions representing a small break loss of coolant accident (LOCA). The initiation signals are: - Low reactor water level - This is a direct indication of a potential loss of adequate core cooling. - Turbine trip - During a LOCA within the drywell, high drywell pressure due to the line break will cause a reactor scram, which causes a turbine trip, which then by design initiates the HPCI system. The event occurred with the reactor in the cold shutdown condition, with the main turbine and main turbine shaft-driven feedwater pump (#13) out of service. In the cold shutdown condition, the probability of a LOCA is low and the HPCI system is not required by the Technical Specifications to be operable. Neither of the conditions requiring actuation of the safety function of the HPCI system (high drywell pressure or low reactor water level) was present. Although the turbine trip signal was in response to an actual sensed high reactor water level condition, high reactor water level is not a plant condition satisfying the requirement for actuation of the safety function of the HPCI system. With reactor vessel water level high, the safety function of the HPCI system (i.e. to provide adequate core cooling) was already completed. Thus, the HPCI initiation signal was invalid, and the event is not reportable under 10 CFR 50.72(b)(3)(iv)(A). The NRC Resident Inspector has been informed. Notified the R1DO (Hunegs).
Upon further review, it has been determined the event did constitute a valid actuation of the HPCI system and is reportable per 10CFR50.72(b)(3)(4)(A). The licensee will notify the NRC Resident Inspector. Notified the R1DO (Joustra). |
| Where | |
|---|---|
Nine Mile Point  New York (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| LER: | 05000220/LER-2012-007 |
| Time - Person (Reporting Time:+-1.17 h-0.0488 days <br />-0.00696 weeks <br />-0.0016 months <br />) | |
| Opened: | Don Sheehan 03:56 Nov 6, 2012 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Apr 24, 2013 |
| 48481 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 570042024-03-04T00:42:0004 March 2024 00:42:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Due to Main Turbine Trip on LOW Condenser Vacuum ENS 567102023-09-02T10:32:0002 September 2023 10:32:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Automatic Reactor Scram Due to Feedwater Transient ENS 560892022-09-04T20:39:0004 September 2022 20:39:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Specified System Activation ENS 558212022-04-05T06:23:0005 April 2022 06:23:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Scram on LOW Level ENS 540352019-04-29T20:33:00029 April 2019 20:33:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to Power Oscillations and High Pressure Coolant Injection System Initiation ENS 539982019-04-14T04:03:00014 April 2019 04:03:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram and Specified System Actuation ENS 533952018-05-10T06:48:00010 May 2018 06:48:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Valid Emergency Diesel Start on Partial Loss of Offsite Power ENS 529502017-09-06T15:57:0006 September 2017 15:57:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram on Low Reactor Vessel Water Level ENS 524252016-12-10T13:48:00010 December 2016 13:48:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to High Main Turbine Vibrations ENS 513692015-09-04T13:16:0004 September 2015 13:16:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unplanned Automatic Scram and Specified System Actuations Due to Msiv Closure ENS 498322014-02-16T17:16:00016 February 2014 17:16:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Unit 2 Experienced a Partial Loss of Offsite Power with Autostart of Division I and III Edgs ENS 485902012-12-13T21:30:00013 December 2012 21:30:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown Due to Primary Containment System Declared Inoperable ENS 484812012-11-06T05:06:0006 November 2012 05:06:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation High Pressure Coolant Injection Actuation Signal ENS 484772012-11-03T12:23:0003 November 2012 12:23:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram on Low Reactor Water Level ENS 484562012-10-30T01:00:00030 October 2012 01:00:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Initiation of Emergency Diesel Generator Due to Loss of One Off-Site Power Source ENS 484532012-10-29T04:00:00029 October 2012 04:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Rps Actuation While Critical Due to Generator Load Reject ENS 483232012-09-20T13:23:00020 September 2012 13:23:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram and High Pressure Coolant Injection System Initiation ENS 481102012-07-17T15:18:00017 July 2012 15:18:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Due to High Neutron Flux ENS 468082011-05-03T00:51:0003 May 2011 00:51:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram ENS 464092010-11-10T15:56:00010 November 2010 15:56:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unplanned Automatic Scram and High Pressure Coolant Injection System Initiation During Testing ENS 454122009-10-05T15:58:0005 October 2009 15:58:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Scram and High Pressure Coolant Injection Following a Loss of Feedwater Level Control ENS 449822009-04-10T09:38:00010 April 2009 09:38:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation High Pressure Coolant Injection Automatic Initiation Due to Turbine Trip ENS 449232009-03-21T05:21:00021 March 2009 05:21:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation High Pressure Coolant Injection System Initiation Following Planned Manual Scram ENS 445982008-10-24T01:26:00024 October 2008 01:26:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to Loss of the Electronic Pressure Regulator ENS 442062008-05-13T12:25:00013 May 2008 12:25:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unusual Event Declared Due to Loss of Offsite Power ENS 426332006-06-12T17:02:00012 June 2006 17:02:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Hpci Inititation Signal Due to Turbine Trip Signal During Startup ENS 419272005-08-18T13:49:00018 August 2005 13:49:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram Due to Loss of a Power Board ENS 415842005-04-10T10:00:00010 April 2005 10:00:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Scram Signal Resulting from Failure of a Supply Valve to the Scram Air Header ENS 409982004-08-30T12:35:00030 August 2004 12:35:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit 1 Manually Scrammed Due to Oscillating Reactor Vessel Water Level ENS 407192004-05-02T06:17:0002 May 2004 06:17:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Manual Scram Due to Rising Torus Temperature Due to Stuck Open Erv ENS 406842004-04-18T22:30:00018 April 2004 22:30:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Residual Heat Removal System Isolation Due to a Rise in Reactor Pressure ENS 403222003-11-14T02:49:00014 November 2003 02:49:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Loss of 115 Kv Line Results in Emergency Diesel Generator Auto-Start 2024-03-04T00:42:00 | |