ENS 52950
ENS Event | |
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15:57 Sep 6, 2017 | |
Title | |
Event Description | On September 6, 2017 at 1157 [EDT], Nine Mile Point Unit 1 experienced an automatic reactor scram with a Main Steam Isolation Valve (MSIV) and Containment isolation. The scram was due to reactor vessel low water level. The cause of the reactor vessel low water level is under investigation. All control rods fully inserted. Following the scram, pressure was momentarily controlled through the use of the Emergency Condenser (EC) system. At 1205, pressure control was established through the main steam lines to the condenser through the turbine bypass valves. All plant systems responded per design following the scram. The reactor scram is a 4-hour report per 10 CFR 50.72(b)(2)(iv)(B).
The following systems automatically actuated after the scram as expected. These system actuations are an 8-hour report per 10 CFR 50.72(b)(3)(iv)(A): 1. The High Pressure Coolant Injection (HPCI) system. HPCI initiated at 1157 and was reset at 1158 when RPV level was restored above the HPCI system low level actuation set point. HPCI is a flow control mode of the normal feedwater systems, and is not an Emergency Core Cooling System. 2. The Core Spray system actuated, but did not discharge to the Reactor Coolant system. The Core Spray system was secured at 1216. 3. Containment and MSIV isolation on reactor vessel low-low water level signal. Nine Mile Point Unit 1 is currently in Hot Shutdown, with reactor vessel water level and pressure maintained within normal bands. Decay heat is being removed via steam to the main condenser using the turbine bypass valves. The offsite grid is stable with no grid restrictions or warnings in effect. The licensee has notified the NRC Resident Inspector. No safety relief valves lifted during the transient. The main steam isolation valves were opened after the isolation signal cleared to facilitate decay heat removal. Offsite power is supplying all plant loads. There was no effect on Unit 2. The licensee notified New York State Department of Environmental Protection and will be issuing a press release. |
Where | |
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Nine Mile Point New York (NRC Region 1) | |
Reporting | |
10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
LER: | 05000220/LER-2017-003 |
Time - Person (Reporting Time:+-0.27 h-0.0113 days <br />-0.00161 weeks <br />-3.69846e-4 months <br />) | |
Opened: | Jason Quick 15:41 Sep 6, 2017 |
NRC Officer: | Howie Crouch |
Last Updated: | Sep 6, 2017 |
52950 - NRC Website | |
Unit 1 | |
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Reactor critical | Critical |
Scram | A/R |
Before | Power Operation (100 %) |
After | Hot Shutdown (0 %) |
Nine Mile Point with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 570042024-03-04T00:42:0004 March 2024 00:42:00
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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 535652018-08-27T04:00:00027 August 2018 04:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation En Revision Imported Date 8/29/2018 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 528892017-08-06T02:35:0006 August 2017 02:35:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram During Testing ENS 526242017-03-20T06:27:00020 March 2017 06:27:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Scram Due to Pressure Oscillations 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 508302015-02-18T19:06:00018 February 2015 19:06:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Scram Due to Rapidly Rising Reactor Water Level ENS 498882014-03-10T20:28:00010 March 2014 20:28:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Scram Due to Actuation of the Alternate Rod Insertion System ENS 498682014-03-04T06:43:0004 March 2014 06:43:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Unit 2 Manual Reactor Scram Following Loss of a Uninterruptible Power Supply (Ups) 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 495932013-12-02T14:04:0002 December 2013 14:04:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Scram Following Trip of Both Reactor Recirculation Pumps 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 480972012-07-12T06:20:00012 July 2012 06:20:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Lowering Condenser Vacuum ENS 471412011-08-11T04:16:00011 August 2011 04:16:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Inserted Due to a Feedwater Leak on a Min Flow Line 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 456122010-01-07T06:00:0007 January 2010 06:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram During Transmitter Venting 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 424032006-03-10T03:14:00010 March 2006 03:14:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Due to Loss of Condenser Vacuum Turbine Trip 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 414642005-03-07T09:37:0007 March 2005 09:37:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Automatic Turbine Trip/ Reactor Scram 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 | |