ENS 44935
From kanterella
Jump to navigation
Jump to search
ENS Event | |
|---|---|
08:52 Mar 26, 2009 | |
| Title | Automatic Reactor Trip and Aux Feed Water Start Due to Loss of an Off Site Power Source |
| Event Description | At approximately 0452 on 03/26/09, Sequoyah Unit 2 received an Automatic Reactor trip on Reactor Coolant Pump Busses Undervoltage. A loss of Common Service Station Transformer C caused a loss of power to the 2B and 2D Unit Boards. The 2B and 2D unit boards are the 6.9Kv electrical feeds to the 2-2 and 2-4 RCPs, respectively. RCPs 2-1 and 2-3 are running.
ESF functions initiated as designed including Aux Feed Water auto-start, automatic Feedwater isolation, and auto-start of all four EDGs. The 2A Shutdown Board is being powered from the 2A EDG. The plant is currently being maintained in Mode 3 at approximately 547 degrees F /2235 PSIG. Decay heat is being removed by the auxiliary feedwater system and Steam Generator Atmospheric Relief valves. The cause of the loss of Common Service Station Transformer C is not known at this time and investigation is ongoing. All rods inserted as expected. No safety related equipment is out of service. Unit 2 has no known Steam Generator Tube leaks. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Sequoyah  Tennessee (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+-0.38 h-0.0158 days <br />-0.00226 weeks <br />-5.20524e-4 months <br />) | |
| Opened: | Bruce Buch 08:29 Mar 26, 2009 |
| NRC Officer: | Jason Kozal |
| Last Updated: | Mar 26, 2009 |
| 44935 - NRC Website
Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 44935\u003C/a\u003E - \u003Ca href=\"/Sequoyah\" title=\"Sequoyah\"\u003ESequoyah\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EAutomatic Reactor Trip and Aux Feed Water Start Due to Loss of an Off Site Power Source\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 44935 - Sequoyah\n","link":"","lat":35.22651944444444,"lon":-85.09192777777778,"icon":"/w/images/c/ce/Tennessee_Valley_Authority_icon.png"}],"imageoverlays":null} | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | A/R |
| Before | Power Operation (100 %) |
| After | Hot Standby (0 %) |
Sequoyah with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 573512024-09-29T09:56:00029 September 2024 09:56:00
[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 Trip Due to Turbine Trip ENS 572852024-08-23T16:19:00023 August 2024 16:19:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip ENS 572532024-07-30T20:41:00030 July 2024 20:41:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Turbine Trip ENS 552722021-05-24T13:16:00024 May 2021 13:16:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation on 5/24/21 at 0916 Edt, an Automatic Reactor Trip on Unit 1 Occurred. All Safety Systems Responded Normally and the Plant Is Currently Stable in Mode 3 (Hot Standby) at Normal Operating Temperature and Pressure. Preliminary Indications Are That the Unit Trip Was Caused by a High Neutron Flux Rate Detected by the Power Range Nuclear Instruments. Troubleshooting and Investigation Are Ongoing to Determine the Initiating Cause. ENS 544462019-12-16T08:58:00016 December 2019 08:58:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Emergency Diesel Generator Autostart Due to Loss of Power to 1B Shutdown Board ENS 544382019-12-12T09:33:00012 December 2019 09:33:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation ENS 542422019-08-27T05:09:00027 August 2019 05:09:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip ENS 539992019-04-14T07:20:00014 April 2019 07:20:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation En Revision Imported Date 8/7/2019 ENS 527692017-05-24T03:30:00024 May 2017 03:30:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation All Four Edgs Autostarted During Transfer of Shutdown Board to Normal Power Source for Unit 2 Testing ENS 524692016-12-30T18:05:00030 December 2016 18:05:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Control Rod Not Withdrawing as Expected ENS 517202016-02-09T19:15:0009 February 2016 19:15:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Eccs Discharge to Rcs Via Charging System ENS 515592015-11-23T13:44:00023 November 2015 13:44:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip After Partial Msiv Closure ENS 513922015-09-14T08:26:00014 September 2015 08:26:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Loss of Power to Vital Instrument Board ENS 512652015-07-27T14:43:00027 July 2015 14:43:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor/Turbine Trip ENS 512592015-07-24T17:51:00024 July 2015 17:51:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Turbine Trip on Main Generator Lockout ENS 508782015-03-11T10:21:00011 March 2015 10:21:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to a Nuclear Instrumentation Signal ENS 508562015-03-02T11:45:0002 March 2015 11:45:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip ENS 487782013-02-24T17:05:00024 February 2013 17:05:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Loss of Condenser Vacuum Indication ENS 481982012-08-16T23:26:00016 August 2012 23:26:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Trip from a Reactor Coolant Pump Trip ENS 471692011-08-19T02:50:00019 August 2011 02:50:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Reactor Coolant Pump Bus Undervoltage ENS 470812011-07-21T01:29:00021 July 2011 01:29:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Negative Rate Trip Following Rapid Turbine Load Reduction ENS 469912011-06-26T20:14:00026 June 2011 20:14:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Turbine Trip ENS 464922010-12-20T05:50:00020 December 2010 05:50:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to a Fire in the Main Generator Bus Duct ENS 464242010-11-17T03:10:00017 November 2010 03:10:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Based on Decreasing Steam Generator Level ENS 455202009-11-26T07:42:00026 November 2009 07:42:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Trip Due to Loss of Vacuum on Turbine Driven Feedwater Pump ENS 450972009-05-27T23:04:00027 May 2009 23:04:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Trip from Power Range High Neutron Flux Rate ENS 450452009-05-07T02:56:0007 May 2009 02:56:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Feed Regulating Valve Failure ENS 450292009-04-29T01:59:00029 April 2009 01:59:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Initiated as a Result of a Loss of Condensate Flow ENS 449342009-03-26T08:52:00026 March 2009 08:52:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip and Aux Feed Water Start Due to Loss of an Off Site Power Source ENS 449352009-03-26T08:52:00026 March 2009 08:52:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip and Aux Feed Water Start Due to Loss of an Off Site Power Source ENS 446492008-11-09T23:21:0009 November 2008 23:21:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Trip Breakers Opened Manually Due to Indicated Dropped Control Rod ENS 446272008-11-04T04:22:0004 November 2008 04:22:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Trip Due to Feedwater Reg Valve Failure ENS 439092008-01-17T00:25:00017 January 2008 00:25:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Lowering Steam Generator Level ENS 432332007-03-13T19:27:00013 March 2007 19:27:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to "a" Main Feedwater Pump ENS 431152007-01-23T17:44:00023 January 2007 17:44:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Trip Due to Feedwater Regulating Valve Failure ENS 424442006-03-22T21:24:00022 March 2006 21:24:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Turbine Trip / Reactor Trip Caused by Main Generator Trip ENS 415832005-04-09T15:11:0009 April 2005 15:11:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip on Turbine Trip Due to Low Auto Stop Oil Pressure on Pressure Switches ENS 414372005-02-24T02:06:00024 February 2005 02:06:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip on Low-Low Steam Generator Level ENS 405892004-03-15T20:18:00015 March 2004 20:18:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Main Generator Electrical Fault Signal ENS 404752004-01-25T08:16:00025 January 2004 08:16:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unplanned Auto Start of Turbine Driven Auxiliary Feedwater Pump ENS 403052003-11-10T04:15:00010 November 2003 04:15:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Sequoyah Unit 2 Auxiliary Feedwater Actuation During Outage ENS 401132003-08-28T20:04:00028 August 2003 20:04:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Alert Declared Due to Reactor Protection System Failure 2024-09-29T09:56:00 | |
Retrieved from "https://kanterella.com/w/index.php?title=ENS_44935&oldid=425947"