ENS 45245
ENS Event | |
---|---|
14:50 Aug 5, 2009 | |
Title | Unusual Event Declared Due to Toxic Gas from a Switchgear Fire in the Turbine Building |
Event Description | At 0750 PDT the licensee experienced a turbine trip and reactor scram. At approximately the same time, a fire was detected in the non-safety related 6.9 kV feed bus to switchgear SH-5 and SH-6 in the turbine building. The fire and associated fault to the switchgear feed bus caused a loss of power to both reactor recirculation pumps and the automatic reactor scram. The fire produced smoke and potentially toxic gases. Due to the presence of potentially toxic gas in the power plant, an Unusual Event was declared at 0812 PDT based on EAL 9.3.U.3. At the present time, the fire is out and the smoke is being cleared from the plant.
All rods fully inserted upon the reactor scram. Systems functioned as expected except for problems with the EHC system which resulted in the bypass valves remaining open which caused the reactor to depressurize to approximately 390 psi. MSIVs were manually shut to halt the reactor depressurization and cooldown. Decay heat is being removed via relief valves to the suppression pool with reactor pressure being maintained between 500 and 600 psi. Suppression pool cooling is via RHR. Makeup water to the reactor is via normal feed. Licensee is on natural circulation at the time of this report. Normal shutdown electrical alignment is established with the exception of Division II emergency switchgear which is aligned to the backup transformer. A request for assistance was made to the Hanford fire department, however, the fire was out prior to their arrival on site. The licensee has notified State, local agencies and the NRC Resident Inspector.
The Unusual Event has been terminated as of 1006 PDT. The licensee is taking the unit to cold shutdown. The licensee will notify the NRC Resident Inspector. Notified NRR EO (Ross-Lee), R4DO (Walker), DHS (Enzer), and FEMA (Eaches).
Following the reactor scram, with the turbine bypass valves failed fully open, the inboard main steam isolation valves had to be manually closed to prevent excessive cool down. The outboard main steam isolation valves automatically closed from the inability to maintain condenser vacuum. The inability to maintain condenser vacuum was due to limited equipment access in the Turbine Building from heavy smoke. This is reportable under Part 50.72(b)(3)(iv)(A) as a valid actuation of one of the systems listed in Part 50.72(b)(3)(iv)(B)(2). The licensee notified the NRC Resident Inspector. Notified R4DO (Walker). |
Where | |
---|---|
Columbia Generating Station Washington (NRC Region 4) | |
Reporting | |
Emergency class: | Unusual Event |
10 CFR 50.72(a) (1) (i), Emergency Class Declaration 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
Time - Person (Reporting Time:+-2.83 h-0.118 days <br />-0.0168 weeks <br />-0.00388 months <br />) | |
Opened: | John Slack 12:00 Aug 5, 2009 |
NRC Officer: | Donald Norwood |
Last Updated: | Aug 5, 2009 |
45245 - 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 45245\u003C/a\u003E - \u003Ca href=\"/Columbia\" title=\"Columbia\"\u003EColumbia\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EUnusual Event Declared Due to Toxic Gas from a Switchgear Fire in the Turbine Building\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 45245 - Columbia\n","link":"","lat":46.55068333333333,"lon":-119.488975,"icon":"/w/images/7/7c/Energy_Northwest_icon.png"}],"imageoverlays":null} | |
Unit 2 | |
---|---|
Reactor critical | Critical |
Scram | A/R |
Before | Power Operation (100 %) |
After | Hot Shutdown (0 %) |
Columbia with 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 | |
WEEKMONTHYEARENS 559382022-06-13T16:23:00013 June 2022 16:23:00
[Table view]10 CFR 50.72(b)(3)(iv)(A), System Actuation Partial Loss of Power to RPS During Maintenance ENS 534102018-05-18T13:51:00018 May 2018 13:51:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Caused by Main Transformer Trip ENS 529182017-08-20T23:05:00020 August 2017 23:05:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to a Rise in Main Condenser Back Pressure ENS 524422016-12-18T19:24:00018 December 2016 19:24:00 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 Scram Due to Load Reject from Substation ENS 518262016-03-28T20:22:00028 March 2016 20:22:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Scram Following Loss of Reactor Closed Cooling ENS 510862015-05-22T07:14:00022 May 2015 07:14:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Emergency Diesel Generator Start Due to Actuation of Undervoltage Circuitry ENS 491202013-06-15T19:22:00015 June 2013 19:22:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Division 1 and 2 Emergency Diesel Generators Power Buses After Momentary Offsite Power Loss ENS 467392011-04-07T23:07:0007 April 2011 23:07:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Hydrogen Burn During Maintenance ENS 454842009-11-07T15:25:0007 November 2009 15:25:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to a Main Turbine Digital Electro-Hydraulic Control System Leak ENS 452452009-08-05T14:50:0005 August 2009 14:50:00 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 Unusual Event Declared Due to Toxic Gas from a Switchgear Fire in the Turbine Building ENS 451692009-06-27T03:05:00027 June 2009 03:05:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Based on Fire Lasting Greater than 15 Minutes ENS 450512009-05-08T17:45:0008 May 2009 17:45:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram After Loss of Generator Seal Oil ENS 448392009-02-08T19:25:0008 February 2009 19:25:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Due to a Governor Valve Fast Closure Signal ENS 444322008-08-21T23:06:00021 August 2008 23:06:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Due to a Main Turbine Trip ENS 434572007-06-29T00:17:00029 June 2007 00:17:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Trip Due to Condensate Pump Trip ENS 432902007-04-07T20:44:0007 April 2007 20:44:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Fire in the Reactor Protection System Division 2 Equipment Room ENS 429502006-10-31T12:45:00031 October 2006 12:45:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Trip from Turbine Trip on Low Auto Stop Oil Pressure ENS 424502006-03-28T21:57:00028 March 2006 21:57:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Due to Range Brush Fire Near Plant ENS 417922005-06-24T06:21:00024 June 2005 06:21:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Licensee Declared an Unusual Event Due to Detection of a Flammable Gas in the General Services Building ENS 417902005-06-23T20:46:00023 June 2005 20:46:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit Experienced an Automatic Reactor Scram Due to a Loss of Feedwater Flow ENS 417792005-06-15T21:00:00015 June 2005 21:00:00 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 Turbine Throttle Valve Closure ENS 415652005-04-06T00:12:0006 April 2005 00:12:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Under E.A.L. 9-3.U.1 ENS 409642004-08-17T12:28:00017 August 2004 12:28:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Trip of Reactor Feedwater Pump "a" on Low Suction Pressure. ENS 409592004-08-15T20:03:00015 August 2004 20:03:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Reactor Feedwater Pump Trip ENS 409102004-07-30T17:00:00030 July 2004 17:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Alert Declared at Columbia Generating Station 2022-06-13T16:23:00 | |