ENS 51061
ENS Event | |
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22:55 May 9, 2015 | |
Title | Unusual Event Declared Due to Steam Leak in the Turbine Building |
Event Description | At 1855 EDT, a steam leak from the #1 moisture separator reheater in the turbine building was reported to the control room. Operators performed a rapid down power to approximately 30% at which time the reactor was manually tripped. At 1910 EDT an Unusual Event was declared. The steam feed rupture control system was manually initiated (this includes actuation of both turbine-driven Auxiliary Feedwater Pumps) and the steam leak was isolated. Station air compressor #2 (non-safety related) tripped. Station air compressor #1 automatically started.
The unit is currently in mode 3 (Hot Standby) and stable. Steam is being discharged through the atmospheric dumps as a means of decay heat removal. There is no known primary to secondary leakage. All systems functioned as expected. There were no reported injuries and personnel accountability is in progress. The licensee notified state and local agencies and informed the NRC Resident Inspector. Notified DHS SWO, FEMA Ops Center, NICC Watch Officer and FEMA NWC and NuclearSSA via email.
The licensee exited the Unusual Event at 2121 EDT based on the following: At 2121 hours0.0245 days <br />0.589 hours <br />0.00351 weeks <br />8.070405e-4 months <br /> EDT, the Unusual Event at the Davis-Besse Nuclear Power Station was terminated. The steam leak has been isolated and plant conditions are stable. Cooling continues to be maintained via the auxiliary feedwater system. The initiation of auxiliary feedwater at the start of the event is reportable as a Specified System Actuation per 10CFR50.72(b)(3)(iv)(A). The licensee notified state and local agencies and informed the NRC Resident Inspector. Notified R3DO (Skokowski), NRR EO (Morris) and IRD (Grant). Notified DHS SWO, FEMA Ops Center, NICC Watch Officer and FEMA NWC and NuclearSSA via email. |
Where | |
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Davis Besse Ohio (NRC Region 3) | |
Reporting | |
Emergency class: | Unusual Event |
10 CFR 50.72(a) (1) (i), Emergency Class Declaration 10 CFR 50.72(b)(3)(iv)(A), System Actuation 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation | |
LER: | 05000346/LER-2015-002 |
Time - Person (Reporting Time:+-3.17 h-0.132 days <br />-0.0189 weeks <br />-0.00434 months <br />) | |
Opened: | John Phillippe 19:45 May 9, 2015 |
NRC Officer: | John Shoemaker |
Last Updated: | May 9, 2015 |
51061 - NRC Website
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Unit 1 | |
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Reactor critical | Critical |
Scram | Yes, Manual Scram |
Before | Power Operation (100 %) |
After | Hot Standby (0 %) |
Davis Besse 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 553462021-07-09T01:54:0009 July 2021 01:54:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Trip Due to Main Turbine Trip ENS 546112020-03-25T16:40:00025 March 2020 16:40:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Trip Due to Loss of Reactor Coolant Pumps ENS 542632019-09-07T17:09:0007 September 2019 17:09:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Trip ENS 522322016-09-10T07:43:00010 September 2016 07:43:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Unit Trip Due to Main Generator Lock-Out ENS 517022016-01-30T06:23:00030 January 2016 06:23:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unanticipated Sfrcs Actuation While Restoring Main Feedwater to Steam Generators ENS 516962016-01-29T18:22:00029 January 2016 18:22:00 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 Protection System Actuation ENS 514832015-10-21T00:24:00021 October 2015 00:24:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Due to Suspicious Vehicle in Owner Controlled Area ENS 510612015-05-09T22:55:0009 May 2015 22:55:00 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 Steam Leak in the Turbine Building ENS 502632014-07-08T13:25:0008 July 2014 13:25:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Due to Smoke Alarm Inside Containment ENS 500862014-05-05T18:56:0005 May 2014 18:56:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram with Rod Motion While Shutdown ENS 500972014-05-04T12:32:0004 May 2014 12:32:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Initiation of the Reactor Protection System While Shutdown ENS 491592013-06-30T01:20:00030 June 2013 01:20:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Trip Due to Reactor Coolant Pump Trip ENS 474432011-11-16T07:22:00016 November 2011 07:22:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Alert Due to Fire in Electrical Bus Affecting Safety Related Equipment ENS 465512011-01-19T07:32:00019 January 2011 07:32:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Notification of Unusual Event Due to a Fire and Explosions in the Protected Area ENS 451622009-06-25T04:49:00025 June 2009 04:49:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Discovery of an After-The-Fact Alert Due to Catastrophic Failure of Ccpd ENS 428282006-09-06T06:31:0006 September 2006 06:31:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Trip on Loss of Condenser Vacuum ENS 413302005-01-13T14:49:00013 January 2005 14:49:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Entry Into Technical Specification Required Shut Down Due to Loss of Essential Bus ENS 409212004-08-04T14:24:0004 August 2004 14:24:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Unexpected Reactor Trip During Maintenance Activities ENS 402082003-10-01T01:34:0001 October 2003 01:34:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Valid Specified System Actuation ENS 401612003-09-16T04:30:00016 September 2003 04:30:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Coolant System Pressure Increase Caused a Valid Signal ENS 400702003-08-14T20:10:00014 August 2003 20:10:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to a Loss of Offsite Power. 2021-07-09T01:54:00 | |