ENS 47478
ENS Event | |
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08:38 Nov 27, 2011 | |
Title | Unusual Event Due to a Loss of Offsite Power During Switching Operations |
Event Description | At 0238, Point Beach Unit 1, classified an Unusual Event based on CU3.1, loss of power to or from the 1X-04 transformer that results in a loss of all offsite power to both safety-related busses 1A-05 and 1A-06 for greater than 15 minutes and at least one emergency [diesel] generator is supplying power to an emergency bus.
The 1X-04 transformer converts 345 kV to 13.8 kV. Both Emergency Diesel Generators are running supplying the safety-related busses. The licensee notified State and local agencies and the NRC Resident Inspector.
Off-site power to Unit 1A-05 and 1A-06 Safeguards Busses has been restored via Unit 2 2X-03 High Voltage Station Transformer and 1X-04 Low Voltage Station Transformer. During the transient, all four Emergency Diesel Generators (EDGs) started as expected with G-01 EDG supplying the Unit 1 1A-05 Safeguards Bus and G-03 EDG supplying 1A-06 Safeguards Bus. Off-site power to the Unit 2 Safeguards Buses was not affected. The start of the EDGs is also reportable under 10CFR 50.72 (b)(3)(iv)(A). All systems responded as designed during the transient and operators performed in accordance with procedures and their training. Unit 1 is stable in Mode 5 within normal operating bands. Unit 2 remains operating at 100% power. The Unusual Event was terminated at 0700 [CST] on November 27, 2011. A press release is planned. The licensee has notified State and local agencies and the NRC Resident Inspector. Notified R3DO (Julio Lara), IRD MOC (Jane Marshall), NRR EO (Sher Bahadur), DHS (Rickerson), and FEMA (Hollis). |
Where | |
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Point Beach Wisconsin (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 | |
Time - Person (Reporting Time:+-4.27 h-0.178 days <br />-0.0254 weeks <br />-0.00585 months <br />) | |
Opened: | Rick Robbins 04:22 Nov 27, 2011 |
NRC Officer: | Mark Abramovitz |
Last Updated: | Nov 27, 2011 |
47478 - NRC Website
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Unit 1 | |
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Reactor critical | Not Critical |
Scram | No |
Before | Cold Shutdown (0 %) |
After | Cold Shutdown (0 %) |
Point Beach with 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 553902021-07-31T21:46:00031 July 2021 21:46:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip of Unit 1 ENS 537792018-12-05T06:00:0005 December 2018 06:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip on Loss of Main Condenser Vacuum ENS 530042017-10-09T12:37:0009 October 2017 12:37:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declaration for Toxic Gas Spill ENS 526272017-03-20T21:20:00020 March 2017 21:20:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared for Fire Alarm in Containment ENS 515702015-11-29T01:12:00029 November 2015 01:12:00 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 Generator Lockout After Voltage Regulator Malfunction ENS 515062015-10-29T08:48:00029 October 2015 08:48:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Actuation of the Auxiliary Feedwater System Due to Main Transformer Lockout ENS 506492014-12-03T02:50:0003 December 2014 02:50:00 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 Failure of Condensate Pump ENS 494332013-10-13T14:46:00013 October 2013 14:46:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration ENS 487222013-02-06T17:43:0006 February 2013 17:43:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unusual Event - Loss of Offsite Power to Essential Buses for Greater than 15 Minutes ENS 481892012-08-15T01:31:00015 August 2012 01:31:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit 1 Manually Tripped in Anticipation of an Automatic Turbine Trip ENS 480532012-06-28T01:46:00028 June 2012 01:46:00 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 100% Load Reject ENS 478632012-04-26T02:06:00026 April 2012 02:06:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Alert Declared Due to Toxic Gas Build Up Following an Emergency Diesel Generator Test Run ENS 474782011-11-27T08:38:00027 November 2011 08:38:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unusual Event Due to a Loss of Offsite Power During Switching Operations ENS 464822010-12-15T07:48:00015 December 2010 07:48:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit 2 Manual Reactor Trip During Startup ENS 461292010-07-27T01:01:00027 July 2010 01:01:00 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 ENS 460802010-07-09T11:47:0009 July 2010 11:47:00 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 Feedwater Regulating Valve Failure ENS 460322010-06-19T11:36:00019 June 2010 11:36:00 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 Generator Lockout ENS 443362008-07-04T00:45:0004 July 2008 00:45:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Sodium Hypochlorite Leak ENS 439072008-01-15T20:15:00015 January 2008 20:15:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Unusual Event - Loss of Offsite Power ENS 434072007-06-05T20:17:0005 June 2007 20:17:00 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 Feedwater Valve Failure ENS 429122006-10-17T02:26:00017 October 2006 02:26:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event - Identified Leakage Greater than 25 Gpm ENS 407542004-05-15T16:54:00015 May 2004 16:54:00 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 Diver Entangled in Intake Crib 2021-07-31T21:46:00 | |