ENS 48221
ENS Event | |
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12:01 Aug 22, 2012 | |
Title | Automatic Reactor Trip Due to High Reactor Coolant System Pressure |
Event Description | On August 22, 2012, during a planned load reduction, Three Mile Island Unit 1 Reactor automatically tripped at 0801 EDT due to high reactor coolant system pressure as a result of a main feedwater transient. The cause of the main feedwater transient is still under investigation. The Emergency Feedwater System (EFW) actuated at 0801 EDT.
The electrical grid is stable and Unit 1 is being supplied by offsite power. All control rods fully inserted. Decay heat is being removed via the Emergency Feedwater System (EFW) flow to both Steam Generators that are exhausting via the normal main condenser cooling loop under manual control. Preliminary evaluation indicates all plant systems functioned normally following the reactor trip and EFW actuation except for manual operation of Turbine Bypass Valve control due to failure of the automatic control function. Three Mile Island Unit 1 remains stable in Hot Shutdown mode while conducting the post trip review. No radioactive releases were experienced as a result of this event. This event is reportable under 10 CFR 50.72(b)(2)(iv)(B), Reactor Protection System (RPS) actuation, and under 10 CFR 50.72(b)(2)(xi), due to an information release to local officials, both are four (4) hour reports. This event is also reportable under 10 CFR 50.72(b)(3)(iv)(A) and 10 CFR 50.72(b)(3)(iv)(B), due to a valid actuation of the Emergency Feedwater System. The licensee notified the NRC Resident Inspector." Licensee notified the State, local and other Government agencies. |
Where | |
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Three Mile Island Pennsylvania (NRC Region 1) | |
Reporting | |
10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
LER: | 05000289/LER-2012-004 |
Time - Person (Reporting Time:+-0.48 h-0.02 days <br />-0.00286 weeks <br />-6.57504e-4 months <br />) | |
Opened: | Kevin Coughlin 11:32 Aug 22, 2012 |
NRC Officer: | Dong Park |
Last Updated: | Aug 22, 2012 |
48221 - NRC Website
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Unit 1 | |
---|---|
Reactor critical | Critical |
Scram | A/R |
Before | Power Operation (30 %) |
After | Hot Shutdown (0 %) |
Three Mile Island with 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 565602023-06-06T13:37:0006 June 2023 13:37:00
[Table view]10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Offsite Notification Due to ON-SITE Fatality ENS 554552021-09-10T14:55:00010 September 2021 14:55:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 72.75(b)(2), Offsite Notification Offsite Notification Due to Contractor Fatality ENS 542832019-09-17T14:28:00017 September 2019 14:28:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release On-Site Non-Work Related Fatality ENS 533232018-04-11T09:42:00011 April 2018 09:42:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Offsite Notification Due to Hydrazine Spill ENS 529272017-08-25T15:15:00025 August 2017 15:15:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Offsite Notification Due to Exceeding Chlorine Effluent Limit ENS 506542014-12-04T16:50:0004 December 2014 16:50:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Offsite Notification Due to Emergency Siren Inadvertently Sounding ENS 483252012-09-20T18:16:00020 September 2012 18:16:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Trip Due to Reactor Protection System Actuation ENS 482212012-08-22T12:01:00022 August 2012 12:01:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 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 High Reactor Coolant System Pressure ENS 481322012-07-25T18:30:00025 July 2012 18:30:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Press Release Due to an Elevated Level of Tritium Detected on Site ENS 470482011-07-14T17:19:00014 July 2011 17:19:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Offsite Notification Due to Inadvertant Siren Actuation ENS 455142009-11-22T03:45:00022 November 2009 03:45:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Radiation Release in Containment Associated with Steam Generator Removal ENS 430502006-12-13T22:48:00013 December 2006 22:48:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Unit Reactor Trip Due to Grid Disturbance ENS 429572006-11-02T18:34:0002 November 2006 18:34:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Turbine Trip/ Reactor Trip Due to Invalid Low Condenser Vacuum Signal ENS 402442003-10-13T15:20:00013 October 2003 15:20:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Offsite Notification to Osha at Three Mile Island Regarding a Fatality ENS 401782003-09-19T06:24:00019 September 2003 06:24:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Siren Capability Due to Adverse Weather Conditions 2023-06-06T13:37:00 | |