Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 46212 | 29 August 2010 23:05:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Declared Due to Loss of Annuciators in the Control Room | At 1905 EST, Vermont Yankee declared a Notice of an Unusual Event (NOUE) based on EAL SU 4.1, loss of 75% of the control room annunciators associated with safety related systems for greater than 15 minutes. Around 1845 EST, several annunciators were received and based on the failure mode, the licensee conservatively estimated that greater than 75% of the annunciators in the control room were inoperable. The licensee will notify the NRC Resident Inspector.
The licensee determined that the cause of the annunciator loss was a blown fuse. The fuse was replaced and the annunciators were restored without further issues. Vermont Yankee exited the NOUE at 2028 EST. The licensee has notified State authorities and will notify NRC Resident Inspector. Notified R1DO (Henderson), NRR EO (Evans), IRD (Gott), DHS (Vestal), and FEMA (Visce). | ||
| ENS 46038 | 23 June 2010 18:25:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Declared Due to an Earthquake Felt Onsite | Event Description: An Unusual Event was declared at 1425 EDT due to reports from site personnel of an earthquake felt onsite. This was verified through the National Earthquake Information Center. Plant seismic monitors did not actuate. Actions Taken: Implemented OP 3127, Natural Phenomenon, for an earthquake. Plant personnel are walking down systems for any damage indications. (There is no indication of damage) at this time." The licensee informed state/local agencies and the NRC Resident Inspector. The licensee plans to issue a press release.
The Unusual Event was terminated at 1725 EDT. Plant walkdowns were completed with no damage noted. The licensee notified the NRC Resident Inspector. Notified the R1DO (Dwyer), NRR EO (Cunningham), DHS (Inzer), and FEMA (Hollis). | ||
| ENS 42605 | 25 May 2006 01:02:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event for a Fire Lasting Greater than Ten Minutes | Licensee declared an Unusual Event due to a fire that was not extinguished within 10 minutes - EAL U4A. There were no flames, only smoke. Control Room received a Bus 2 ground alarm, reduced power, secured the B Main Feedwater Pump, inserted control rods below the Maximum Extended Load Limit Analysis (MELLA) line, and then secured the C Condensate Pump. The ground alarm cleared after securing the C Condensate Pump. CO2 discharged automatically into the switchgear room due to the smoke in the switchgear room. The switchgear room has been ventilated, site personnel have entered and no other damage to the switchgear has been identified other than the C Condensate pump breaker. Offsite Fire (Vernon Fire Department) responded to the site and is assisting with ventilation. One ambulance is responding to transport a Fire Brigade member that is not feeling well due to heat. The licensee has notified the NRC Resident Inspector, and State and Local emergency response organizations. Notified R1 PAO (Screnci).
Licensee called to terminate the Unusual Event. The plant is in a stable condition with no other outstanding problems. Ventilation of the switchgear room is continuing and air samples are being analyzed. The licensee has notified the NRC Resident Inspector, and State and Local emergency response organizations. Notified R1 (Holian, Powell, Bores), IRD (Blount), NRR EO (Haney), R1DO (Gray), DHS (Lee) and FEMA (Casto) | Feedwater Control Rod | |
| ENS 40827 | 18 June 2004 10:50:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Declared Due to a Main Transformer Fire Lasting Fire Longer than 10 Minutes. | Main transformer fire caused a load rejection/automatic reactor scram. All rods fully inserted into the core. Offsite power is being supplied through their startup transformers. Offsite fire department, Vernon, responded with three fire trucks and one ambulance. Main transformer fire was extinguished at 0751 EDT. There were no personnel injuries. All emergency core cooling systems and their emergency diesel generators are fully operable if needed. Reactor vessel water level is being maintained at its proper level via the condensate and feedwater system. Both recirculation pumps tripped. Licensee is looking into the reason why the recirculation pumps tripped. There was no release of radioactivity from the plant. Licensee notified the states of New Hampshire, Vermont , Massachusetts and local surrounding counties of the declaration of an unusual event. The NRC Resident Inspector was on scene when the event occurred.
At 1245 hrs. EDT, the Licensee terminated the Unusual Event. The basis for the termination was that the fire is out, a reflash watch is established and the plant is stable. The hydrogen in the generator is depressurized and the plant is currently purging the generator with carbon dioxide. The licensee has notified the NRC Resident Inspector. The Headquarters Operations Officer has notified R1DO (Dimitriadis), NRR EO (Reis), FEMA, DHS, DIRO (Wessman), HQPAO (Gagner), DIRO (Andrews), R1 (Blough and Wiggins).
The Licensee has amended the initial report statement: "There was no release of radioactivity from the plant." to read "There was no release of radioactivity related to this event". The licensee has notified the NRC Resident Inspector. Headquarters Operations notified R1DO (Dimitriadis) and NRR EO (Reis). | Feedwater Emergency Diesel Generator Main Transformer Emergency Core Cooling System | 05000271/LER-2004-003 |