|Start date||Reporting criterion||Title||Event description||System||LER|
|ENS 51483||21 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|
Security condition in the Owner Controlled Area outside of the Protected Area. (There is) an unknown vehicle located on the South side of the Intake Canal. The vehicle is locked, the engine is not running, and the parking lights are on. Security is performing an inspection of the vehicle for explosives or other contraband in conjunction with local law enforcement. The Unusual Event was declared based on EAL HU-1. The licensee notified the NRC Resident Inspector. The licensee notified State and local government agencies. Notified (via phone and E-mail): DHS SWO, FEMA Ops Center, and NICC Watch Officer. Notified (via E-mail): FEMA NWC and NuclearSSA.
At 2229 EDT, the Unusual Event for a Security Condition at Davis-Besse Nuclear Power Station was terminated. An inspection of the vehicle in question was performed and it was determined that no threat existed to the site at any time. The licensee notified the NRC Resident Inspector. The licensee notified State and local government agencies. Notified R3DO (Daley), IRD (Stapleton), NRR (Morris) and ILTAB (Tucker). Notified (via phone and E-mail): DHS SWO, FEMA Ops Center, and NICC Watch Officer. Notified (via E-mail): FEMA NWC and NuclearSSA.
|ENS 51061||9 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|
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 hours 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.
|ENS 50263||8 July 2014 13:25:00||10 CFR 50.72(a)(1)(i), Emergency Class Declaration||Unusual Event Due to Smoke Alarm Inside Containment|
Unusual Event declared at 0935 EDT on July 8, 2014 due to a single fire alarm in containment. ELA HU4. No abnormal condition or plant impact at this time. The plant remains stable at 100% power. A single smoke detector inside containment alarmed at 0925 EDT. There are no other indications of smoke or fire at this time. Adjacent smoke detectors are not in alarm. A containment entry team is being assembled to verify that there is no fire inside containment. The smoke detector alarm cleared at 1006 EDT. The licensee notified the NRC Resident Inspector. The licensee will make appropriate notifications to state and local government agencies. Notified DHS, FEMA, and NICC via email and phone. Notified FEMA NWC and Nuclear SSA via email.
The Unusual Event was terminated at 1328 EDT on 7/8/14. A containment entry was performed and no indications of a fire existed. The fire alarm was spurious and the detector has been disabled. There was no notification of other government agencies and there is no media /press release planned. The plant maintained stable operations at 100% power. The licensee notified the NRC Resident Inspector, the state of Ohio and local officials. Notified R3DO (Hills) NRR EO (McGinty), IRC MOC (Grant). Notified DHS, FEMA, and NICC via email and phone. Notified FEMA NWC and Nuclear SSA via email.
|ENS 47443||16 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|
At 0222 EST on November 16, 2011, an ALERT was declared due to an electrical fire in the auxiliary building which houses safety related equipment. The apparent cause of the fire was due to an unknown source of water leaking on a breaker, thus causing an arc. The electrical fire is out. The plant was at 0% power and will remain shutdown in Mode 5. There was no impact on core cooling, or emergency power supplies. The licensee has notified the NRC Resident Inspector and state and local agencies.
At 0443 EST on November 16, 2011, Davis Besse, Unit 1 exited their ALERT. The electrical short affected the Control Room Emergency Ventilation Fan #1 Damper. The licensee has notified the NRC Resident Inspector. Notified R3DO (Hills) and Canada Nuclear Safety Commission (Jim Sandlef).
|Control Room Emergency Ventilation|
|ENS 46551||19 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|
An electrical fire and explosions were reported near the Containment Access Facility construction area. An Unusual Event was declared based on HU4. Temporary electrical power at service disconnect DSLM3-3 was isolated. The fire was out at 0243 EST. The fire was extinguished using dry chemical. The fire was reported at 0232 EST on 1/19/11. The cause of the fire has not been determined at this time. The fire and explosions were initially reported by site security personnel. The licensee declared the NOUE at 0243 EST based on criteria HU4. The licensee initially called for offsite assistance in putting out the fire, however, the fire was extinguished by plant personnel and the offsite assistance was turned back. The licensee posted a reflash watch. The fire reportedly involved temporary cables and possibly a transformer supplying power to the construction area which is located inside the protected area outside the auxiliary building. The licensee notified the NRC Resident Inspector.
The licensee terminated the Notification of Unusual Event at 0358 EST. No additional information is available at this time. Notified R3DO (Bloomer), NRR EO (Skeen), IRD (Gott), DHS (Stringfield), and FEMA (Casto).
|ENS 45162||25 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||A transitory ALERT (condition was determined to have existed) based on Emergency Action Level 7.D.2 - 'Onsite Explosion Affecting Plant Operation'. At time 0049 on 06/25/09 a catastrophic failure-explosion of the Constant Current Potential Device (CCPD) on 'J' Bus near Air Circuit Breaker (ACB) 34563 resulted in a loss of switchyard 345 KV Bus 'J'. This event de-energized Startup Transformer 01 which is a tie from offsite sources to the Unit 13.8 KV Busses. The unit entered (Technical Specification) LCO 3.8.1, Condition A (due to the loss of one offsite power source). The Unit remains stable and in operation at 100% RTP (reactor thermal power). A problem solving decision making team is working on (the) troubleshooting/repair/restoration activities. This event did not impact any plant safety systems or result in any release of radioactive material. Failure of the CCPD caused automatic opening of the breakers on both sides of the 'J' bus which was configured as part of a switchyard ring bus at the time of the event. This resulted in the loss of one of the offsite power ties. However, startup Transformer 02 is still energized from offsite power and remains available for plant operations. Other than the de-energized startup transformer, onsite electrical configurations are normal including availability of emergency diesel generators. The licensee is in a 72 hour LCO per Tech Spec 3.8.1, Condition A, to restore the lost offsite power source. The licensee is inspecting the switchyard for collateral damage to other equipment from the failure of the CCPD. The licensee believes the CCPD failure is likely a result of equipment failure and not the result of any equipment tampering. The licensee stated that initially, the severity of the CCPD failure was not recognized because of the night time conditions and minimal lighting in the area. After daylight examination of the location of the event, it was determined that the failure of the CCPD should have been classified as an explosion affecting plant operation under EAL 7.D.2. Consequently, the licensee made the after-the-fact declaration. Licensee has notified the NRC Resident Inspector, and will be notifying State and local authorities.||Emergency Diesel Generator|
|ENS 40070||14 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.|
All systems operated as expected. Decay Heat pumps are available if needed. NRC Resident Inspector was notified of this event by the licensee.
The plant exited the NOUE at 1940 on 08/15/03. The grid is stable, the plant is on off site power and the emergency diesels are in standby. Notified FEMA (Steindurf), Reg 3 RDO (S. Burgess) and EO (S. Richards)