Semantic search
| Entered date | Event description | |
|---|---|---|
| ENS 48980 | 29 April 2013 08:41:00 | At 0900 EDT on Monday, April 29, 2013, the Cook Nuclear Plant (CNP) Technical Support Center (TSC) air conditioning and charcoal filtration systems will be removed from service for scheduled maintenance. Under certain accident conditions the TSC may become unavailable due to the inability of the air conditioning and charcoal filtration systems to maintain a habitable atmosphere. Compensatory measures exist to relocate TSC personnel to the unaffected unit's control room, if necessary. TSC ventilation system maintenance and post maintenance testing is scheduled to be completed by 1200 EDT on Thursday, May 2, 2013. The licensee has notified the NRC Resident Inspector. This notification is being made in accordance with 10 CFR 50.72 (b)(3)(xiii) due to the loss of an emergency response facility.
Due to scheduling issues, the restoration of the Technical Support Center (TSC) air conditioning and charcoal filtration systems has been delayed. The TSC ventilation systems are expected to be returned to service by 0000 EDT on Friday, May 3, 2013. The licensee has notified the NRC Resident Inspector. Notified R3DO (Duncan).
The restoration of the Technical Support Center (TSC) air conditioning and charcoal filtration systems has been delayed but is in progress. The TSC ventilation systems are expected to be returned to service by 0600 EDT on Friday, May 3 2013. The licensee will notify the NRC Resident Inspector. Notified R3DO (Duncan).
The Technical Support Center (TSC) air conditioning and charcoal filtration systems were restored at 0818 EDT. The TSC is fully functional. The NRC Resident Inspector has been notified. Notified the R3DO (Duncan). |
| ENS 48964 | 24 April 2013 17:15:00 | On 4/24/13 at 1411 EDT, a fault occurred on the Unit 1 101 CD Reserve Auxiliary Transformer causing the 12 CD 34kV Reserve Feed Breaker to open resulting in a loss of Train A Reserve Feed to Unit 1 and Unit 2. The cause of the fault is still under investigation. Unit 2 remains stable in 100% power. Unit 2 entered LCO 3.8.1, AC Source - Operating, Condition A, one required offsite circuit inoperable Restore Unit 2 reserve feed to operable status within 72 hours. Unit 1 is currently in a refueling outage and offline. Unit 1 CD Emergency Diesel Generator (EDG) automatically started and loaded as expected. North Spent Fuel Pit Cooling Train lost power due to a load shed, which resulted in a 2 degree Fahrenheit rise in the Spent Fuel Pool Temperature. The North Spent Fuel Pit Cooling Pump was restarted on 1 CD EDG at 1447 EDT. South Spent Fuel Pool Cooling Train remained in-service the entire time. The licensee has notified the NRC Resident Inspector. |
| ENS 48945 | 19 April 2013 12:30:00 | On 4/18/13 at 2312 EDT, Emergency Siren 955 inadvertently actuated for approximately 5 minutes. The cause of the actuation is under investigation but believed to be due to rain water intrusion. The siren stopped on its own, and was subsequently disconnected by the siren vendor to prevent further erroneous actuation. The siren remains out service and is the only siren out of service within the 10 mile Emergency Planning Zone (EPZ). There are a total of 70 sirens. The siren is located in a state park not currently inhabited by campers; due to the siren location and time of activation the impact on the surrounding population was minimal. The event was therefore determined to not be reportable. A subsequent review of the event, considering communications made between Cook Nuclear Plant and the Berrien County 911 Dispatch Center, as well as recent industry operating experience of similar events, was performed; its conclusion was to conservatively make a report under 10 CFR 50.72(b)(2)(xi). The licensee has notified the NRC Resident Inspector. |
| ENS 48922 | 14 April 2013 13:47:00 | At 1400 EDT on Sunday, April 14, 2013, the Cook Nuclear Plant (CNP) Technical Support Center (TSC) air conditioning and charcoal filtration systems will be removed from service for scheduled maintenance. Under certain accident conditions, the TSC may become unavailable due to the inability of the air conditioning and charcoal filtration systems to maintain a habitable atmosphere. Compensatory measures exist to relocate TSC personnel to the unaffected unit's control room if necessary. TSC ventilation system maintenance and post maintenance testing is scheduled to be completed by 1400 EDT on Wednesday, April 17, 2013. The licensee has notified the NRC Resident Inspector. This notification is being made in accordance with 10 CFR 50.72 (b)(3)(xiii) due to the loss of an emergency response facility.
The Technical Support Center (TSC) air conditioning and filtration systems have been returned to service following maintenance. The TSC is fully functional. The NRC Resident Inspector has been notified. Notified R3DO (Orth). |
| ENS 47247 | 7 September 2011 12:14:00 | On Sept 7, 2011, at 0854, DC Cook Unit 1 reactor automatically tripped due to a trip of the main turbine. The cause of the main turbine trip is still under investigation. This event is reportable under 10 CFR 50.72(b)(2)(iv)(B), Reactor Protection System (RPS) actuation, as a four (4) hour report, and under 10 CFR 50.72(b)(3)(iv)(A), specified system actuation of the Auxiliary Feedwater System, as an eight (8) hour report. The DC Cook Sr. Resident NRC Inspector has been notified. 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 steam dumps to the main condenser. Preliminary evaluation indicates all plant systems functioned normally following the reactor trip. DC Cook Unit 1 remains stable in Mode 3 while conducting the post trip review. |