Semantic search
Jump to navigation
Jump to search
| Entered date | Event description | |
|---|---|---|
| ENS 56165 | 15 October 2022 15:46:00 | The following information was provided by the licensee via email: On 10/15/2022 at 1159 (EDT), during the Catawba Nuclear Station Unit 2 refueling outage, it was determined that the results of a planned surface examination Liquid Penetrant test (PT) performed on a previous overlay repair on nozzle number 74 of the reactor vessel closure head (RVCH) did not meet applicable acceptance standards. The examination was being performed to meet the requirements of Relief Request RA-21-0144, 'Proposed Alternative to Use Reactor Vessel Head Penetration Embedded Flaw Repair for Life of Plant'. The penetration required repairs for the discovered indications. The repairs have been completed in accordance with the ASME Code of Record prior to returning the vessel head to service. This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The original indication that led to the overlay repair was discovered in April 2021, during ultrasonic testing and reported to the NRC and assigned EN55201. |
| ENS 54523 | 12 February 2020 21:51:00 | At 1800 EST, on February 12, 2020, with Unit 1 in Mode 1 at 100 percent power, the reactor automatically tripped due to a turbine trip. The trip was not complex, with all systems responding normally post trip. Because of the reactor trip, the Auxiliary Feedwater (AFW) System actuated as expected due to on ATWS Mitigation System Actuation Circuitry (AMSAC) signal. The AFW pumps started as designed when the valid system actuation was received. Operations responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the condenser steam dump valves. Due to the Reactor Protection System (RPS) actuation while critical, this event is being reported as an 4-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported as an 8-hour non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the AFW system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The site remains in a normal electrical lineup. The cause of the turbine trip is under investigation. |
| ENS 54307 | 2 October 2019 11:50:00 | On October 2, 2019, at 0415 EDT, with Unit 2 in Mode 5 at 0 percent power, an actuation of the Unit 2 containment spray system occurred during valve strokes of the 2A train containment spray header isolations while the 2B train containment spray pump was in recirculation. The reason for the containment spray actuation was due to a conflicting procedural alignment with the 2B containment spray recirculation procedure. The containment spray system does not have an automatic function, and only receives manual actuation. The Unit 2 containment spray actuation was secured at 0416. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the containment spray system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 54286 | 19 September 2019 14:08:00 | 10 CFR 50.72(b)(3)(v)(A, B, and D) - Event or Condition that Could Have Prevented the Fulfillment of a Safety Function Unit 2 Component Cooling water system inoperable. On July 6, 2019, from 0156 to 1545 (EDT), it was determined that both trains of the unit 2 component cooling water system were simultaneously inoperable; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). The affected safety function was restored on July 6, 2019, at 1545 (EDT) when the 2B component cooling train was restored to operable. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. At the time of the event no other safety related systems were inoperable. The event had no impact on Unit 1. |
| ENS 53271 | 19 March 2018 10:49:00 | Automatic actuation of the 2B CA (Auxiliary Feedwater) System. At 0329 (EDT on) 03-19-18, with Unit 2 in Mode 5, an actuation of the 2B CA (Auxiliary Feedwater) system occurred during maintenance associated with the 2B Main Feedwater Pump. The cause of the CA (Auxiliary Feedwater) system automatic start was an unanticipated reset and subsequent trip signal of the 2B Main Feedwater pump during maintenance activities. The 2B CA Pump/Train automatically started as designed when the 'Loss of Both Main Feedwater Pumps' signal was received. The system operated as required. This event is being reported in accordance with 10CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the CA System. There was no impact on the health and safety of the public or plant personnel. The NRC Resident has been notified. |