Semantic search
| Entered date | Event description | |
|---|---|---|
| ENS 51950 | 23 May 2016 17:02:00 | On May 23, 2016, at 1009 EDT, while personnel were performing turbine testing with Unit 2 offline for planned maintenance, an event resulted in the actuation of containment isolation valves in more than one system. In response to this unexpected signal, 2B21F016 (Steam Line Drain Line Inboard Isolation Valve), 2B21F019 (Steam Line Drain Line Outboard Isolation Valve), and 2B31F019 (Reactor Water Sample Inboard Isolation Valve) went closed, all of which are primary containment isolation valves actuated by Group 1 Isolation. The Group 1 Isolation signal initiated based on low condenser vacuum during the turbine testing procedure, a valid condition that was expected to have been bypassed in the logic during the performance of this procedure. Human performance is believed to be the cause of these systems having actuated in a way that was not part of the planned evolution. Although the Unit was shut down when this signal was received, and primary containment isolation was not required to mitigate the consequences of an event, this Isolation signal has been determined to have been valid due to the initiation in response to actual plant conditions or parameters which satisfy the requirements for initiation of the system. The event is reportable as required by 10 CFR 50.72(b)(3)(iv)(A)(2): (A) Any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B) of this section except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation. (2) General containment isolation signals affecting containment isolation valves in more than one system or multiple main steam Isolation valves (MSIVs). The licensee has notified the NRC Resident Inspector. |
| ENS 50080 | 1 May 2014 22:33:00 | While investigating a Unit 1 high pressure coolant injection (HPCI) room instrument sump level high alarm, condensation was observed dripping out around the HPCI turbine shaft gland seals. A steady stream of water was also observed coming out of the governor end gland seal along with a slight leak coming from the coupling end. Observation revealed that leakage through the 'closed' steam admission valve (1E41-F001) was apparently resulting in water accumulation in the HPCI turbine. A blown fuse that prevented the associated HPCI exhaust drain pot from draining in conjunction with the leakage by the steam admission valve was determined to be sufficient to impact HPCI operability. Required actions were taken in accordance with the Technical Specifications. Efforts are underway to determine the actions needed to restore the HPCI system to operable status. The licensee has notified the NRC Resident Inspector.
HPCI has been restored to an Operable but degraded nonconforming condition. Fuses replaced and automatic functions restored. Leakage confirmed to not be excessive for this condition. Compensatory actions established. Restoration time 2345 EDT 5/1/14. The licensee will notify the NRC Resident Inspector. Notified R2DO (Ayers). |
| ENS 47065 | 16 July 2011 22:40:00 | The Technical Support Center ventilation system was found to be non-functional on 7/16/2011 at 1830 EDT. The time period that the Technical Support Center ventilation system was non-functional exceeded the 30 minute time limit that is delineated in the Technical Requirements Manual T3.10.1. This event is reportable per 10CFR50.72(b)(3)(xiii) as described in NUREG-1022, rev. 2 since this adversely affects an emergency response facility. Also, this 8 hour notification is made in accordance with Technical Requirements Manual T3.10.1.B.2 The alternate Technical Support Center facility was functional immediately and remains functional. Per the licensee, the Technical Support Center ventilation system remains out-of-service. The cause was due to a loss of refrigerant in the system. Repairs are currently underway. The licensee notified the NRC Resident Inspector. |