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| Entered date | Event description | |
|---|---|---|
| ENS 51624 | 28 December 2015 08:38:00 | This is to report the Salem Unit 2, 2C Safeguards Equipment Cabinet (SEC) actuation due to an invalid signal. This report is being made per paragraphs 10 CFR 50.73(a)(1) and 10 CFR 50.73(a)(2)(iv)(A) to address the invalid actuation of the 2C SEC on October 29, 2015, during performance of maintenance on the Solid State Protection System (SSPS). Plant conditions: Salem Unit 2 was in Mode 6 at the time of the invalid actuation. On October 29, 2015, at approximately 1112 (EDT) during performance of maintenance to replace slave relays in the SSPS output test panel 131, the maintenance technician inadvertently made contact with the relay plunger for the 2C SEC. This caused a signal to be sent to the 2C SEC which actuated the equipment associated with it. The 2C SEC train responded to the signal as required. The equipment associated with the 2C SEC that was not previously removed from service for outage related activities or already in service responded as required. As a result of the actuation, the 2C Emergency Diesel Generator (EDG) started but did not load (no undervoltage condition existed on the associated vital bus requiring loading), the Unit 2 Emergency Control Air Compressor (ECAC) started. The 22 Charging Pump (CVC) started, and the 22 Safety Injection Pump (SI) started (the Sl pump did not inject as it was isolated and in the process of being tagged out of service at the time of the invalid signal). The cause of the invalid actuation signal was a human performance error. The licensee notified the NRC Resident Inspector. |
| ENS 49699 | 7 January 2014 13:12:00 | At approximately 0745 on January 7, 2014, a review of maintenance activities performed on October 3, 2013 on Salem Unit 2, identified an instance in which a High Energy Line Break (HELB) barrier access door was not properly controlled during a Turbine Driven Auxiliary Feedwater Pump room maintenance activity. A HELB event occurring in a room with its barrier door open could adversely affect equipment in an adjacent room. The steam supply to the Turbine Driven Auxiliary Feedwater Pump was not isolated in support of the maintenance activities and the room HELB barrier door was not properly controlled during maintenance in the room. Consequently, a HELB event occurring in the Unit 2 Turbine Driven Auxiliary Feedwater Pump room with the impaired barrier door, could have rendered the Turbine Driven Auxiliary Feed water Pump and both of the Motor Driven Auxiliary Feedwater Pumps in the adjacent room inoperable. This event is being reported under the requirements of 10 CFR 50.72(b)(3)(ii)(B) as "the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety." An ENS notification is required if an unanalyzed condition occurred within 3 years of the date of discovery even if the event is not on-going at the time of discovery. The Licensee has notified the NRC Resident. The licensee also will notify the Lower Alloways Creek Township. |
| ENS 46337 | 17 October 2010 06:38:00 | On 10/17/10 at 0512 (EDT), Unit 2 experienced an (automatic) reactor trip due to 4 kV group bus under voltage. While restoring the voltage regulator to automatic, following a swap to manual at 0123 (EDT) on 10/17/10 while 500 kV line 5014 was being restored to service, the reactor tripped after placing the voltage regulator in automatic. The crew entered EOP (Emergency Operating Procedure) Trip 1, and then EOP Trip 2 as required. The plant was stabilized at no load conditions. All rods fully inserted on the trip, and all systems responded as designed with RCS (Reactor Coolant System) temperature being controlled via 21 RCP (Reactor Coolant Pump) and the steam dump system. 22, 23, and 24 RCP's tripped on group bus under voltage. The AFW (Auxiliary Feed Water) Pumps started in response to low steam generator levels. 23 AFW was subsequently tripped per procedure since 21 and 22 AFW pumps were in service feeding 21-24 steam generators. Salem Unit 2 is currently in Mode 3. RCS temperature is 547 degrees. RCS pressure is 2235 pounds. All Emergency Core Cooling Systems and Engineered Safety Function Systems are available. No personnel injuries occurred as a result of the trip. No radiological release is in progress due to this event. At 0123 EDT, following the restoration of a 500 kV line, perturbation in the line caused an over current condition which shifted the voltage regulator to manual. After engineering's recommendation, the voltage regulator was placed in automatic shortly prior to the reactor trip. The plant is in a normal shutdown electrical lineup. There was no impact on Salem Unit 1 as a result of this event. The licensee has notified the NRC Resident Inspector.
Notified by the licensee that the AFW Pumps started on loss of Steam Generator Feed Pumps which had tripped on low suction pressure. The licensee has notified the NRC Resident Inspector. |