Loss of Power Resulted in a Valid Isolation Signal
At 0937 EDT on 6/27/19, Susquehanna Unit 2 had a control power fuse fail that caused a loss of power to one of two power distribution systems of the Reactor Protection System. This loss of power resulted in a valid isolation signal and actuation of the Primary Containment Isolation System that affected multiple systems, and is reportable per 10 CFR 50.72(b)(3)(iv)(A).
The situation has been resolved and the plant is currently using an alternate power source. Offsite power and the Emergency Diesel Generators are still available.
NRC Inspection of Ti 2515/194, Inspection of the Licensee'S Implementation of Industry Initiative Associated with the OPC Design Vulnerabilities in Electric Power Systems (NRC Bulletin 2012-01); IR05000254(265)/2019012