Wednesday, September 16, 2015

Hey Palisades, Haven't Heard From You For A Long Time

AUTOMATIC REACTOR TRIP DUE TO TURBINE TRIP

"At 0117 [EDT] on 9/16/2015 a reactor trip occurred (4-hr non-emergency). The plant was at approximately 85% power performing a coastdown in preparation for a refueling outage when a Digital Electro-Hydraulic (DEH) alarm was received in the control room. Shortly following receipt of the alarm the turbine tripped. This resulted in an RPS actuation and a reactor trip on Loss of Load. The crew entered EOP-1 Standard Post Trip Actions and completed all required actions. The crew subsequently entered EOP-2 Reactor Trip Recovery.

"All full-length control rods inserted fully. Auxiliary Feedwater System actuated in response to low steam generator water levels (8-hr non-emergency). Steam generator water levels are in progress of being returned to normal operating levels. No known primary to secondary leakage. Atmospheric Steam Dump Valves lifted after the trip and subsequently reseated.

"The plant is currently stable in Mode 3 at NOP/NOT being maintained by the Turbine Bypass Valve.

"Initial investigation into the cause of the turbine trip appears to be from a DEH power supply failure.

"The NRC Resident Inspector was notified of the reactor trip at 0139 on 9/16/2015."

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