Unit 2 of the Talen Energy (NYSE:TLN) Susquehanna nuclear power plant in Luzerne County, Pennsylvania was forced offline in the early morning hours of May 13 apparently because of a problem with “an essential motor control center.”
That’s the assessment offer in an event report filed with the Nuclear Regulatory Commission (NRC).
“At approximately 0110 hours [EDT] on May 13, 2016, Susquehanna Steam Electric Station Unit Two reactor was manually scrammed by plant operators due to a sustained loss of AC power to essential plant loads,” according to the report filed with NRC.
“The power loss also tripped Reactor Building HVAC [heating, ventilation, and air conditioning], causing a loss of secondary containment differential pressure resulting in a loss of safety function,” according to the event report filed with NRC.
In its own news release, Talen reported that the shutdown followed an electrical fault in one of the unit’s 480-volt electrical distribution centers.
“The fault interrupted power supply to some of the systems we use to operate the unit,” said Jon Franke, site vice president. “Our operators determined the need to bring the unit off-line, and completed the shutdown safely, as designed, using established plant procedures and reflecting the conditions they experienced due to the electrical fault.”
Franke said plant workers are investigating the cause of the electrical issue and will determine the necessary repairs. When repairs are completed, operators will begin the process of returning the unit to service.
Unit 2 had been in continuous operation for 355 days since returning to service from its last scheduled refueling and maintenance outage in May 2015. Susquehanna 1 continued to run at 100% power.
Both Susquehanna units are boiling water reactors (BWRs) commissioned in the 1980s. Each can generate roughly 1,200 MW.
The Susquehanna plant, located about seven miles north of Berwick, is jointly owned by Talen’s Susquehanna Nuclear, LLC, and Allegheny Electric Cooperative, and is operated by Susquehanna Nuclear.