Zaporizhia NPP restarts 3rd reactor unit shut down by automatic protection system week ago

The Zaporizhia nuclear power plant started to bring its reactor unit up to a minimum controllable power level at 04:27 Kyiv time on Friday, state-run Energoatom nuclear power company said.

The reactor unit will be connected to the power grid before 23:00 Kyiv time on the same day in accordance with the maintenance schedule, Interfax-Ukraine reported.

The automatic protection system disconnected the third reactor unit of the Zaporizhia NPP at 19:24 Kyiv time on November 28 due to damage caused to the coil connecting the house load transformer and unit transformer breakers. The automatic protection system responded in strict compliance with the protocol.

"The cold shutdown of the reactor proceeded normally, without radiological consequences," the NPP administration emphasized.

The unplanned disconnection of the third reactor unit of the Zaporizhia nuclear power plant has been tentatively assessed as a "below scale/level 0" event by the INES International Nuclear and Radiological Event Scale. This event has no safety implications.

The Zaporizhia NPP is the largest nuclear power plant in Europe by its rated capacity. Its six VVER-1000 reactor units were built by the Soviet project V-320. The first reactor unit was started up in December 1984 and the sixth in October 1995.

Energoatom is the operator of all four nuclear power plants currently working in Ukraine: the Zaporizhia, Yuzhnoukrainsk, Rivne and Khmelnytsky power plants with 15 pressurized light water reactors and a total rated capacity of 13.835 gigawatts.