Temelín nuclear plant in Czechia unexpectedly disconnected its second unit overnight due to turbine vibration

The Temelín nuclear power plant unexpectedly disconnected its second unit for several hours overnight. The cause was turbine vibration. By 12:00, the reactor was operating at approximately 70 percent capacity. It is expected to reach full capacity later today. Plant spokesperson Marek Sviták told the Czech News Agency.

„Overnight, reactor output was reduced to approximately 40 percent. This was a targeted preventive measure to protect the turbine from increased vibration, during which the generator was disconnected from the transmission grid for several hours. After carrying out inspections, we reconnected the unit to the transmission grid this morning,“ the spokesperson said.

He added that the disconnection did not affect electricity supplies.

Sviták said that turbine vibration is a feature of the operation of all rotating machinery. Two weeks ago, energy workers at Temelín unexpectedly disconnected the first unit from the transmission grid for a few hours. The reason was an inspection and repair of a water valve in the circuit between the condensers and cooling towers in the plant’s non-nuclear section. The Temelín power plant has generated 8.7 TWh of electricity so far this year, compared with 16 TWh for all of last year. The plant will invest 4.1 billion crowns in modernisation this year.