Czech Temelín unit 2 back in operation, technicians resume generation after outage

Technicians reconnected Temelín unit 2 to the grid today before 17:00 following an unplanned outage. The turbine generator set was disconnected from the grid on Wednesday due to a fault in part of the control system for the non-nuclear section of the plant. Marek Sviták, spokesperson for the Temelín Nuclear Power Plant, told ČTK.

"Technicians inspected the system and subsequently replaced the affected electronic card in the control cabinet. The operating staff are currently increasing reactor output. We expect to reach full output overnight," Sviták said.

Unit 1 is generating electricity at 100 percent.

Temelín last unplannedly reduced the output of unit 2 in mid-January this year. Output was lowered to around 40 percent. The reason was the replacement of a bearing in a circulation pump in the plant's non-nuclear section, which cannot be carried out while operating at full output. The plant had previously unplannedly disconnected unit 2 for several hours, for example in July 2024, first to repair a water valve and then due to turbine vibrations.

The planned outage of Temelín unit 2 ran from February to April this year. During the outage, technicians replaced part of the fuel assemblies and inspected the safety systems and turbines. The utility also completed the transition to a longer fuel cycle. Temelín unit 1 is scheduled for a planned outage from October.

ČEZ will invest 3.8 billion crowns in the modernisation of the Temelín Nuclear Power Plant this year. This is 700 million Kč more than last year.