8. 6. 2023

The Temelín Unit 1 produces electricity again. The planned outage lasted two months.

Today at 13 o´clock, Unit 1 of Temelín NPP started to produce electricity again. Operators have connected it to the transmission system after replacing a quarter of the fuel assemblies. Power engineers also checked the safety systems or the turbine. The containment building around the reactor also passed the leak test. They managed 18,000 activities during the shutdown, including 78 investment actions. Together with the Dukovany power plant, all six nuclear units are currently in operation. Unit 1 of the Dukovany Nuclear Power Plant is now planned to be shut down for inspection and refuelling.

Temelín's Unit 1 began to deliver electricity into the transmission grid again at 50 % of the reactor-rated power. It should reach full performance within a few days. 

“It is associated with a series of verifications to confirm that the unit is ready for safe and reliable operation,"

said Jan Kruml, Director of the Temelín Nuclear Power Plant.

The technicians are now looking forward to tests at eighty per cent of the reactor-rated power, which will mainly verify the uniform power distribution in the reactor. "We will also monitor other equipment, especially the turbine, where hundredths of millimetres are decisive during operation. The first days of operation will show us whether the settings will still need to be fine-tuned," added Jan Kruml.

During the outage, technicians exchanged 42 of the 163 fuel assemblies, checked safety systems, or carried out 78 investment actions. Including the external suppliers, around a thousand people were involved in the outage works.

"We plan and coordinate the outages of our six nuclear units so that there is minimal concurrence. From Temelín, the work is now moving smoothly to the outage of Unit 1 in Dukovany, which began at the end of last week,”

stated Bohdan Zronek, member of the Board of Directors of ČEZ and Director of the Nuclear Energy Division.

Another outage awaits Temelín in the second half of August. The technicians try to replace the fuel assemblies in the largest Czech Units in a period of lower consumption and higher production from renewable sources.


Since the beginning of the year, the Temelín power plant has produced 6.7 terawatt hours of electricity. Together with Dukovany, these sources produce the most significant amount of clean electricity and thus contribute significantly to ČEZ Group's emission-free production. Annually, approximately two tens of millions of tonnes of CO2 have not been released into the atmosphere thanks to nuclear power plants.