ČEZ to disconnect Temelín Unit 1 for outage of 19,000 tasks
66 fuel assemblies will be replaced and about 1,000 people, half from contractor firms, will work on the unit during the roughly two-month outage.
Key facts
- Unit 1 comes off the transmission grid on the evening of October 16
- Inspections cover the reactor pressure vessel, turbine and generator, including rotor removal
- Four storage casks to be moved into the spent fuel storage facility
- Unit 1 completes the shift to an 18-month fuel cycle at the end of November
- ČEZ targets 32 TWh a year on average from its nuclear units, per Zronek
ČEZ will disconnect the Temelín Unit 1 generator from the transmission grid on the evening of Friday, October 16, starting a scheduled outage, the company said. The reactor will be running at approximately one-third of its capacity when the generator comes off the grid. ČEZ has tentatively reserved two months for the work and plans more than 19,000 tasks at the unit. Temelín has two outages scheduled this year.
Crews will replace 66 fuel assemblies. They will inspect the reactor pressure vessel, one of the four steam generators and one reactor coolant pump, and move four storage casks into the spent fuel storage facility. In the secondary circuit, the turbine and generator will be inspected, including pulling out the generator rotor.
Seventy investment projects are in the plan
Petr Měšťan said the plant has 70 investment projects planned, among them replacing the fire water tank and continuing the transition to a new control system. The integrity of the containment building surrounding the reactor will be verified at the end of the outage. Approximately 1,000 people will take part in the outage work, half of them employees of contractor firms.
Fuel cycle stretches to 18 months
Temelín will complete its transition to an 18-month fuel cycle this year: sixteen months of operation and approximately two months of outage. Unit 2 already runs on that schedule, and Unit 1 will move to the extended cycle at the end of November. At Dukovany, a 16-month fuel cycle has been standard since 2024, with units operating 15 months between outages and outages lasting more than a month.
"All of our nuclear units have transitioned, or are currently transitioning, to longer fuel cycles," said Bohdan Zronek, a member of the ČEZ Board of Directors and director of the Nuclear Energy Division. Temelín can therefore expect alternating years with two outages and one, he said, which will affect annual production; the long-term goal remains an average of 32 terawatt-hours per year.
