Dukovany Unit 4 returns to grid after planned outage

Dukovany Unit 4 returns to grid after planned outage

Dukovany, South Moravia, June 26 (CTK) - The Dukovany nuclear power plant's Unit 4 was reconnected to the grid after ending its planned outage for fuel replacement, which began on April 17, and is expected to return to full capacity within a few days, energy group CEZ spokeswoman Jana Stepankova told CTK today.

During the outage, workers completed more than 21,000 maintenance tasks and carried out 60 major technical operations. "This outage involved an exceptionally extensive programme of inspections and investment work," plant director Roman Havlin said.

Operators restarted the controlled nuclear fission reaction in Unit 4's reactor on Wednesday morning. The first turbine generator was connected to the grid at 11:33 today and the second at 15:42 p.m. The unit's output is now being gradually increased while the required inspections and tests are carried out.

All six Czech nuclear power units are now in operation, four at Dukovany and two at Temelin. Unit 3 at Dukovany is scheduled to begin its planned outage in the second half of July, while Temelin plans to start the outage of Unit 1 in October.

According to CEZ, the completed outage was one of the most extensive ever carried out at Dukovany. Experts inspected the reactor pressure vessel's internal components, tested safety systems, cleaned another steam generator in cooperation with foreign specialists, and carried out construction work on the underground sections of the cooling towers. They also replaced 78 of the reactor's 349 fuel assemblies with fresh fuel.

Both Czech nuclear power plants have gradually switched to longer fuel cycles. Since 2024, Dukovany has operated on a standard 16-month fuel cycle, with its units running for 14 months between outages followed by a shutdown lasting more than a month. Temelin is set to complete its transition to an 18-month fuel cycle this year. According to CEZ, the move is intended to increase overall electricity generation, improve nuclear fuel utilisation and reduce wear on equipment by maintaining more stable operating conditions.

Temelin and Dukovany generated a combined 32.066 terawatt-hours (TWh) of electricity last year, including 14.68 TWh at Dukovany. So far this year, Dukovany has supplied 7.15 TWh of electricity.

Dukovany's four generating units were commissioned between 1985 and 1987. According to CEZ's current projections, they could remain in operation for up to 80 years from their commissioning dates, or until 2065-2067. South Korean company Hydro & Nuclear Power (KHNP) has been awarded the contract to build two additional units at the Dukovany site.

tam/er