12. 10. 2023

Dukovany to shut down unit 4, to use NG fuel for first time

Dukovany, South Moravia, Oct 12 (CTK) - Nuclear power plant Dukovany nuke will use for the first time new-generation fuel that is more efficient, planning to load it into the reactor of unit 4, whose planned shutdown starts on Friday and is to last until the year's end, plant spokesman Jiri Bezdek told CTK today.

Besides fuel replacement, unit 4 is scheduled to undergo regular checks and modernisation. Technicians will remove all 349 fuel assemblies from the reactor. Once the servicing is complete and all checks have been carried out, they will return some of the used fuel and 78 fresh fuel assemblies to the reactor. For the first time, fuel PK3+ will be used, which is designed to make the use of uranium in the fuel more efficient, Bezdek said.

"The new fuel type is one of the results of our efforts to continuously improve the safety, reliability and efficiency of operation of both our nuclear power plants," said Bohdan Zronek, energy company CEZ's board member and nuclear power division head.

CEZ, the operator of both Czech nuclear power plants, Dukovany and Temelin, has managed to diversify its fuel suppliers. It is also expanding its storage capacity so that the plant can have fuel in stock for almost five years, Zronek noted.

So far, nuclear fuel has been supplied to Dukovany by Russian company TVEL. This year, CEZ has agreed on supplies with US company Westinghouse.

Unit 4 will be shut down after more than 440 days of operation. Technicians will start reducing its output at noon on Friday, and the same day the unit will stop supplying electricity to the grid.

"We are facing the last outage of this year," Dukovany head Roman Havlin said.

Over 14,600 work tasks will be carried out during the outage. According to CEZ, the most demanding will include the revision of two backup diesel generators, leak checking and cleaning of steam generators and overhaul of two main circulation pumps. The inspections will also cover the steam turbines.

The Dukovany units were commissioned between 1985 and 1987. CEZ says it would like to keep them in operation for at least 60 years.

Last year, Dukovany delivered 14.7 terawatt hours (TWh) of electricity, its fifth highest annual output. Since the beginning of this year, it has generated nearly 11.5 TWh of electricity.

CEZ expects final bids from bidders for the construction of a new unit at Dukovany by the end of October.