Czech nuke plants to replace fuel less often, raise output

Prague, Sept 21 (CTK) - Czechia's nuclear power plants will replace fuel less often, which energy group CEZ expects will raise total electricity output by almost two terawatt hours (TWh) per year by 2030, CEZ board member and nuclear energy division head Bohdan Zronek told CTK today.

The interval between shutdowns will be extended from the current 12 months to 18 months at the Temelin plant and to 16 months at Dukovany, and the transition to extended fuel cycles will be gradual, to be fully operational from 2025, Zronek said.

The difference between the Temelin and Dukovany future cycles stems from technical differences between the plants, he noted.

In 2022, electricity consumption in the Czech Republic was 60.4 TWh, and the planned increase in production thus corresponds to up to 3 percent of Czech consumption.

With all safety parameters carefully verified and all security standards maintained, the extension of the intervals has not required any special investments in equipment and is mainly a change in the working procedure, Zronek added.

The transition to a longer cycle between replacements has now begun at Temelin. Instead of the existing 42 fuel assemblies, 48 fresh fuel assemblies will now be brought to the reactor. In total, 163 fuel assemblies will be placed in the shut-down second reactor of the plant, including the unreplaced ones. The second unit will thus be in operation for about one month longer.

According to CEZ, the extension of the intervals should not change the length of shutdowns, and the replacement of a larger number of fuel assemblies will not affect their duration.

"Shutdowns will continue to last about two months," said Marek Svitak, spokesman for the Temelin plant.

Eighteen-month fuel cycles are now standard for most nuclear power plants abroad, CEZ said. In Czechia, the group has been working on the change since 2018, when preparations for the authorisation procedure began.

Last year, the Dukovany and Temelin nuclear power plants produced the largest amount of electricity to date, delivering a total of 31.02 TWh of electricity to the grid, which is almost 300,000 megawatt hours (MWh) more yr/yr.

In total, CEZ is investing about Kc6bn in Dukovany and Temelin this year, in view of the planned 60-year operation. In accordance with the investment and review plan, CEZ plans to operate the Dukovany plant until at least 2047, and Temelin for another 13 years after that.

hja/er/hel