A planned outage of the second unit at the Czech Dukovany nuclear plant starts today and will last until August

A planned outage of the second unit at the Dukovany Nuclear Power Plant begins today, involving maintenance, equipment inspections and the replacement of part of the fuel. It will last until August. Operators will begin reducing the reactor’s output at noon, and it will stop supplying electricity to the grid in the evening. Jiří Bezděk, a spokesperson for the plant, told the Czech News Agency. The other three Dukovany units are in operation.

„We have a range of standard and routine work ahead of us, as well as 61 technical and investment projects related to ensuring safe and efficient operation at least until 2047,“ plant director Roman Havlín said of the second-unit outage.

ČEZ expects the outage to end during August. The exact date will depend mainly on the results of inspections and tests, the spokesperson said. The first Dukovany unit will be taken offline after the second unit’s outage.

„This outage, and partly the next one at Dukovany, is scheduled for the summer. That is demanding for employees and suppliers, but makes sense from a production perspective,“ said Bohdan Zronek, a member of the ČEZ board and head of its nuclear energy division.

He added that electricity consumption is usually somewhat lower in summer, while photovoltaic plants generate a lot of power.

The second Dukovany unit is beginning its 37th outage involving fuel replacement. Since it entered service in 1986, the unit has generated 127 terawatt-hours (TWh) of electricity, equivalent to two years of Czechia’s consumption, according to ČEZ.

Over the coming weeks, energy workers will carry out more than 18,000 work tasks on the second unit. These include checking the tightness of heat-transfer tubes and cleaning steam generators, a general overhaul of two of the six main circulation pumps, and the ten-year general inspection of diesel generator No. 4.

As with the third Dukovany unit in April, operators are expected to raise the second unit’s output to 511 megawatts (MW) after the outage, up from its previous 500 MW.

Czechia has six nuclear units at two power plants. The Dukovany plant generated 14.3 TWh of electricity last year. In 2023, the Temelín Nuclear Power Plant exceeded 16 TWh of generation for the second year in a row.

ČEZ is preparing to build a new nuclear power source at Dukovany. At the end of April, it received bids from France’s EDF and South Korea’s KHNP to build up to four reactors in Czechia. The government will select the winner in the summer and is also expected to decide how many units should be built in the future. The state currently expects the first of them to begin operating at Dukovany in 2036.