Planned outage of Dukovany's second unit in Czechia ends after two months

The planned outage of the second unit at the Dukovany Nuclear Power Plant, involving the replacement of part of its fuel, maintenance and equipment inspections, has ended. The unit stopped supplying electricity to the grid on 29 August. Engineers restored power generation from both turbine-generator sets on Monday at 23:13. Plant spokesperson Jiří Bezděk told ČTK today. All four Dukovany units are now in operation. The plant is expected to reach full capacity in the coming days.

"Before the unit can reach full capacity, engineers still have a series of standard tests and checks to carry out," the spokesperson said.

Operators restarted the controlled nuclear fission reaction in the second unit's reactor last Saturday evening. They then increased its output and carried out the required equipment checks and tests. The unit began reconnecting to the transmission grid on Monday afternoon.

In addition to replacing one-fifth of the reactor's fuel assemblies with fresh ones, engineers carried out a large number of work tasks in the unit. Among the most significant were cable replacements, the refurbishment of section switchboards and the modernisation of the control and safety system of one of the three backup diesel generators. According to ČEZ, engineers completed the work in the unit several days ahead of schedule.

The next outage at Dukovany is scheduled for the first unit in mid-December. "We always try to schedule outages at the largest Czech power plants for periods of lower demand. The Christmas holidays are one such period," said Bohdan Zronek, a member of ČEZ's board of directors and director of its nuclear energy division.

Czechia has six nuclear units at two power plants. Last year, Dukovany supplied 14.7 terawatt-hours (TWh) of electricity to the transmission grid, and it has supplied 12.1 TWh so far this year. The Temelín Nuclear Power Plant generated 15 TWh of electricity last year.

The Dukovany Nuclear Power Plant currently has four units, which were commissioned between 1985 and 1987. South Korea's KHNP won the contract to build two additional units. In June, it signed an agreement to build the units with Elektrárna Dukovany II, the company responsible for the project as the investor. Geological surveys for the units began in August.