Mochovce 3 successfully completes commissioning process

17 October 2023

Slovenské elektrárne has announced that the new Mochovce 3 unit has successfully completed a 144-hour demonstration run at full reactor power - and been welcomed into their nuclear fleet.

Mochovce 3 and 4 will each produce 13% of Slovakia's electricity needs (Image: Slovenské elektrárne)

The commissioning process for the new unit has lasted for more than a year with hundreds of safety tests taking place and the power has been gradually increased. The final step in the process was to run non-stop for six days and nights at full power to show it was ready for safe operation.

Branislav Strýček, Chairman of the Board and CEO of Slovenské elektrárne, said: "The third unit is an important pillar of our efforts to ensure a stable and safe supply of electricity for Slovakia ... and help us fulfil our obligations in the field of climate change. Our goal is to continue investing in the technologies of the future in order to ensure a sustainable future for people in Slovakia and Europe."

Juraj Krasňanský, director of completion and commissioning of Mochovce 3 and 4, said that it was the first new nuclear block launched in Slovakia for more than 20 years. He said that some of those involved had experienced putting units into operation during the days of the former Czechoslovakia: "It is important that we pass the baton to the next generations and maintain the knowledge necessary for the energy security of our country."

Martin Mráz, director of Mochovce, said: "With the completion of unit 3 commissioning, we welcome a new unit to our nuclear fleet. The power plant successfully passed demanding tests, including disconnection from the power system at full power ... we are already preparing for its first planned shutdown and normal operational activities."

The scale, and length, of the testing process is designed to prioritise safety at all stages and reflects the size of the new plant - with 1400 rooms, 100,000 bits of equipment, 5500 kilometres of cables and 175 kilometres of pipes.

Construction of the first two VVER-440 units at the four-unit Mochovce plant started in 1982. Work began on units 3 and 4 in 1986, but stalled in 1992. The first two reactors were completed and came into operation in 1998 and 1999, respectively, with a project to complete units 3 and 4 beginning ten years later. Unit 4's schedule has been to follow about one or two years behind unit 3. Each of the units will be able to provide 13% of Slovakia's electricity needs when operating at full capacity.

Slovenské elektrárne noted that since being connected to the grid on 31 January this year, Mochovce 3 has, during tests, supplied 1.2 million megawatt hours, sufficient to cover the average annual consumption of about 500,000 Slovak households.

Researched and written by World Nuclear News