First megawatts from Mochovce 3- Starting up of new nuclear unit is a major milestone for Europe

Miroslav Tokár, Director of Nuclear Power Plants Division (CNO), Slovenské elektrárne, a.s.

There have been only four units under construction over the past decade in the EU. Olkiluoto 3 was synchronised to the grid last year, Mochovce 3 this year, and Flamanville 3 and Mochovce 4 will join their siblings soon. Due to constantly rising safety requirements and increasingly stringent regulation, it is much more difficult to commission and license new nuclear units in Europe today than it was in the late nineties, when Mochovce 1 and 2 were connected to the grid.

First, a few facts.

Slovenské elektrárne, the company operating both the Bohunice and Mochovce Nuclear Power Plants (NPPs), received a permit from the Slovak Nuclear Regulatory Authority on 25 August 2022 and the commissioning of Mochovce 3 started on 9 September. The first controlled nuclear fission reaction date was 22 October 2022, when the unit reached criticality for the first time. In early January 2023, the operator completed the physical stage of the commissioning and launched power start-up testing. Once the reactor power was increased to 20%, and the steam generators produced a sufficient volume of steam, the turbine generators were connected to the national electrical system on 31 January 2023 and first megawatts of low-carbon electricity started flowing into the grid. To date, the commissioning process is still in progress.

But what does this mean for Slovakia and the nuclear industry in Central-Eastern Europe?

The new nuclear unit in Mochovce will have an installed capacity of 471 megawatts at start-up (extendable to more than 500 MW in the future). This will cover approximately 13% of Slovakia’s total electricity demand, equivalent to one and half million households. In 2023, Slovakia will become energy self-sufficient once again with the share of nuclear in electricity generation accounting for over 60%.

The planned lifetime of the new unit is 60 years (at least) which is an important factor for young people who are now deciding on their future careers. It is our responsibility to show them the perspectives that nuclear industry can offer, because it is a large-scale decarbonizing instrument in line with Europe’s long-term energy policy. That is why we are also intensifying cooperation with local universities and high schools and promoting the sustainable energy mix topic in the state-of-the-art Energoland information centre at Mochovce, that welcomes approximately 15 thousand visitors a year.

Thanks to our long commitment, but also the current focus on European energy dependency and the ongoing energy crisis, we have seen gradual improvements in public opinion. Seven out of ten Slovaks, and even nine out of ten living in nuclear power plant regions, support nuclear energy, according to a poll performed in June-July last year – that is another crucial indicator providing preconditions to encourage more young people to consider long-term high-skilled jobs in a carbon-free industry.

Slovenské elektrárne, as the only company from Slovakia and Eastern Europe, has been ranked under Europe´s Climate Leaders list compiled by the Financial Times daily in two consecutive years (2021 and 2022) based on a decrease in emissions intensity.