Slovenské elektrárne says that Mochovce 3's energy start-up has now seen its output increased to 55% - with the final trial run at 100% power for six days and nights expected to take place in May and June.
The new unit at the Mochovce nuclear power plant in Slovakia was connected to the grid for the first time at 20% of its nominal power on 31 January.
Since then, with tests and checks taking place, the power has been increased in stages - Slovenské elektrárne says that in total it has produced more than 150 GWh of electricity and at its current output level it is producing enough electricity to supply the needs of three-quarters of a million households. The final stage is running the new unit for 144 hours at 100% output.
Construction of the first two 471 MWe VVER 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.
The final design includes many upgrades to safety and security, including increased aircraft impact protection and emergency management measures based on lessons from the Fukushima accident which were incorporated during the project. The Slovak Nuclear Regulatory Authority issued the final authorisation for commissioning of unit 3 of the Mochovce plant in August. The service life of the new block is initially planned to be 60 years.
Slovenské elektrárne, which is equally owned by the state, Italy's Enel and the Czech EPH group started by billionaire Daniel Kretinsky, has also signed an extension to its supply-and-pricing agreement with the country's ministry of economy and ministry of finance, agreed last year as part of extraordinary measures aimed at curbing the impact of high energy prices.
The original agreement was for the company to supply 6.15 TWh of electricity per year for 2023 and 2024 at a well-below-market price of EUR61.20 (USD66.60) per MWh. This has now been extended to supply 5.5 TWh of electricity to households per year for 2025 at a price of EUR66.70/MWh, rising to EUR72.70 in 2026 and EUR79.30 in 2027.
The agreement is subject to approval by the European Commission.
Branislav Strýček, CEO of Slovak Power Plants, said: "The agreement provides households with electricity for a long period under predictable and extremely favourable conditions. At the same time, the government has committed itself that in the years 2023 to 2027 it will not develop an initiative or support any initiative towards the Slovak Power Plants aimed at the introduction, increase or tightening of any new tax, levy, fee, specific payment or regulation, thereby ensuring a stable regulatory environment for the Slovak power plants."
Slovakia expects to become a net exporter of energy once the two new units at Mochovce are both up and running.
