A third reactor block at Mochovce nuclear power plant was connected to Slovakia's energy grid for the first time on Tuesday - 11 years later than planned.
Electricity producer Slovenské Elektrárne (SE) phased in the first of its two turbine-generators at the plant in the Nitra Region shortly before midnight on Tuesday, with the third unit beginning to deliver electricity. The reactor is currently at 20 percent of nominal power.
“Today represents a fundamental milestone for Slovenské Elektrárne, the community of nuclear energy workers and the entire country,” said Branislav Strýček, chairman of the Board and CEO of the partly state-controlled Slovenské Elektráne. “The new unit will significantly contribute not only to energy stability, but also to the commitment to reduce greenhouse gas emissions on the way to carbon neutrality.”
Strýček said its operation will help SE meet an agreement with the government to supply cheap electricity for households at a price of €61.2077 per megawatt hour.
The company has said that in the coming weeks it will be running tests ion the unit at different power levels from 35 to 100 percent.

Construction resumed in 2008
Construction of the Mochovce nuclear power plant was launched during the communist regime in the 1980s. The first two units of the plant, based on the Soviet (now Russian) VVER design, were completed and commissioned in 1998 and 2000 respectively. When work resumed on the second two units in late 2008, they were scheduled for completion by 2012 and 2013, respectively, at a projected cost of €2.8 billion. Since then the budget has more than doubled to €6.2 billion, the deadline has repeatedly been set back, and the construction process has been plagued by allegations of mismanagement.
The permit to put Mochovce into operation was issued by the Nuclear Regulatory Authority (ÚJD) last summer, loading of fuel ended in September. The first stage of start-up, during which small leaks appeared on the reactor block, was completed by SE in January 2022.
The new nuclear unit in Mochovce - which has an expected lifespan of 60 years at least - will have an installed capacity of 471 megawatts at start-up, covering approximately 13 percent of Slovakia’s total electricity consumption, making Slovakia self-sufficient in electricity production.
SE plans to launch Mochovce’s fourth unit 23 months after the commissioning of the third unit.