The reactor assembly of the third unit at the Mochovce nuclear power plant, pictured in June 2016. (source: SME)
The third reactor unit of the Mochovce nuclear power plant in western Slovakia should finally enter into full operation at the beginning of next year, CEO Branislav Strýček of Slovenské Elektrárne (SE), the plant's operator, confirmed on Thursday, August 25. He was speaking in response to a second-instance decision issued by Slovakia's Nuclear Regulatory Authority (ÚJD) in which it rejected an appeal against the unit's launch and confirmed the first-instance decision permitting it to go ahead.
SE, which is the country's main electrical power producer, will shortly commence loading nuclear fuel into the reactor, a process which is scheduled to take 18 weeks, during which the unit should start supplying power to the grid.
“The ÚJD consistently checked and evaluated all areas, demonstrating the technical and qualitative readiness of the third unit for fuel loading,” said Marta Žiaková, head of the ÚJD, as quoted by the SITA newswire. “The readiness of the reactor block for the loading of the first fuel assembly and the start of active tests had to be demonstrated comprehensively by the investor in all assessed areas.”
SE will start loading the fuel into the reactor after 15 days, that is, after the ÚJD’s decision becomes final.
“Eighteen weeks after the fuel is loaded, we will be at full capacity,” said SE's Strýček, as quoted by the TASR newswire. “Our highest priority in electricity production is always safety, and we will proceed in the same way when putting the unit into operation. We have decades of experience in the operation of nuclear units and a team of internationally recognised experts, who will have this entire process under control.”
The commissioning phase ends after all physical and energy start-up tests have been carried out, with a 144-hour proof run at full power. The reactor block will start supplying electricity to the grid after connection of one of the generators, which will happen at 20 percent nominal power during energy start-up.
Prime Minister Eduard Heger (OĽaNO) pointed out that Slovakia has been waiting a very long time for the launch of the third unit at Mochovce, but safety had to be put first. However, the timing of the launch of the third unit’s operation has turned out to be quite felicitous.
“It has come at a rather suitable time, as we’re currently facing a big energy crisis,” Heger said, adding that nuclear's share of Slovakia's energy mix is now about to swell from 52 percent to 65 percent.
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, 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 whole construction process accompanied by allegations of mismanagement.
The installed capacity of the third unit will be 471 megawatts (MW), enough to provide approximately 13 percent of the country's overall electricity consumption. Once the third unit is operating at full power output following its trial run Slovakia will be self-sufficient in electricity generation.
