Slovak nuclear power plant Mochovce 3 reaches 90% of installed capacity

The output of the third unit at Slovakia’s Mochovce nuclear power plant has been increased from 75% to 90%. Tests as part of the new reactor unit’s power start-up are continuing, Slovenské elektrárne announced. The VVER-440 unit is expected to enter commercial operation in the coming months.

The start-up process involves gradually increasing output, with tests carried out at different power levels. In March, the unit’s output was increased to 55% and in July to 75% of nominal capacity.

"After successfully completing all power start-up tests at 75% of the reactor’s rated output and submitting a report on the test results to the Slovak Nuclear Regulatory Authority, Slovenské elektrárne increased the output of the third unit’s reactor to 90%,"the company said.

The unit has so far supplied approximately 650 000 MWh of electricity to the grid, which, according to Slovenské elektrárne, is equivalent to the annual consumption of 260 000 households.

"The tests at 75% power were completed without delays, bringing us much closer to achieving full output at reactor unit 3," said Mochovce plant director Martin Mráz.

After the tests at 90% output are completed, the reactor’s output will be increased to 100%.

"The 144-hour demonstration run at 100% output will confirm the full functionality of unit 3 and its achievement of design parameters, bringing the power start-up phase to a close. This milestone is expected to be reached between September and October", Slovenské elektrárne said.

Fourth unit’s start-up date not yet specified

Construction of the first two VVER-440 units at the four-unit Mochovce plant began in 1982. Work on units 3 and 4 began in 1986 but was suspended in 1992. The first two reactors were completed and commissioned in 1998 and 1999, respectively. The project to complete units 3 and 4 began ten years later. The schedule for completing the unit envisaged its start-up 1-2 years after the start-up of EMO 3. The main priority now, however, is to begin commercial operation of the third unit.

Each reactor unit at the Mochovce nuclear power plant will be capable of covering 13% of Slovakia’s electricity consumption at nominal output. Slovakia expects to become a net exporter of electricity once both new units at Mochovce are commissioned.