Unit 2 of Slovakia’s Mochovce nuclear power plant has restarted, following an upgrade, with its power increased from 470MWe to 500MWe, power utility Slovenské elektrárne said on 4 November.

In August, the NPP began replacing the first of the VVER-440 reactor’s two turbines, which meant the unit was working at only half capacity. From mid September, the work during the routine outage of the plant, and after its completion it continued to operate at 50% power with one turbine replaced. Work on replacement of the second turbine continued, and on 29 October it was phased into the electricity system at tested at various power levels.

As part of the work, the huge 100-ton high-pressure part as well as the low-pressure parts of the turbine, the electronic regulator and large 400-kilovolt block transformers were replaced on both turbines. The turbines will undergo dynamic tests before final acceptance from the supplier. The work was undertaken in compliance with stringent COVID-19 restrictions.

"Completion of the project unit 2 of the Mochovce plant should add up to 225GWh a year to electricity production, which represents approximately the annual consumption of 80,000 Slovak households, all without increasing nuclear fuel or personnel costs,” said plant director Martin Mráz. “In the coming years, this will even result in reducing the cost of maintaining the reliability of the equipment."

The service life of the turbines following the upgrade will be 40 years. Mochovce 2 began operation in 1999.

Photo: Turbine parts for TG22 were dispatched to the Mochovce Nuclear Power Plant earlier this year (Credit: Doosan Škoda Power)