Slovakia's Mochovce NPP Unit 4 First Grid Connection Delayed Due to Retest, Full Commercial Operation Expected Within the Year

Slovenské elektrárne announced on October 13 that due to the need to repeat a scheduled technical test, the grid synchronization and connection of Mochovce Nuclear Power Plant Unit 4, originally scheduled for that day, will be postponed by several days. The commissioning start-up procedures for the unit are still progressing steadily, and the overall project remains on track to enter full commercial operation before the end of this year.

Slovak Prime Minister Robert Fico had previously stated that the grid connection ceremony was scheduled for Tuesday, and he had originally planned to personally attend the event at the nuclear power plant site. Slovenské elektrárne explained in its statement that in response to a need to review certain local operating conditions identified during the commissioning process, the team decided to postpone the first synchronization and connection of Unit 4 to the national transmission grid; this adjustment is part of the standard control process during the nuclear power project commissioning phase, and the grid connection milestone is expected to be successfully achieved within the coming days.

Mochovce Nuclear Power Plant Unit 4 has an installed capacity of 471 megawatts (MWe). Slovenské elektrárne officially launched the physical start-up and power escalation procedures for the unit in September this year, gradually increasing the reactor thermal power in stages. According to engineering specifications, when the reactor power level reaches 20%, the turbine-generator set can meet the physical conditions for synchronization and connection to the Slovak national grid, thereby achieving the actual delivery of the first megawatt-hours of electricity to the public grid.

Mochovce Nuclear Power Plant is Slovakia's second nuclear power site. Following the successful grid connection and commissioning of Unit 3 in 2023, Unit 4 will be the last unit planned for construction at this nuclear power plant to be put into operation. Currently, the Czech energy investment group EPH Group holds a controlling stake in Slovenské elektrárne, while the Slovak government holds the remaining 34% stake and has publicly expressed its intention to further increase the state-owned shareholding ratio.

Slovenské elektrárne previously estimated that once Mochovce Unit 4 is fully operational, nuclear power's share of Slovakia's total national electricity consumption will jump to 77.5%, surpassing France in terms of nuclear power generation share and ranking first in the world. At the same time, the Slovak government is also planning a large-scale new nuclear power plant with an installed capacity of 1,200 megawatts (MW) to be invested in and built under state leadership, in order to further consolidate the country's low-carbon electricity self-sufficiency.