Zaporizhzhia temporarily loses grid connection

26 August 2022

Ukraine's Zaporizhzhia nuclear power plant has been reconnected to the grid after hostilities in the area led to the damage of the last remaining operational 750 kilovolt external power line connecting the plant to the national grid.

The six unit Zaporizhzhia plant (Image: Energoatom)

Nuclear power plant operator Energoatom said the PL-750 kV Dniprovska overhead line was disconnected at least twice on 25 August. It said the three other 750 kV power lines connecting the Zaporizhzhia plant to the grid were previously damaged during the conflict.

As a result, the plant's two operating reactors - units 5 and 6 - were disconnected from the grid. "Thus, the actions of the invaders caused a complete blackout of the Zaporizhzhia nuclear power plant from the energy grid - the first in the history of the station," Energoatom said.

It noted the plant remained connected to a 330 kV line from a nearby thermal power facility, which maintained the plant's own electricity needs.

Energoatom said two damaged transmission lines have now been reconnected and "provide a reliable power supply for balance of plant needs of the Zaporizhzhia plant. This ensures the steady energy supply and safe operation of used nuclear fuel stores and other important facilities on the site." In addition, it said workers will soon restore one more transmission line, "which will help enhance the operational safety of the power plant."

Ukraine informed the International Atomic Energy Agency (IAEA) that all six units at Zaporizhzhia remained disconnected from the grid after the power line was restored.

IAEA Director General Rafael Mariano Grossi said the temporary loss of grid connection further underlines the urgent need for an IAEA expert mission to travel to the facility.

A secure off-site power supply from the grid is essential for ensuring nuclear safety, the IAEA said. This requirement is among the seven indispensable nuclear safety and security pillars that Grossi outlined at the beginning of the conflict. In the case of a loss of external power, the Zaporizhzhia plant - like other nuclear power plants around the world - still has diesel generators available to provide back-up power.

"Almost every day there is a new incident at or near the Zaporizhzhia nuclear power plant," Grossi said. "We can't afford to lose any more time. I'm determined to personally lead an IAEA mission to the plant in the next few days to help stabilise the nuclear safety and security situation there."

The Zaporizhzhia plant has been under Russian military control since early March, but continues to be operated by its Ukrainian staff. It is the first time a nuclear power plant has been occupied by a military force. There has been continued military action in and around it, with both sides blaming the other for the intensified shelling over the past few weeks.

Researched and written by World Nuclear News