External power has been restored to Ukraine’s Zaporizhzhya Nuclear Power Plant (ZNPP) two days after it lost all access to off-site electricity in the latest incident highlighting the precarious nuclear safety and security situation at Europe’s largest such facility, Director General Rafael Mariano Grossi of the International Atomic Energy Agency (IAEA) said today.
Both the ZNPP’s external power lines, a 750 kilovolt (kV) line and a 330 kV back-up line used for electricity supplies from the grid, were repaired, and reconnection started on Friday afternoon. At around 22:00 the 750 kV power supply to all six units of the ZNPP had been re-established, and the eight operating emergency diesel generators turned off and put into standby mode, Director General Grossi said, citing information he had received from the team of IAEA experts present at the plant.
The 750 kV line is therefore now once again providing the electricity the ZNPP’s six reactors need for cooling and other essential nuclear safety and security functions, including unit 4 which had earlier lost its connection to the 750 kV line in a landmine explosion late last month. The 330 kV external power line to the nearby thermal power plant switchyard is also available to provide back-up power to ZNPP.
This 750 kV line was disconnected from the entire ZNPP site following shelling late on Wednesday and the 330 kV line was also lost just a few hours later, with both sustaining physical damage around 50-60 kilometres from the plant in Ukrainian-controlled territory. The ZNPP’s emergency diesel generators automatically started generating back-up power until external power was restored. At that time, the plant had fuel for around 15 days of diesel generator operations. The IAEA team has been informed that supplies of diesel fuel continue to be delivered to the site, and today plant staff plan to refill the tanks of all the diesel generators.
There is no change in the operational status of all units. Units 5 and 6 are in semi-hot shutdown providing steam to the site and arrangements are being made to further heat-up both units to a hot shutdown state. The other four units remain in cold shutdown.
The ZNPP had already lost external power several times during the current conflict in Ukraine, forcing it to rely on the diesel generators until off-site electricity became available again.
“The repeated power outages all too clearly demonstrate the extremely serious nuclear safety and security situation this major nuclear power plant is facing. So far, the brave staff of the Zaporizhzhya Nuclear Power Plant have always managed to maintain the safe operation of the six units. But it can’t go on like this. I have repeatedly called for the urgent establishment of a nuclear safety and security protection zone around the Zaporizhzhya Nuclear Power Plant to prevent a nuclear accident. We can’t afford to lose any more time. We must act before it is too late,” Director General Grossi said.
In recent weeks, Director General Grossi has engaged in high-level talks with both Ukraine and Russia aimed at agreeing and implementing such a zone around the ZNPP as soon as possible.