Ukrainian engineers have managed to restore back-up power to the Zaporizhzhya Nuclear Power Plant (ZNPP), a much-needed development after the plant twice over the past week lost all access to external electricity, Director General Rafael Mariano Grossi of the International Atomic Energy Agency (IAEA) said today.
The availability of back-up off-site electricity through the switchyard of the nearby thermal power station provides Europe’s largest nuclear power plant with a buffer if the connection to its last remaining operating 750 kilovolt (kV) power line were to be cut again, the Director General said.
When the ZNPP’s connection to the high-voltage line was temporarily cut on Saturday and again on Wednesday due to damage caused by shelling, the plant had to rely on its emergency diesel generators for electricity until the line was restored.
In recent days, two of the ZNPP’s back-up power lines – connecting it to the thermal power plant switchyards – have been repaired, the IAEA team at the site reported to Agency headquarters. Today, one of the 330 kV external lines connecting the switchyard of the thermal power plant to the grid was also restored, enabling the plant to receive electricity that way, if needed.
“Working in very challenging conditions, operating staff at the Zaporizhzhya Nuclear Power Plant are doing everything they can to bolster its fragile off-site power situation. Restoring the back-up power connection is a positive step in this regard, even though the overall nuclear safety and security situation remains precarious,” Director General Grossi said.
Before the conflict, the ZNPP had access to the grid through four high-voltage power lines, but three of them have fallen victim to the fighting. The back-up power lines – offering indirect access to the electricity grid – had also been down in recent weeks.
A secure off-site power supply from the grid is essential for ensuring nuclear safety, also with the six reactors in a shutdown mode. This requirement is among the seven indispensable nuclear safety and security pillars that the Director General outlined at the beginning of the conflict.
The IAEA team also said further preparatory activities to restart reactor unit 5 were continuing, and that work to also restart unit 6 was expected to get under way tomorrow. Restart will take a number of days.
Separately, the ZNPP has received additional fuel supplies for its 20 diesel generators, following the arrival of seven trucks, of which five recently came from the city of Zaporizhzhya, and two earlier from Russian-controlled territory, the IAEA team said. The plant currently has fuel for at least ten days operation of diesel should external power be lost.
Director General Grossi has in recent weeks engaged in high-level consultations with Ukraine and Russia aimed at agreeing and implementing a nuclear safety and security protection zone around the ZNPP as soon as possible, stressing it is urgently needed to help prevent a nuclear accident. The consultations are progressing.
During recent high-level meetings in Ukraine and Russia, he has also raised the increasingly difficult and challenging work conditions for the ZNPP’s Ukrainian staff. They are facing “unacceptable pressure”, he said, due to demands to sign a new employment contract with Russian state company Rosatom to keep their jobs, while national Ukrainian operator Energoatom is urging them not to do so and instead follow its instructions.
“I made clear that the staff must be allowed to carry out their vital tasks without undue interference or pressure,” the Director General said.
Since early August, there has been frequent shelling at or near the ZNPP, causing widespread concern about nuclear safety and security at the site. In the past few days, the IAEA team said, there appears to have been little shelling in the vicinity of the plant itself. However, there were two landmine explosions in the afternoon today outside the ZNPP perimeter fence.