Ukraine's Zaporizhzhya Nuclear Power Plant (ZNPP) has for more than a week relied on a single power line to supply the electricity it needs for essential nuclear safety functions, with the military conflict hampering efforts to restore the connection to its back-up line, Director General Rafael Mariano Grossi of the International Atomic Energy Agency (IAEA) said today.
The ZNPP's only remaining 330 kilovolt (kV) back-up line was disconnected on 7 May, leaving the plant entirely dependent on the only functioning 750 kV line. The IAEA was informed that the damage occurred in Ukrainian-controlled territory some distance away from the plant and that the Ukrainian grid operator cannot currently carry out repairs due to the active military situation in this area.
The ZNPP's six reactors have been shut down since mid-2022 but they still require off-site power to cool the fuel and minimise the risk of an accident. Before the conflict, the plant had access to ten power lines, ensuring reliable off-site power.
"Throughout the war, off-site power has been the main Achilles heel for nuclear safety and security at the Zaporizhzhya Nuclear Power Plant. The situation has, unfortunately, not improved in this regard. Our experts on the ground will continue to monitor developments very closely and we will continue to inform the world about nuclear safety and security at the plant, which remains precarious," Director General Grossi said.
The IAEA team has continued to hear military activities every day over the past week, with explosions at different distances from the ZNPP and early on Tuesday morning, the team also heard gun fire and what appeared to be the sound of a drone.
As part of their daily activities to monitor and assess nuclear safety and security, the IAEA team observed six of the site's 20 emergency diesel generators (EDGs). EDGs provide back up support in case a nuclear power plant (NPP) were to lose access to all off-site electricity, something which has happened eight times at the ZNPP during the conflict.
The team observed a loose screw on two of the EDGs, and saw indications that some activities may have recently been conducted on one of them. The ZNPP stated that there had not been any maintenance performed recently but acknowledged that the screws should not have been loose, one of which they said was due to vibrations. The IAEA team plan to observe scheduled testing of one of these EDGs in the coming days.
Mobile diesel boilers that provided heat to the ZNPP and the nearby city of Enerhodar during the cold winter months have now been shut down to perform hydraulic tests on the grid water system, the team also reported.
Director General Grossi said he continued to engage intensively with both sides to organise the next rotation of IAEA experts at the plant, which is already delayed because of the complex and difficult situation on the ground in the area located on the frontline of the conflict.
Planned maintenance and refuelling activities have continued to take place at Ukraine's three operating NPPs - Khmelnytskyy, Rivne and South Ukraine. One reactor unit at the Rivne NPP has returned to full power generation over the past week, so there are now a total of six reactors operating in Ukraine.
At the three plants and the Chornobyl site, the IAEA teams continued to report several air-raid alarms over the past week. The Agency teams at Rivne, South Ukraine and Chornobyl rotated over the past week, with staff from headquarters in Vienna replacing their colleagues in the field.
