A recent Swiss-hosted "Summit on Peace in Ukraine" has highlighted wide international recognition of the crucial role of the International Atomic Energy Agency (IAEA) in preventing a nuclear accident during the conflict in Ukraine, Director General Rafael Mariano Grossi said today.
"I appreciate the strong support for the indispensable work of the IAEA expressed by the many countries and organizations attending the summit," Director General Grossi said.
At the largest of Ukraine's nuclear facilities - the Zaporizhzhya Nuclear Power Plant (ZNPP) - the IAEA team stationed at the site has continued to hear indications of military activity over the past week, including an explosion close to the site on 16 and again on 17 June. The ZNPP informed the IAEA experts that there had been no impact on or near the site itself. On most days, the IAEA experts also heard explosions further away from the site.
Persistent risks related to the availability of off-site power remain a source of deep concern for nuclear safety and security, as Ukraine's electricity grid has been severely impacted by the conflict, including extensive damage caused by infrastructure attacks in recent months.
In the latest indication of such dangers, the Luch sub-station in the city of Enerhodar was destroyed on Wednesday. The ZNPP informed the IAEA team that the cause of the destruction was a drone attack. This is the second time this sub-station has been damaged since 2022. Following this event, Enerhodar - where most ZNPP staff live and which had been powered by the Luch and Raduga sub-stations - lost electrical power on Wednesday evening. The IAEA team based at the ZNPP went to the Luch sub-station on Thursday, confirming it had been destroyed and was not operational.
The Luch sub-station usually provides electricity to parts of Enerhodar and to other areas, such as the water pumping station of the city, the industrial area and surrounding small towns. As of yesterday, parts of Enerhodar received electricity through the Raduga power line instead. Power supplies to the ZNPP were not directly affected this time, as it does not receive off-site power from either the Luch or Raduga power lines.
However, Director General Grossi said it was another stark reminder that it is essential to have a reliable connection between a nuclear power plant (NPP) and the external grid for maintaining nuclear safety, both for operational and shutdown plants. Although each NPP is designed to manage situations where the connection to the grid is cut, the loss of off-site power to any NPP is a significant event that must be protected against as a fundamental component of nuclear safety.
Any attack affecting the power supplies to any of Ukraine's NPPs would be a violation of the seven indispensable pillars for ensuring nuclear safety and security during the conflict, he said, noting that pillar four states that there "must be a secure off-site supply from the grid for all nuclear sites".
"I remain extremely concerned about the off-site power situation for Ukraine's nuclear power plants. The Zaporizhzhya Nuclear Power Plant - which has already lost access to most of its external power lines - is particularly vulnerable in this regard. It has repeatedly lost all off-site power during the conflict. The damaged sustained by the Luch sub-station had a direct impact on plant staff who live in Enerhodar, immediately adjacent to the plant, and therefore also an impact on nuclear safety and security. It is therefore essential that energy infrastructure be protected and preserved at all times," Director General Grossi said.
A team of IAEA experts on 20 June assesses damage at an electrical sub-station in the city of Enerhodar, home to many staff of the nearby Zaporizhzhya Nuclear Power Plant in Ukraine. (Credit: IAEA)
At the ZNPP, the IAEA experts have continued to conduct walkdowns as part of their regular activities to monitor nuclear safety and security and related developments across the site.
They are also continuing to closely monitor maintenance activities at the site, which are vital for maintaining nuclear safety and security but which have faced challenges during the conflict. The IAEA experts this week discussed the ZNPP's maintenance plan for reactor units 1 and 2, especially for the second half of 2024.
Over the last week, the ZNPP operated the four diesel steam generators (DSG) commissioned in early 2024 to treat 500m3 of liquid radioactive waste. The resulting treated water is intended to be re-used for plant operation. The generators were put back to standby mode on Tuesday after the completion of this task.
Separately on the same day, the main electrical transformer of reactor unit 2 was returned to operation after a month of maintenance, including tests on valves, sensors, electrical components, and oil. The IAEA experts were also informed that the ZNPP plans to purchase a spare transformer in the future.
The IAEA team this week also observed the testing of parts of the safety system of unit 5, including its emergency diesel generator (EDG). The ZNPP staff simulated a loss of power, which initiated the start of the EDG and left it in operation for 25 minutes before switching it back to standby mode.
On Wednesday, the IAEA experts visited the ZNPP training centre where they observed the installed mock-ups of different components of the plant and two of the three full-scope simulators, including Main Control Room operation shift staff undergoing training on one of them.
The IAEA experts present at the Khelmnytskyy, Rivne and South Ukraine NPPs and the Chornobyl site reported that nuclear safety and security is being maintained despite the effects of the ongoing conflict, including air raid alarms on several days over the past week.
Early on Thursday morning, the IAEA experts at the South Ukraine NPP went to the shelter in their hotel after hearing small arms fire nearby. They were later informed that a drone had been shot down in the vicinity of the hotel, but that it had not targeted the hotel or the NPP.
