The International Atomic Energy Agency rotated its teams at Ukraine’s Zaporizhzhya Nuclear Power Plant (ZNPP) today. Since the Agency established a continued presence at the site in September 2022, 20 teams of experts have crossed the frontline of the conflict in Ukraine to reach the plant, Director General Rafael Mariano Grossi said.
The rotation took place one day after Director General Grossi met with Swiss Foreign Minister Ignazio Cassis, ahead of the Swiss-hosted Summit on Peace in Ukraine, scheduled for June 15 and 16. Director General Grossi briefed Foreign Minister Cassis on the IAEA’s unique role in preventing a nuclear or radiological accident amid the ongoing military conflict.
“The IAEA is the only international organization with a permanent presence at nuclear facilities in Ukraine, including the Zaporizhzhya Nuclear Power Plant. We continue to provide technical support and independent information to the world,” said Director General Grossi. “I urge all states attending the Peace Summit to strengthen and support the unique, independent, and technical role of the IAEA.”
On the ground, the IAEA team at ZNPP reported hearing explosions, including close to the plant, on several days over the past week. They confirmed with the plant that one of the mines located next to the ZNPP cooling pond area exploded on 11 June. There were no physical damage or casualties from the explosion and the cause of the explosion was not shared with the IAEA team.
“This latest explosion, so close to the plant, is of grave concern and is aggravating an already fragile situation,” said Director General Grossi, who continued that “nuclear safety and security of the ZNPP cannot be compromised.”
On Monday, the IAEA experts visited one of the electrical sub-stations located in the nearby town of Enerhodar. The purpose was to observe the impact of an alleged shelling which, according to the ZNPP, occurred on 8 June. The alleged shelling resulted in a fire and damage to the substation which serves the Enerhodar city council building where the main communication hub between the ZNPP and Enerhodar is located. The ZNPP confirmed that the damage did not interrupt the communication lines.
Last week, the IAEA team observed testing of one of the safety trains in Unit 2 at the plant. Nuclear power reactors, such as those at the ZNPP, each have three separate and independent redundant systems – known as safety trains – comprising their safety systems. The planned test simulated the loss of regular power supply to one of the safety trains, which required the emergency diesel generator of that safety train to activate to supply the power required. The team was informed by the ZNPP that the test was successful, and no issues were identified.
During meetings with the ZNPP over the past week, the IAEA team discussed the number and qualification of staff working in the main control room of the plant. The ZNPP confirmed that, with all six units being in cold shutdown, three authorized personnel would be on duty for each shift in the main control room, with a minimum requirement for two to be present at all times.
As part of its regular walk downs of the plant, the team earlier this week visited the pumping station of Unit 4 where one circulation pump is used to maintain the flow of cooling water between the ZNPP discharge and intake channels. The operation of the circulation pumps is dependent on the overall water level in the ZNPP cooling pond, which continues to drop after the destruction of the Kakhovka dam in June 2023. The IAEA experts were recently informed that the ZNPP has installed a submersible pump near the isolation gate of the discharge channel of the Zaporizhzhya Thermal Power Plant, which is capable of pumping 100 m3 of water per hour from the Kakhovka reservoir into the channel, which is then pumped into the ZNPP cooling pond. The 12 sprinkler ponds used to cool the six reactors and safety systems continue to be fed with approximately 250 m3 of water per hour from 11 groundwater wells.
This week, the team also observed the real-time monitoring system of the storage casks, containing spent fuel from all six reactors, at the ZNPP dry spent fuel storage facility.
Emergency preparedness and response arrangements are crucial for nuclear safety at any nuclear power plant. The IAEA team engaged in discussions with ZNPP regarding the outcomes of the emergency drill conducted at the plant on 15 May. ZNPP confirmed that the drill successfully achieved its objectives and identified several valuable lessons. An action plan is being implemented to address the areas identified for improvement during the drill.
At Ukraine’s other nuclear power plants - Khelmnytskyy, Rivne and South Ukraine, and the Chornobyl site - IAEA teams continue to perform routine walkdowns and conduct meetings with the facilities to assess nuclear safety and security. The teams reported that despite the effects of the ongoing conflict, including air raid alarms over the past week, nuclear safety and security is being maintained. Nevertheless, the IAEA is continuing to follow the situation with regard to external power very closely at each of these plants, where a loss of off-site power event has the potential to be serious given the higher nuclear fuel temperatures for reactors in operation in Ukraine.
The teams reported that one reactor unit at both the Rivne and South Ukraine NPPs remains shut down for planned maintenance and refuelling, while one other unit at the South Ukraine NPP resumed operations after the completion of its scheduled maintenance and refuelling, which concluded safely and successfully.
Over the past two days, the IAEA experts observed a large scale emergency exercise conducted at the South Ukraine NPP which also included participation from the Khelmnytskyy and Rivne NPPs.
The teams at Khelmnytskyy, Rivne and South Ukraine have all rotated over the last week.