Powerful explosions shook windows at the site of Ukraine's Zaporizhzhya Nuclear Power Plant (ZNPP) this week, underlining the urgent need for maximum military restraint to reduce the danger of a nuclear accident as the conflict enters its third year, Director General Rafael Mariano Grossi of the International Atomic Energy Agency (IAEA) said today.
IAEA experts stationed at the ZNPP reported hearing explosions every day over the past week, including one late last Friday that appeared to occur close to the plant itself. There were also several explosions yesterday. One of them was unusually loud, indicating very close proximity to the site.
It was not possible to conclusively determine the origin or direction of the blasts, with the exception of yesterday's large explosion, which according to the ZNPP was part of "field training" with no shelling of the plant nor any damage to it. There were no physical injuries or casualties, the plant added.
The ZNPP separately informed the IAEA team that a mine exploded outside the site perimeter earlier yesterday, without causing damage or injury.
"I remain deeply concerned about the nuclear safety and security situation at Europe's largest nuclear power plant, located on the frontline of the war. The reports of our experts indicate possible combat action not far away from the site. Once again, I call on all parties to strictly observe the five concrete principles for the protection of the plant and avoid any attack or military activity that could threaten nuclear safety and security there," Director General Grossi said.
In another indication of persistent nuclear safety and security risks facing the ZNPP, the site remains without back-up power, three days after the connection to its last 330 kilovolt (kV) line was cut due to a problem that occurred on the other side of the Dnipro river.
The ZNPP is still receiving the electricity it needs for reactor cooling and other nuclear safety and security functions from its only remaining 750 kilovolt (kV) line, but it currently has no back-up options available for off-site power. The ZNPP said it had been informed by the Ukrainian grid operator that the 330 kV line was not expected to be reconnected to the site before 1 March.
"This situation leaves the plant very vulnerable to further disruptions in the supply of off-site power. It is essential that the back-up power line becomes available again as soon as possible," Director General Grossi said.
Earlier this week, the IAEA team went to the site's 750 kV electrical switchyard and observed that its status was unchanged since a previous visit last month. In addition to the single line that remains connected, the team saw spare parts for the repair of a second line, out of four 750 kV lines before the conflict. However, the site has no plans to start the repair work due to the conflict.
Yesterday, the IAEA team observed the periodic testing of one of the emergency diesel generators of reactor unit 4, the last line of defence to provide the electricity needed in case of a loss of all off-site power, which has happened eight times since the start of the armed conflict.
The experts also met with the ZNPP's electrical department to discuss the maintenance plans for the year and also visited the electrical control room where they could observe the status of the on-site and off-site power systems. The IAEA experts were informed that all ageing cabling and equipment related to the safety systems, including switchboards and batteries, have been replaced.
The team performed a walkdown of all six main control rooms in the reactors on 19 February. The team was able to collect safety parameters in reactor units 2, 3 and 4 and had the opportunity to view the regulatory authorizations of personnel. The team was informed that many of the operating staff present were in the process of transitioning from their Ukrainian licenses to "authorizations" issued by Rosteckhnadzor, the nuclear regulator of the Russian Federation.
The IAEA teams stationed at Ukraine's other nuclear power plants - Rivne, Khmelnytskyy and South Ukraine - rotated this week. The teams report that these three facilities as well as the Chornobyl site continue to perform their activities despite frequent air alarms, with no reports of nuclear safety and security issues at these sites. At the Chornobyl site, the team has recently observed increased military activity.
