International Atomic Energy Agency (IAEA) Director General Rafael Mariano Grossi, after returning from talks in Kyiv and at the Zaporizhia NPP (ZNPP), provided an update on the IAEA website.

His eighth mission to Ukraine since February 2022 took place amid reports of a Ukrainian counteroffensive being under way, including in the Zaporizhia region near the nuclear plant, which is currently controlled by Russia.

Since Russia took control of ZNPP in March 2022 as part of its special military operation in Ukraine, the Russian national guard has been protecting the station and in October, Russian President Vladimir Putin signed a decree formally transferring ZNPP to Russian jurisdiction under nuclear utility Rosenergoatom (part of Rosatom). A Russian Federal State Unitary Enterprise. Zaporizhia NPP was established by Rosenergoatom to operate the plant. However, Ukrainian nuclear utility Energoatom still claims ownership of the plant. IAEA has had experts permanent stationed at the plant – the Support & Assistance Mission to Zaporizhia (ISAMZ).

Reports by Russian military analysts continue to suggest that retaking control of ZNPP is one of the main objectives of the Ukrainian counter-offensive. Russia and Ukraine have blamed each other for shelling that has repeatedly downed power lines vital to cooling the reactors, which are shut down but which need a constant supply of electricity to keep the nuclear fuel inside cool and prevent a possible meltdown. Russia and Ukraine have also accused each other of destroying the Nova Kakhovka dam on the Dniepr River, which has depleted water levels in the nearby reservoir, putting at risk cooling water for the six ZNPP reactors.

“With military activities and tension intensifying in the area near the Zaporizhia Nuclear Power Plant, and with this month’s dam catastrophe further complicating the facility’s extremely challenging nuclear safety and security status, it was very important for me to travel to the site again to review developments on the ground, including the plant’s ongoing and planned measures to manage the new water-related difficulties,” Grossi said.

Grossi said he was able to see first-hand how the level of the Kakhovka reservoir had declined markedly over the past ten days – even exposing previously submerged sand banks – but also that the plant’s large cooling pond and different channels at or near the site hold sufficient reserves to be able to provide cooling water in the short to medium term in case the reservoir can no longer be used.

At the moment, water from the discharge channel of the nearby Zaporizhia Thermal Power Plant (ZTPP) supplies the ZNPP’s spray ponds, which cool the six shut down reactors and used fuel, and also keeps the separate cooling pond full, mainly compensating for evaporation.

Together, the discharge channel and the large cooling pond can provide cooling water for some months provided they stay intact, although it is difficult to say exactly how long the existing water reserves can last in view of various external factors, such as evaporation and any future leaks.

There are also indications that some water resources from the reservoir itself currently remain available in areas near the ZNPP – where the water loss stopped a few days ago, unlike in other parts of the reservoir – but it is unclear if the level is high enough to pump it up for use at the plant. The pumps were last in operation about a week ago.

Together with a team of IAEA experts, Grossi evaluated all the main parts of the site’s water supply systems, including the gates separating the large pond and the ZTPP discharge channel from the reservoir, and how the plant is seeking to ensure that these bodies of water are kept secure and preserved.

For example, the plant has completed activities to seal and reinforce the isolation gates to prevent leakage. Grossi witnessed how they had been reinforced with counterweights and sand. “The integrity of these gates must be maintained to ensure that the plant has enough water for cooling the reactors. At the same time, it is essential that the plant implements a longer-term solution. The IAEA team can assist and advise in this work,” he said.

The measures the plant is taking are buying it some extra time to prepare additional back-up water supply options, he added. The plant informed Grossi that additional cooling water can be pumped from an underground water system and on-site wells. But he said it is not yet known whether these wells can reliably provide all the required water. New pumps that can potentially continue to access water at lower reservoir levels may also be installed.

“The breach of the dam has identified vulnerable points in the plant’s water supply chain and there is a need to adapt the entire system to the new situation. But I could also see that the plant is taking concrete steps to address these challenges, stabilise the situation and enable the plant to ensure sufficient cooling water also in the future. The situation is serious, and it requires our continuous close monitoring. But, for now, it is being controlled,” he said.

The Director General had planned his mission to the ZNPP already before the dam was damaged to follow up on the establishment at the UN Security Council on 30 May of five basic IAEA principles for the protection of the plant at a time of heightened military risks, including that there must be no attacks at or from the site and that it must not be used as a store for heavy weapons.

“From now on, we will be monitoring compliance with these principles, which are designed to prevent a nuclear accident during the armed conflict, which is showing clear signs of intensifying in the region where the plant is located. This requires a strengthened IAEA presence,” he said.

Underlining the tense situation in the area, Grossi’s convoy was stopped on the way back from the site visit, and gunfire was heard for a few minutes. But Grossi said the convoy was not in immediate danger and the IAEA does not have any other information about the incident.

During the mission, Grossi carried out a new rotation of IAEA experts at the site, bringing with him the ninth such team since the mission at the site was established nearly ten months ago. Although the rotations continue to take place regularly, there have been several delays and postponements, sometimes caused by the weather and the general security situation.

He also went to the ZTPP a few kilometres from the nuclear plant, whose damaged electrical switchyard in the past has been used to provide 330 kilovolt (kV) back-up power to the ZNPP. The plant’s last 330 kV back-up line was damaged almost four months ago, and the IAEA had requested access to the switchyard to check its status.

The ZNPP is continuing to operate one of the six reactors in hot shutdown to produce steam needed for wastewater treatment and a steam-driven cooling system that provides air conditioning for rooms equipped with instrumentation and control systems important to nuclear safety and security. Meanwhile the plant is also exploring alternate ways to meet the site’s needs for generating steam and providing essential cooling. The five other units remain in cold shutdown.

Elsewhere in Ukraine over the past week, the IAEA also carried out rotations of its expert teams at the country’s other NPPs – the Khmelnitsky, Rivne, South Ukraine and Chornobyl NPPs. In addition, the IAEA conducted its first medical assistance mission to the NPPs.

Dmitry Astrakhan of Izvestia news agency was one of the many reporters who were present during Grossi’s visit to ZNPP. He noted: “While waiting for the IAEA delegation, Adviser to Rosenergoatom Director General Renat Karchaa told reporters about the situation at the plant. According to him, periodic artillery attacks from the Ukrainian side pose a threat to the cooling system of the NPP. Splash pools are part of this system and are a closed loop. Their bottom is lined with a special waterproofing material. If a projectile damages this material, the water will sink into the sand.

In addition, the shelling has already caused damage to the pipes. To repair them, the pools had to be temporarily drained. After that, fragments of an American M777 howitzer shell were found in the tank.”

He continued: “According to Karchaa, the shelling also poses another danger. The cooling pond is separated from the Kakhovsky reservoir by special metal valves, called sandors. After the disaster at the Kakhovskaya hydroelectric power station, the station staff further strengthened them. Today, the water level in the reservoir is 11 metres – which is much lower than in the pond. We were personally convinced of this on the shore. The difference in the water level in the two reservoirs is visible to the naked eye.”

Astrakhan said Grossi arrived in a Russian white UAZ Patriot, accompanied by two Typhoon armored vehicles…. The IAEA delegation inspected the territory. The station director showed the head of the agency the damage caused by shelling on the splash pools. In particular, he demonstrated a broken pipe and found fragments from the M777 artillery system.

Astrakhan commented: “On his last visit to the station, Grossi would constantly say, ‘Yes, it's very bad.’ Today, he repeated a different phrase: "Yes, everything is clear." Either the CEO is already used to bad news, or he really fully understands the situation.”

During the inspection of the pumping station, Renat Karchaa drew attention to which side of the building there were traces of shrapnel. “This clearly indicated that the shelling was conducted from the territory controlled by Ukraine,” Astrakhan said.


Image courtesy of IAEA