The UN nuclear watchdog said on June 16 after a visit by its chief to the Zaporizhzhya Nuclear Power Plant in Ukraine that it was unclear whether water from the Kakhovka dam's reservoir can still be pumped to the plant.
There are indications that some water from the reservoir remains available, but it is unclear if the level is high enough to pump it for use at the plant, the International Atomic Energy Agency (IAEA) said on June 16 in a statement.
The pumps, which were last in operation about a week ago, might be replaced with new ones "that can potentially continue to access water at lower reservoir levels," the IAEA said.
The reservoir was a main source of water for cooling the six reactors and filling ponds at the plant before the dam on the Dnieper River ruptured last week. Kyiv has accused Moscow of mining the dam and deliberately causing its destruction. Moscow denies any involvement and blames Ukraine.
The bursting of the dam has further complicated an already difficult situation at the Russian-occupied Zaporizhzhya plant, which has repeatedly been affected by downed external power lines that are also vital to ensuring the cooling necessary to prevent a nuclear meltdown.
IAEA chief Rafael Grossi led a delegation to the plant on June 15 and issued a detailed statement a day later.
"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," he said. "But I could also see that the plant is taking concrete steps to address these challenges, stabilize the situation, and enable the plant to ensure sufficient cooling water also in the future."
The situation requires continuous close monitoring, but for now it is being controlled, and there are measures being implemented to buy some time to prepare additional back-up water-supply options, Grossi added.
Grossi observed how the level of the reservoir has declined since the dam ruptured on June 6. He could see that the plant's large cooling pond and different channels at or near the site hold sufficient reserves to provide cooling water in the short to medium term in case the reservoir can no longer be used, the statement said.
Water from the discharge channel of the nearby Zaporizhzhya thermal power plant currently supplies the nuclear power plant's ponds, which cool the six shutdown reactors and spent fuel, he said. The water also keeps a separate cooling pond full.
Together, the discharge channel and the large cooling pond can provide cooling water for some months provided they stay intact, the statement said.
Plant officials informed Grossi that additional cooling water can be pumped from an underground water system and on-site wells, but it is not yet known whether these wells can provide all the water needed.
Grossi's visit was already scheduled before the dam burst as a follow-up to his proposal to the UN Security Council on May 30 of five principles for the protection of the plant. The principles include no attacks at or from the site and no storage of heavy weapons at the site.
"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," Grossi said.