Maxar satellite imagery of the before/after close-up views of Nova Kakhovka dam and hydroelectric power facility.Satellite image (c) 2023 Maxar Technologies

In June, a controlled explosion caused the Ukrainian Kakhovka hydroelectric dam to collapse.

An international investigative group says it's "highly likely" Russian forces were behind the attack.

The nearby Zaporizhzhia nuclear plant relies on water reserves to cool its power reactors.

Residents near the Zaporizhzhia nuclear power plant in Ukraine are preparing for a meltdown after a critical dam collapsed last month, threatening the water supply needed to cool the plant's nuclear reactors.

The New York Times reported Nadiya Hez, a nurse who lives in an area close enough to the plant to bear the brunt of any potential nuclear fallout, now keeps iodine tablets on hand and has made an old root cellar available to hide in with her husband and their 1-year-old son, should catastrophe strike nearby.

"I'm terrified," Olena Pareniuk, a Ukrainian bio-radiologist in Kyiv, told the outlet.

In October, Ukrainian President Volodymyr Zelenskyy warned that Russian forces, who had captured the key piece of infrastructure, rigged the dam to explode, Insider previously reported. An international investigative group said after the explosion it's "highly likely" Russian forces were behind the attack.

Zelenskyy said the loss of the dam could flood a vast area and deprive the south of Ukraine of its water supply. It did, killing at least 52 people, Reuters reported. He also said the loss of the dam could also endanger the Zaporizhzhia Nuclear Power Plant, which draws on the reservoir at nearby Kakhovka for cooling.

Now, the more dire of the Ukrainian leader's predictions may come true. While the Zaporizhzhia plant's reactors currently have several months worth of water from an existing cooling pond, according to the UN's International Atomic Energy Agency, it is critical for the safety of the plant to find a new water source to cool the reactors.

According to the IAEA, only one of the six reactors at the plant remains hot. The others are in a state of cold shutdown, lowering the risk of meltdown due to loss of cooling. However, the height of the cooling pond is declining by up to 1 centimeter per day due to site usage and evaporation, according to a Friday statement from the IAEA.

Though a drainage system is currently replenishing the water, lowering the reduction rate, the agency is urgently seeking solutions for a new way to keep the plant cool.

Representatives for the UN's International Atomic Energy Agency did not immediately respond to Insider's request for comment.

The security of the Zaporizhzhia plant — Europe's largest nuclear power plant — has been of paramount concern since the beginning of Russia's invasion of Ukraine, with Russian leader Vladimir Putin targeting the plant early on.

In response, five basic principles for the protection of the plant were established by IAEA Director General Rafael Mariano Grossi at the United Nations Security Council. The principles state there should be no attack from or against the plant and that it should not be used as storage or a base for heavy weapons like rocket launchers, artillery systems and munitions, and tanks.

Recently, however, the IAEA has received reports of mines placed around the Zaporizhzhia Nuclear Power Plant, a violation of the UN principles and a significant risk to the security of the nuclear reactors.

"We need full access to be able to confirm that the five principles have not been violated, and we will continue to request the necessary access to all those areas essential to nuclear safety and security so that we can deliver on this mandate, including that the plant should not be used as storage or base for heavy weapons and munitions," Grossi said in a Friday IAEA statement, adding that the agency's investigative team that monitors the site had not reported any shelling or explosions over the past week and that the Russian military presence at the site appears unchanged.

He added: "We are reinforcing our own presence at the plant to monitor compliance with these principles that are of paramount importance for protecting the plant and preventing a major nuclear accident during the war."