On September 9, 2025, the head of the International Atomic Energy Agency (IAEA), Rafael Grossi, told the agency’s Board of Governors in Vienna that six out of seven key principles of nuclear safety have been violated at the Russian-occupied Zaporizhzhia nuclear power plant. The assessment highlights the depth of the risks surrounding Europe’s largest nuclear facility, seized by Russian forces in March 2022. Grossi stressed that the plant’s current condition is unsustainable and carries severe international security implications.
Fragile infrastructure and mounting risks
The IAEA noted that the plant is supplied by only one external power line, a precarious arrangement that leaves safety systems vulnerable to outages. Water levels in the cooling reservoir have dropped to 13.4 meters, nearing the critical threshold of 12 meters below which the reactors’ cooling systems would fail. Grossi called for the construction of a pumping station to stabilize cooling capacity. All six reactors remain in cold shutdown, and under current conditions none can be restarted safely.
Ukrainian energy officials described the situation as an “off-design threat,” warning that the plant is operating outside of any planned safety regime. The ministry emphasized that the consequences of such operation cannot be fully assessed under conditions of military occupation, where proper maintenance and oversight are impossible.
Russian control undermines safety
Moscow has replaced much of the original Ukrainian staff with its own personnel, raising concerns about competence and oversight. Reports of explosions, fires and nearly a dozen blackouts underscore the fragility of the plant’s infrastructure. Despite the IAEA’s continuous monitoring mission since 2022, Russian authorities continue to restrict inspectors’ access to critical areas, including a new dam near a cooling pond. Limited access prevents a full evaluation of risks and obscures the real condition of safety systems.
Analysts warn that any attempt by Moscow to connect the plant to Russia’s power grid ahead of the winter heating season would escalate the danger, as such integration would bypass international safety norms and be managed by inadequately trained staff.
Potential consequences for Europe
Experts caution that a severe nuclear accident at Zaporizhzhia could surpass both Chernobyl and Fukushima in scale. In the worst-case scenario, the exclusion zone could expand to 30,000 square kilometers, ten times larger than the Chernobyl zone, while contaminated areas could cover up to 2 million square kilometers. Radioactive fallout would likely spread beyond Ukraine to neighboring European countries, and could reach the Dnipro River as well as the Black and Azov Seas, triggering an environmental disaster.
Calls for de-occupation and international oversight
Ukrainian officials and nuclear experts insist that the plant must be fully de-occupied and returned under the control of Energoatom, Ukraine’s legitimate operator. Only then can professional maintenance, engineering work and the establishment of a demilitarized zone restore safety standards. They argue that the IAEA must apply greater pressure on Moscow to ensure such a transition.
The issue has also surfaced in high-level diplomacy. During talks earlier this year, Presidents Volodymyr Zelensky and Donald Trump discussed the future of the plant, including possible U.S. assistance in its de-occupation and management. U.S. Secretary of State Marco Rubio previously suggested that transferring control of the facility to the United States would provide the strongest safeguard for Ukraine’s energy infrastructure.