IAEA warns of prolonged diesel backup at Zaporizhzhia NPP
The International Atomic Energy Agency (IAEA) has warned that the diesel-powered cooling system at Ukraine’s Zaporizhzhia Nuclear Power Plant (NPP) could run out within about ten days if external power remains unavailable. The agency’s director general, Rafael Grossi, described the situation as the longest and most serious cooling challenge at Europe’s largest nuclear facility in the more than three and a half years of conflict.
Located in southern Ukraine and under Russian control since early in the war, the Zaporizhzhia NPP has six reactors, all of which have been shut down for safety and maintenance reasons. Even though the reactors are offline, cooling systems must be kept active to prevent overheating, a task currently being carried out by eight diesel generators. Grossi stressed that while cooling is ongoing, this is not a sustainable solution and does not meet the standards of nuclear safety in normal circumstances.
What happened and why power is still missing
According to Grossi, the last high‑voltage connection to the plant, which linked Zaporizhzhia to the Ukrainian grid, was severed on September 23. Since then, repair work has been hindered by ongoing fighting around the facility. The plant’s operators, who are under Moscow’s control, have limited ability to restore the link because access and security conditions remain unstable.
The IAEA chief noted that the diesel reserves in use at Zaporizhzhia are supposed to provide a temporary backstop, but the situation underscores a broader safety concern: without reliable external power, the plant’s cooling systems—critical for preventing overheating and potential radioactive release—are being kept alive by a single, non-sustainable power chain.
International reaction and what it means for safety
Grossi confirmed that he is in contact with both Moscow and Kyiv, urging all parties to restore a secure, sustained power supply to the site. He also called on the international community to intensify efforts to return Zaporizhzhia to a state where it can be safely managed within the Ukrainian energy system.
Ukraine’s energy ministry in Kyiv appealed to international partners to exert pressure on Russia to reestablish control of the plant and its connections to the Ukrainian grid. Greenpeace has accused Moscow of sabotaging the power lines in order to re-connect Zaporizhzhia to the Russian grid, a claim that has intensified the contested narrative around who is responsible for the ongoing outage. Russia has disputed these allegations, arguing that the situation is a casualty of the conflict and not a deliberate act of sabotage.
Why this matters for nuclear safety and regional stability
The Zaporizhzhia outage highlights the fragility of nuclear safety in war zones. Gas turbines and diesel generators, while capable of providing emergency cooling, are not designed to be permanent substitutes for an integrated grid connection. The IAEA’s assessment suggests that the longer a plant operates without stable external power, the greater the risk to cooling systems and, consequently, to the surrounding population and environment.
The episode comes amid a broader set of dynamics around energy security in Europe and the region: drone strikes and military activity have affected Russia’s oil infrastructure and power networks, and Western governments are weighing how best to deter escalation while protecting civilian energy supplies. The IAEA’s role is to monitor safety, coordinate information sharing, and press for transparent, verifiable steps to restore a safe operating condition at Zaporizhzhia without compromising treaty obligations and safety standards.
What happens next
Officials say the highest priority remains restoring an external power feed to the plant. Until then, maintaining robust on-site cooling through diesel power is essential but inherently precarious. The IAEA will continue to monitor the situation, provide technical guidance, and facilitate dialogue between parties to reach a durable resolution that keeps Zaporizhzhia safe and under Ukrainian control. The international community will likewise watch closely, balancing condemnations and warnings with practical steps to prevent a nuclear incident in the heart of Europe.
