Forty years after the world's worst civilian nuclear disaster, Ukraine marked the anniversary of the Chernobyl explosion on Sunday with renewed urgency — not as a moment of distant historical reflection, but as an active warning about dangers that remain very much alive. On 26 April 1986, Reactor No. 4 at the Chernobyl nuclear power plant, in what was then Soviet Ukraine, exploded during a flawed safety test, releasing massive amounts of radioactive material across Europe and forcing the evacuation of some 116,000 people. Four decades on, the plant sits inside an active war zone.
Ukrainian President Volodymyr Zelenskyy used the anniversary to warn that Russia is "once again bringing the world to the brink of a man-made disaster." His concern centres on the New Safe Confinement — a $2.1 billion arch-shaped enclosure completed in 2019 over the ruins of Reactor No. 4 — which Ukrainian officials say was struck by a Russian drone in February 2025, causing structural damage and a fire. Moscow denied deliberately targeting the plant. Rafael Grossi, director general of the International Atomic Energy Agency (IAEA), visited Kyiv to echo those concerns, saying repairs to the damaged outer shell must begin immediately. The European Bank for Reconstruction and Development estimates those repairs will cost at least 500 million euros; Ukraine says partner nations have so far committed 130 million euros toward that total. Greenpeace has raised the alarm about a potential structural collapse of the confinement, a scenario the IAEA considers unlikely but does not fully dismiss.
The anniversary itself was shadowed by fresh bloodshed. Russian drone and missile strikes on the city of Dnipro, in central Ukraine, killed at least nine people. Separate strikes and counter-strikes across occupied territories and Russian border regions killed several more, with Ukrainian forces also hitting an oil refinery in Yaroslavl, deep inside Russia, sparking fires at a facility that processes 15 million tonnes of oil per year. The strikes illustrated the relentless tempo of a war now in its fifth year. Meanwhile, Russia's defence minister travelled to Pyongyang to meet North Korean leader Kim Jong Un and formalise closer military ties — North Korea having already sent thousands of troops and large weapons shipments to support Russia's campaign.
The human and historical weight of Chernobyl itself remains immense and contested. The Soviet Union officially counted 31 deaths from the immediate disaster, but estimates of long-term fatalities from radiation-related illness range from 4,000 to over 16,000. Roughly 600,000 Soviet citizens were mobilised for clean-up operations, many of whom were later stigmatised as "radioactive people" by their own communities. Former Soviet leader Mikhail Gorbachev later said the disaster was a key factor in the eventual collapse of the USSR in 1991, exposing the brittleness of a regime that tried desperately to suppress the truth. The plant still contains approximately four tonnes of highly contaminated nuclear residue at its core.
Why this matters extends well beyond Ukraine's borders. The damaged confinement structure sits atop the original hastily built 1986 sarcophagus, and any further deterioration could expose it to the elements. Separately, Europe's largest nuclear plant — Zaporizhzhia, in southern Ukraine — has been under Russian occupation since 2022 and has repeatedly lost external power connections due to fighting nearby, raising fears of a cooling failure. Grossi has said both situations represent extreme cases of human interference with nuclear safety. As the world debates a nuclear energy revival to address climate change — some 440 reactors currently operate globally — Chernobyl's anniversary serves as a stark reminder of what happens when geopolitics and nuclear infrastructure collide.