Forty years ago, in late April 1986, US newspapers filled with frightening reports from Ukraine. The explosion after midnight of reactor number 4 at the Chernobyl nuclear power plant (NPP) trapped unaware residents of Prypiat in a hellish radioactive landscape. That Saturday morning, apartment residents sent their children outside to play soccer as usual, 16 weddings were held nearby, fishermen down at the river that served as coolant water for the station cast away in placid water. Heroic firemen who arrived on the scene were totally unprepared to extinguish smouldering radioactive graphite and fuel rods ejected from the reactor. All but one of them later died. Only 36 hours later did the authorities order the evacuation of the 50,000 residents from Prypiat, the support city built two miles from the reactors. Unbelievably, they ordered schoolchildren to march through radioactive breezes in the annual May Day parade the following Thursday in Kyiv.

The causes of the accident were already clear, as I wrote in a Boston Globe editorial that fateful week: the construction of reactors without containment; a design that led to explosive instabilities at low power; premature standardisation of components to cut costs; and the hubris of believing in the infallibility of technology, which was painfully revealed in the decision to call the massive assemblage of flammable graphite, uranium and plutonium a ‘nuclear park’. Mikhail Gorbachev later wrote that Chernobyl caused the collapse of the Soviet Union; he had celebrated his reforms of glasnost and perestroika, but it took him 18 days to address the nation publicly about the accident.

Chernobyl created new categories of radioactive people. Roughly 700,000 ‘liquidators’ were ordered into the battle to extinguish the reactor. They razed contaminated buildings, felled forests and bulldozed contaminated topsoil and irradiated materials. ‘Biorobots’ worked in one-minute shifts on the roof of the adjacent reactor, shovelling uranium fuel rods and steaming graphite into the gaping hole below. To subdue radiation, workers covered the destroyed reactor with a fragile concrete ‘Sarcophagus’ that was entombed again by a second covering in 2017. Russian invaders in Ukraine occupied Chernobyl briefly in 2022, stirring up radiation. They recently damaged the second covering with drones; it must be repaired. They shelled and occupied Ukraine’s Zaporizhzhia nuclear power plant, turning it into a dirty nuclear bomb waiting to happen.

Nuclear disasters destroy ecosystems. The authorities sent soldiers into the 1,000-square-mile Chernobyl exclusion zone to track, shoot and bury family pets, farm animals and wild creatures so they would not carry radiation on their fur into other towns. Much of the region will remain radioactive for centuries, and only several large mammals have recovered in population. Ultimately, the disaster led to between 5,000 to 50,000 excess cancer deaths, and untold cases of childhood leukaemia and thyroid cancer. At least 58,000 square miles of land – the size of Illinois or Georgia – were contaminated.

What does Chernobyl say about the future of nuclear energy? Chernobyl demonstrated explosively that many of the promises of the nuclear age may never be achieved: inherently safe reactors; nuclear-powered automobiles, locomotives and artificial hearts; an end to war over oil and gas, not to mention ‘energy too cheap to meter’. But industry moved ahead with belated attention to the potential for catastrophic accidents and to rapidly accumulating radioactive waste (RW). There are 450 reactors worldwide, with another 50 under construction. Over 400,000 tons of spent nuclear fuel occupies cooling pools and concrete casks awaiting final storage, and it grows by 11,000 tons annually, all at risk from terrorists. The Chernobyl exclusion zone alone holds 21,000 spent fuel assemblies, hundreds of tons of fuel within the Sarcophagus, and over five million gallons of other volatile RW.

Worldwide clean-up costs of the entire military and civilian nuclear enterprise have reached the trillions of dollars. The mitigation of Chernobyl, estimated at $700 billion, grows annually in the costs of fallow agricultural lands and abandoned factories. Japan’s Fukushima disaster in 2011 resulted from engineers’ determination to build a power station only 500 metres from the Pacific Ocean in an active seismic zone where it was inevitably inundated by a tsunami. The tsunami caused reactor meltdowns, required evacuation, and destroyed fisheries. The ongoing total costs of clean-up, lost livelihoods and property, and other energy sources have reached $500 billion. Meanwhile, Fukushima is releasing radioactive tritium from the cleanup into the Pacific Ocean.

The Chinese, French, Russian and American industries boldly claim that a nuclear ‘renaissance’ is upon us. Having buried Chernobyl and Fukushima in the deep fill of ‘exclusion zones’ they speak calmly of inherently safe Small Modular Reactors (SMRs); short construction horizons; non-carbon electricity production; and an immediate solution to hugely increasing electricity demand. The industries rely heavily on billions of dollars of government subsidies to make these claims. To accelerate construction in the US, the Trump administration has cut government safety oversight on nuclear power plants.

And so, the same questions remain from 1986: where will new stations be located? Who will pay for them? How much will they cost? Are SMRs safer and cheaper than the 450 reactors in operation at present? After all, only two have been built and several others were cancelled after cost estimates trebled even before construction began. What of a recent study in Plymouth, Massachusetts, showing that proximity to power plants is a cancer risk? How likely is another major accident?

In a word, hubris pervades the nuclear industry. The cost of construction for one reactor has reached $20 billion, waste is at risk of a terrorist attack, and clean-up lags decades and trillions of dollars behind. No accident will be named after a mishap at a wind or solar farm, but Chernobyl will be synonymous with technological failure for centuries to come.