An electrical outage has disrupted cooling systems at Ukraine's Chernobyl Nuclear Power Plant, raising concerns about potential radiation risks. However, experts assess the meltdown danger as extremely low due to the aged state of the stored fuel. The International Atomic Energy Agency is monitoring the situation closely.
The Chernobyl Nuclear Power Plant, site of the 1986 disaster, experienced a power outage that halted its spent fuel cooling systems. This disruption stems from Russian military strikes on Ukrainian electrical substations, as reported by the International Atomic Energy Agency (IAEA). IAEA Director General Rafael Grossi stated on X: “The IAEA is actively following developments in order to assess impact on nuclear safety.”
Spent nuclear fuel, removed from the reactors years ago, continues to generate heat from radioactive decay. Normally stored in a cooling pond replenished with cold water, the fuel now faces rising temperatures without electricity to circulate the water. Evaporation could accelerate, but the fuel's age mitigates the threat. Reactors at the site were progressively decommissioned: reactor 4 after its 1986 explosion, reactor 2 in 1991, reactor 1 in 1996, and reactor 3 in 2000.
Paul Cosgrove, a nuclear expert at the University of Cambridge, explained the cooling necessity: “When the fuel comes out of a reactor, it will be hot for a while, because there will be fission products and there will be radioactive and giving off gammas and betas and alphas – just emitting energy, which needs to be removed, otherwise it will eventually melt.” He added that a 2022 regulatory inspection deemed overheating risk low, noting: “This fuel has been sat in there for 20 years, so it will have decayed. More and more of that energy will be gone.”
Ian Farnan, also at Cambridge, acknowledged the concern: “It is always a worry when a nuclear site loses power, but worry about nuclear risks is often several orders of magnitude above the risks associated with other events with similar consequences.” The current risk is lower than during similar outages in 2022.
This incident fits a pattern of threats to Ukrainian nuclear sites since Russia's full-scale invasion, including the occupation of Chernobyl, control of Zaporizhzhia Nuclear Power Plant, and a drone strike on Chernobyl's New Safe Confinement structure in February 2023. Power supplies across Ukraine, including Chernobyl, have fluctuated amid escalating infrastructure attacks.
