Fire breaks out at nuclear power plant in Ukraine

As a fire reported by Ukrainian officials continues at the Zaporizhzhia nuclear power plant, nuclear experts answered some of the most urgent questions:

Are there systems in the plant that can automatically fight the fire? Yes, but they don’t fight all fires, said nuclear policy expert and Harvard professor Graham Allison. And not all fires at a power plant can have “catastrophic consequences.” It depends on where the fire is — the biggest concern is if the blaze reaches a reactor’s cooling pits, which could cause a meltdown of the reactor.

What could happen if a reactor melts down? If a fire, missile strike or other type of attack disrupts the nuclear reactor’s cooling structure, it won’t be able to cool itself — causing the fuel inside to overheat and melt down, releasing large amounts of radioactivity, said James Acton, co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace.

The most recent and severe examples include the 2011 Fukushima nuclear disaster in Japan, and the 1986 Chernobyl disaster in Soviet Ukraine.

How likely is this? It’s hard to say because there’s still much we don’t know, several experts agreed — most importantly, where the fire is located, whether it’s even near the reactors or in a different part of the nuclear power complex, whether all the reactors are working — all things that could influence the severity of a disaster, if one occurs.

Why is the power plant coming under attack? Russian troops appear to be trying to seal off a nearby river and encircle Ukrainian forces, a classic maneuver, said retired US Army Gen. Wesley Clark — and the power plant is “right in the way.” The plant is also a “key strategic asset,” providing much of Ukraine’s power, he added: “Take that offline, the grid is at least temporarily destabilized. You’re cutting the ability of Ukrainians to be able to handle communications to a lot of other things.”