A third incident involving a nuclear power plant was registered in Ukraine on Tuesday. Should we fear a major disaster?
Chernobyl, Zaporizhzhya and now Kharkov… As the war in Ukraine entered its 13th day on Tuesday, a third incident involving a nuclear power plant in the country was confirmed by the Interfax agency.
After storming the Chernobyl nuclear power plant, the scene of the greatest nuclear disaster of the 20th century, and then bombing Europe’s largest nuclear power plant, in Zaporizhzhya, the Russian army therefore attacked an experimental nuclear installation in Kharkov.
Even if the authorities are reassuring until then, according to the Interfax agency, “the destruction of the nuclear installation and nuclear material storage facilities could lead to a large-scale environmental disaster”.
What are the real risks of these bombings? Are the Russians playing on western nerves by attacking nuclear sites? An article published on the scientific site Nature evaluates the risk of these very high symbolic targets.
Missile-resistant nuclear reactors?
According to Nature, “The Zaporizhzhya reactors have a modern design. Unlike the Chernobyl reactor, each reactor is enclosed in a steel pressure vessel, which in turn is housed in a massive reinforced concrete structure.”
In addition, “the factories also have several backup safety systems in place,” said Michael Bluck, director of the Center for Nuclear Engineering at Imperial College London. Catastrophic damage from a missile strike is unlikely. “If a missile gets lost, don’t worry. These are very robust constructions,” says Michael Buck.
Even in Chernobyl, the risk seems limited. “The hazardous material it contains is in the basement of the reactor building, protected by the remains of that building and the many tons of concrete poured over it,” writes Cheryl Rofer, a retired nuclear scientist. Molten fuel, which contains uranium and plutonium, seems out of reach.
Spent fuel ponds are the real danger… for Russia too
If nuclear reactors appear to be safe from attack, the scientific community is concerned about the basins where spent nuclear fuel is kept as it cools. Damage to these installations can cause a fire whose fumes can be extremely dangerous for local residents… but also for those further afield. And the scientists then remind … that “the Russians should bear in mind that the prevailing winds would carry a dangerous cloud … to Russia”.
A new Fukushima?
Still, the temptation could be to shut down power plants in the face of the threat of attacks. In Zaporizhzhya, for example, five of the six reactors have been shut down in recent days. Here, too, the consequences were not negligible. “The core of a reactor that has just been shut down needs to be actively cooled, which requires energy, which is normally taken from the grid. If active cooling of reactors suddenly stops, power plants like Zaporizhzhia could face a scenario similar to with that of the Fukushima Nuclear Power Plant in Japan, when the electricity went out after the earthquake and tsunami of March 11, 2011″.
A dramatic event that could also occur if damage were to occur to the systems that provide this essential cooling. And these elements are outside the containment structure of the reactor. They are therefore more vulnerable to missile attacks…