Reactor accident, radioactive waste… what are the risks of the Ukrainian power plant in Zaporijjia?

Reactor accident, radioactive waste… what are the risks of the Ukrainian power plant in Zaporijjia?

Published on: 08/20/2022 – 15:08

The international community is targeting Zaporizhia, where clashes between Russians and Ukrainians have been raging for weeks near Europe’s largest nuclear power plant. This tense situation poses several nuclear risks that all belligerents and their supporters wish to avoid. France 24 takes stock of the possible scenarios.

The Zaporizhia nuclear power plant has caused a stir in Ukraine in recent weeks. Fighting for this Russian-controlled site is taking place daily, and several international actors fear the situation will escalate. The last, Vladimir Putin, said Friday, August 19, he feared that the local bombings would result in a “major (nuclear) catastrophe that could result in radioactive contamination of vast areas.”

The Russian President and Emmanuel Macron have agreed to an inspection of the Zaporizhia power plant by the International Atomic Energy Agency (IAEA) “as soon as possible” to “assess the situation on the ground”. IAEA Director Rafael Grossi “welcomed” in a statement “recent statements showing that Ukraine and Russia support the IAEA’s goal of sending a mission”.

  • The main risk: a meltdown accident in a nuclear reactor

When it comes to a possible nuclear disaster, particularly in Ukraine, we naturally think of Chernobyl in 1986, which to date is the worst accident in history – at least thirty dead according to the United Nations Scientific Committee, but the casualties could be high harder if we count indirect deaths. Turkish President Recep Tayyip Erdogan, who traveled to Ukraine on August 18, was also alarmed by the threat of a “new Chernobyl” as “any potential damage to Zaporijjia would be suicide”.

According to Emmanuelle Galichet, teacher and researcher at the National Conservatory of Arts and Crafts (Cnam), “It is not possible to have an accident like that of Chernobyl at the Zaporijia power plant. There will be no accident with a radioactive cloud over Europe, as we have seen in the past”.

The main risk at the center of concern is one well known to nuclear energy experts: a meltdown accident in a nuclear reactor.

A diplomat told AFP on Friday that westerners are more concerned about maintaining the water cooling system for the Zaporizhia nuclear reactors than about exposure to a gunshot because they are designed to “survive the worst.”

“Reactor cores need to be cooled, and they need water and electricity to do that,” explains Bernard Laponche, a former nuclear engineer with the Atomic Energy Commission (CEA). The nuclear physicist fears not so much a bomb attack on the plant – “protected by a thick concrete dome” – but rather missiles that would hit next to it, be it on the power grid that supplies the plant or on the water pipes.

Without water and/or electricity, “there could be a meltdown like at Three Mile Island (in the United States in 1979) or in Fukushima (in Japan in 2011)”, specifies Bernard Laponche.

  • Radioactive waste, another nuclear risk

The other risk identified concerns nuclear waste at the Ukrainian site.

“There are two types of storage at the Zaporijjia plant,” explains Emmanuelle Galichet. “There’s the real spent fuel coming out of the reactor core: it’s stored in pools that are inside the containment building and are therefore fully protected. And there’s spent fuel out in the open.”

It is also the latter fuels that arouse fears. According to Bernard Laponche, “When a missile falls on this drop-off to Russia, Poland or Western Europe, there is either a fire or an explosion immediately.”

The nuclear physicist specifies that this cloud would depend on the amount of radioactive waste that would be set on fire and on the direction of the wind.

The teacher-researcher at Cnam puts into perspective the threat that this waste can pose, explaining that they are outdoors, “which means that their radioactivity has greatly decreased”. In the event of a bombardment, she therefore considers “the risk of radioactivity in the environment to be very unlikely”.

  • “Complicated” to disconnect Zaporizhia from the Ukrainian power grid

Another risk hanging over the nuclear power plant is that Zaporizhia will disappear from the Ukrainian power grid. UN Secretary-General Antonio Guterres, who visited Ukraine on August 19, urged Russia not to disconnect the power plant from the Ukrainian grid.

“The Ukrainian power grid was connected to the Soviet, then Russian grid. And almost on the day the war began in Ukraine (end of February, editor’s note) – because it had been prepared for a long time – the Ukrainian grid was connected to the European grid (…), which is very delicate,” explains Bernard Laponche.

Bringing the Zaporijjia power plant back onto the Russian power grid is therefore technically possible, but not easy, according to Emmanuelle Galichet: “Anything is possible if you want to interrupt the power supply, but these are industrial processes that are still very complex. The engineers on site know how to carry out such an industrial process, but there are always risks involved (including the risk of a power failure if the power is not cut off properly, ed.)”.

Finally, it seems possible to prevent these nuclear and electrical risks from becoming a reality if fighting in the Zaporijjia region ceases. Antonio Guterres therefore called for the “demilitarization of the plant”.

The nuclear physicist Bernard Laponche also wants this result and comes to the conclusion: “It is very surprising that when building these power plants in the 1970s to 1980s nobody ever considered the risk of war. We were then in a time of perpetual peace, and we recognize today that these are places of significant risk.”