New explosions over the weekend at Ukraine’s Russian-controlled Zaporizhia nuclear power plant have renewed fears of an accident at Europe’s largest nuclear power plant.
Here’s a look at the state of the plant in southern Ukraine and the risks of renewed shelling and pressure on staff.
– What is the condition of the system? –
Moscow took control of the compound on March 4, shortly after beginning its invasion.
Since early August, the situation at the plant has deteriorated, with Moscow and Kyiv blaming each other for the shelling around the plant.
This weekend, the International Atomic Energy Agency (IAEA) reported around a dozen strikes.
“Whoever it is, stop this madness!” said IAEA chief Rafael Grossi.
Grossi, who has warned of the possibility of a “nuclear catastrophe,” has held talks with Moscow and Kyiv to set up a security zone around the power plant. The Vienna-based UN nuclear watchdog has several experts on site.
Describing the attacks as “deliberate, targeted,” he said the recent shelling came “dangerously close to… key nuclear safety and security systems at the facility… We’re talking meters, not kilometers.”
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Among the damaged sites are a radioactive waste building and a storage building, the IAEA said, adding that radiation levels at the site remain normal.
– What are the risks of strikes? –
“A direct impact on the reactors, on associated facilities, especially on the spent fuel assemblies that contain the spent fuel assemblies, could have very serious consequences,” Grossi warned in September.
The containment of each of the six Russian-designed reactors is “quite robust,” Tariq Rauf, a former IAEA official, told AFP.
He added that after the 2011 Fukushima nuclear disaster in Japan, “many remedial actions and replacement shipments” had been taken.
“But of course none of these things are designed to survive a war,” he warned.
The other risk is a prolonged power outage.
Normally, the plant’s systems are supplied by four 750-kilovolt lines. A neighboring combined heat and power plant can supply electricity via backup lines.
Shelling has repeatedly damaged the lines, necessitating repairs by Ukrainian engineers and at times forcing the operator, Ukrainian Energoatom, to temporarily resort to generators.
The facility has 20 emergency diesel generators, which are supplied for around 15 days of operation.
– Could a Fukushima-style scenario be upon us? –
Electricity is essential to run the pumps that keep the water circulating and the fuel constantly cooled in the reactor cores and storage pools.
According to the French Institute for Radiation Protection and Nuclear Safety (IRSN), “a prolonged total blackout of the power supply would lead to core meltdown accidents and radioactive releases into the environment”.
This would be similar to Fukushima in 2011, but there a deadly tsunami knocked out the emergency generators, causing a “very rapid blackout,” IRSN’s Karine Herviou said.
In addition, “these are not the same models: the volume in the containment enclosures is larger, so any increase in pressure would be slower,” she told AFP.
Zaporizhia’s six reactors are all currently in shutdown mode. In the event of an accident, “the consequences are less serious” the longer a unit is idle, Herviou added.
Before the start of the war, the power plant provided 20 percent of Ukraine’s electricity.
– What is the risk for staff under pressure? –
Energoatom boss Petro Kotin told AFP in September that Russian forces had tortured nuclear power plant workers and killed at least two people. He has also said that factory workers have been kidnapped “on a regular basis”.
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Russian troops have also taken over the plant’s emergency response center, which Herviou says raises questions about how well a critical situation would be handled.
“This center is essential so that the Ukrainian teams can monitor the condition of the facilities, take the necessary measures to limit the consequences of an accident, call for external reinforcements and alert the population,” Herviou told AFP.
The IAEA has repeatedly denounced working conditions, calling them “increasingly difficult and exhausting” over the past month and warning that this too could risk a nuclear accident.