What is the significance of this power plant?
The Zaporizhzhia nuclear power plant, built between 1984 and 1995, is the largest nuclear power plant in Europe and the ninth largest in the world. It has six reactors, each generating 950MW, and a total output of 5,700MW, enough energy for roughly 4m homes.
In normal times it produces one-fifth of Ukraine’s electricity and almost half the energy generated by the country’s nuclear power facilities.
The plant is located in south-east Ukraine in Enerhodar on the banks of the Kakhovka reservoir on the Dnieper river. It is about 200km from the contested Donbas region and 550km south-east of Kyiv.
What happened on Friday morning?
A fire broke out in a training building outside the plant in the early hours of Friday, after being shelled by Russian forces, Ukrainian authorities said.
The first report came from an employee at the plant, who posted on Telegram that Russian forces had fired on the facility and there was “a real threat of nuclear danger at the largest nuclear power plant in Europe”.
Ukraine’s foreign minister confirmed the reports at 2.30am, tweeting that the Russian army was “firing from all sides upon Zaporizhzhia NPP, the largest nuclear power plant in Europe. Fire has already broken out.” He called for an immediate ceasefire to allow firefighters to control the blaze.
A short time later, the Ukrainian State Emergency Service reported that radiation at the plant was “within normal limits” and the fire conditions at the plant were “normal”. It reported that the fire was in a building outside the power plant.
They later reported that the third power unit at the plant was disconnected at 2.26am, leaving just one of the plant’s six units, unit four, still operating.
Early reports of the incident at the power plant sent financial markets in Asia spiraling, with stocks tumbling and oil prices surging further.
Is there a radiation threat?
Ukrainian authorities on Friday morning said the facility was secured and “nuclear safety is now guaranteed”.
Earlier, the International Atomic Energy Agency said the Ukraine regulator told the agency that there was “no change reported in radiation levels at the Zaporizhzhia nuclear power plant site”.
The US also said their latest information showed no indication of elevated radiation levels at the plant. The US energy secretary, Jennifer Granholm, said the reactors “are protected by robust containment structures and reactors are being safely shut down”.
Russia has already captured the defunct Chernobyl plant, 100km north of Kyiv. Some analysts noted the Zaporizhzhia plant is of a different and safer type to Chernobyl, which was the site of the world’s worst nuclear disaster in 1986.
The chances of explosion, nuclear meltdown or radioactive release are low, said Tony Irwin, an honorary associate professor at the Australian National University.
Irwin, who operated nuclear power plants in the UK for three decades, is a former manager of the open-pool Australian lightwater (OPAL) reactor, Australia’s only nuclear reactor.
He said the pressurized water reactors were “a lot safer” than the reactors at Chernobyl, and did not appear to be damaged yet. The reactors have large concrete containment and built-in fire protection systems, he said, adding: “Obviously, it’s not a good idea if you start shooting massive missiles at reactors,” he said. “The PWR type is a much safer sort of reactor, because it’s a two-circuit design reactor. The water that keeps the reactor cool is on a separate circuit to the second one, which actually supplies the power to the turbine and the outside.”
“These reactors have back-up emergency cooling systems as well. In addition to the normal reactor cooling, they’ve got a passive system, they’ve got high-pressure injection systems, they’ve got low-pressure injection systems.”