For the first time ever, the Zaporizhia nuclear power plant, which has been repeatedly fired upon, has now been taken off the grid. The fear of a nuclear catastrophe in Europe’s largest nuclear power plant is increasing.
After an unprecedented emergency shutdown, the Zaporizhia nuclear power plant in southern Ukraine, which was occupied by Russian troops, is back online. The state power plant operator Enerhoatom announced that one of the two stopped blocks of the largest nuclear power plant in Europe had been reconnected to the Ukrainian power grid. The occupation authorities deployed by Russia had said so the day before.
But the tensions around the nuclear power plant continue to grow due to constant shelling – and with it the fear of a nuclear catastrophe. Some questions and answers about the situation and the dangers:
What exactly happened on Thursday? And how is the situation now?
According to the Ukrainian nuclear regulator, a 750-kilovolt high-voltage power line from the hydroelectric power plant in Nowa Kakhovka was damaged by Russian shelling. This led to blocks five and six being disconnected from the grid. The emergency shutdown system then took effect in both cases, it said. The Russian occupation authorities confirmed problems with the high-voltage line. An unspecified fire led to a short circuit.
After the emergency shutdown of the power plant units, the power failed in large parts of the Cherson and Zaporizhia regions occupied by Russia. After the fire was extinguished, one reactor went back online and work is being done to start up the second, the occupiers said. There were no reports of power supply problems in Ukrainian-controlled areas. According to Enerhoatom, the nuclear power plant is connected to the power system of Ukraine.
Is the safety of the nuclear power plant still guaranteed despite the fighting?
“A safe operation looks different,” says nuclear power plant expert Nikolaus Müllner from the Vienna University of Natural Resources and Life Sciences of the German Press Agency. If the military situation does not improve, it is only a matter of time before the facility is badly damaged and the damage can no longer be absorbed. “It’s playing with fire,” he says of what he sees as the irresponsible behavior of the Russian and Ukrainian armed forces.
According to the International Atomic Energy Agency (IAEA) in Vienna, all pillars of nuclear safety in Zaporizhia have at least been cracked. The IAEA is particularly concerned that the only remaining power line to the power plant, out of four, failed on Thursday. Because without external power, the nuclear power plant only has diesel generators to cool the reactor cores. Two lines should now be back in operation.
What is an emergency shutdown of a nuclear power plant and how risky is it?
In the event of an emergency shutdown, the nuclear chain reaction is stopped and the temperature in the reactor is rapidly reduced. “That’s not really a problem,” says Müllner. Emergency shutdowns would also occur again and again at other nuclear power plants. Such an action puts a little more strain on the plant’s systems than a slower routine maintenance shutdown, but is not dangerous. Russia and Ukraine are now expecting an IAEA mission at the site in Enerhodar so that the experts can get an idea of the situation soon.
What could an IAEA mission do on site at the nuclear power plant?
IAEA chief Rafael Grossi wants to lead the mission personally “to help stabilize security there,” as he wrote in his most recent situation report on Ukraine. IAEA experts want to investigate damage and security systems on site themselves, because the information from Kyiv and Moscow is often contradictory. In addition, the IAEA would like to get an idea of the working conditions of the Ukrainian nuclear plant employees who have been working under the control of the Russian occupiers for months. In addition, IAEA inspectors want to ensure that all nuclear material is still in place.
What else stands in the way of an IAEA mission?
It must be ensured that the IAEA team is not shot at, as Grossi told the France24 broadcaster this week. Both Kyiv and Moscow have repeatedly stressed their support for the mission in principle; however, Grossi has not yet been able to announce that he has received the necessary security assurances. In addition, there are still talks about what exactly the IAEA will do in the nuclear power plant, Grossi said.
What if the power plant is permanently shut down?
The main problem is keeping the reactors cool as the fuel rods continue to produce heat even after they have been shut down. According to Ukrainian information, the connection to the nearby thermal power plant is intact. This would power the cooling systems. If the external power supply fails, diesel generators go into operation. According to Enerhoatom boss Petro Kotin, diesel should be available on site for at least ten days. However, there are no guarantees because the continuous operation of the generators has never been tested.
The loss of output from the two power plant blocks can currently be partially coped with by the Ukrainian system. Their net output is 1900 megawatts. According to the network operator Ukrenerho, the country also exported more than 600 megawatts of electricity to neighboring western countries on Thursday. On Friday, exports even rose to 653 megawatts. In winter, however, the country’s electricity demand will increase. The failure of the nuclear power plant could overload the grid and thus lead to major power outages.
How great is the nuclear danger?
Russia and Ukraine have warned that a potential nuclear disaster could be far worse than that of the 1986 Chernobyl nuclear power plant. There is also an interim storage facility on the power plant site. According to Enerhoatom, these are currently 174 containers, each with 24 spent fuel assemblies, stored in the open air. Direct artillery hits could therefore create something like a “dirty atomic bomb”.
Against this background, Russia rejects demands from the international community to hand over the nuclear power plant to Ukraine. Moscow cited security concerns that Ukraine could not guarantee that the radioactive material would not fall into the wrong hands. In the event of a catastrophe, Russian areas in particular would be massively irradiated.
What could be behind the problems around the nuclear power plant?
The state-owned Ukrainian nuclear power plant operator Enerhoatom has repeatedly accused the Russian occupiers of preparing to connect the areas to the Russian power grid. The shelling of high-voltage lines is a diversionary tactic to first de-energize the occupied areas and then gradually synchronize them with the Russian grid. After connection to the Russian grid, the capacities of the southern Ukrainian power plants would be lacking in the Ukrainian grid and cause massive problems with the electricity supply there.
So far in July, the Russian occupiers have only repaired the high-voltage lines to the Black Sea peninsula of Crimea that Ukraine blew up in 2015. Crimea, annexed by Russia in 2014, was later connected to the Russian grid via underwater lines. After the emergency shutdown of the reactors on Thursday, there were initially no indications of synchronization with the Russian network in Crimea.