Zaporizhia
Ukrainian nuclear power plants: Risks in war that are difficult to calculate
IAEA Director-General Rafael Mariano Grossi addresses the situation at the Zaporizhia nuclear power plant in Ukraine at a press conference in March. photo
© Lisa Leutner/AP/dpa
Europe’s largest nuclear power plant has come under fire in Ukraine. Such systems are protected against many dangers worldwide. In a war, however, there are other risks that are difficult to calculate.
The hostilities surrounding Ukraine’s Zaporizhia nuclear power plant are ringing international alarm bells. Although no radioactivity was released in Europe’s largest nuclear power plant, the head of the International Atomic Energy Agency (IAEA), Rafael Grossi, sees the “very real danger of a nuclear catastrophe” in the war zone.
As early as 1986, a devastating nuclear accident occurred in Ukraine, which is considered to be the largest nuclear disaster in the civil use of nuclear power. A block of the then Soviet Chernobyl power plant exploded. Irradiated areas around the kiln were closed. There were thousands dead and injured. Tens of thousands of people were forcibly relocated. The temporary occupation of the decommissioned nuclear power plant at the start of the Russian invasion briefly raised concerns about the safety of nuclear waste on site. How safe are the other Ukrainian nuclear power plants?
What is the situation in Zaporizhia? Who is in control there?
According to statements by Russians and Ukrainians, the power plant site has been shot at several times in the past few days. Moscow and Kyiv blame each other. The allegations on both sides cannot be verified independently – also because no IAEA experts have yet been admitted to the territory occupied by Russia. The critical infrastructure of the power plant is said to remain intact, but the shelling not only potentially endangers the reactors, but also the power plant’s own nuclear waste interim storage facility.
How is the staff in the occupied nuclear power plant?
At the power plant, Ukrainian personnel continued to work five months after it was captured by Russian troops. However, according to Ukrainian information, these employees are supervised by employees of the Russian nuclear company Rosatom. Up to 500 Russian soldiers are also said to be staying on the power plant site and using the building as a warehouse for military technology. Ukrainian forces are stationed across a nearby reservoir. IAEA chief Grossi recently warned that Russian armed forces should not put pressure on personnel. From the point of view of the IAEA, the constant stress also increases the risk of operating errors that could endanger the safety of the nuclear vehicle. Can such facilities withstand military attacks?
“Basically, military attacks are not part of the design of nuclear power plants,” says risk researcher Nikolaus Müllner from the University of Natural Resources and Life Sciences in Vienna. Nuclear power plants are built to withstand natural disasters, plane crashes or terrorist attacks. Protection against targeted military destruction is hardly possible. However, the scientist, who is currently investigating the dangers for Ukrainian nuclear power plants, assumes that an accidental shelling with conventional weapons, as it probably took place in Zaporizhia, will not result in fatal damage to the reactor containment. Can safety deficiencies arise even without damage to the reactor?
According to Müllner, the destruction of the system’s external power supply could, in the worst case, lead to a core meltdown. If the on-site emergency generators remain intact, the reactors can be cooled for a few more days. If these aggregates or the diesel supplies for their operation are also destroyed, according to Müllner there are a maximum of 15 hours before the nuclear accident. Another danger is damage to steam lines. In this case, too, the cooling system is at risk. The IAEA also warns that nuclear safety systems could be destroyed and that action plans in the event of a nuclear accident in combat are no longer effective. Since the shelling in Zaporizhia, some radiation measuring devices have already been defective.
What is the security situation of the other nuclear power plants in Ukraine?
The other three active Ukrainian nuclear power plants are currently not threatened by direct hostilities. During their advance in March, Russian troops came the closest at almost 100 kilometers to the power plant in the Mykolaiv region, also in southern Ukraine. After their retreat, however, they are now about 140 kilometers away. The Rivne power plant in northwestern Ukraine is potentially at risk from Russian shelling from Belarusian territory. It is just under 40 miles from the border with authoritarian Belarus, which is an ally of Russia. Rockets have been fired at Ukraine from there several times in recent months.
How would a failure of the Zaporizhia nuclear power plant affect Ukraine’s electricity supply?
According to Ukrainian information, three of the six reactors with a net output of 2,850 megawatts were in operation until the weekend’s shelling. One of the blocks was then shut down as part of an emergency shutdown. Nevertheless, Ukraine continued to export 660 megawatts to Poland, Romania, Moldova and Slovakia on Monday. Due to the economic slump of 30 to 50 percent caused by the war, the Ukrainian demand for electricity has fallen massively. The country could therefore cope with a complete failure in the short term, at least in the summer. For the heating season in winter, however, an increased demand for electricity can be assumed. In 2021, Ukraine’s nuclear power plants provided more than half of the electricity supply.