A building at the Zaporizhia (or Zaporizhzhia) nuclear plant, located in the Ukrainian city of Energodar, caught fire for several hours on Friday, March 4. This, after being attacked by the Russian Army, which later took control of the largest nuclear power plant in Europe.
The Russian attack sparked concern across the European continent due to the danger of a potential atomic catastrophe. In fact, the president of Ukraine, Volodimir Zelensky, warned that if an explosion occurs “it will be the end of everything. The end of Europe”.
The president emphasized that the Russian troops had fired knowing of the nuclear facility.“These are tanks equipped with thermal cameras, so they know where they are shooting”, he specified.
For his part, Ukraine’s Foreign Minister Dmytro Kuleba warned Europe that an explosion at such a nuclear power plant could be 10 times worse than what happened in 1986 at Chernobyl.
The Russian attack on the Zaporizhia nuclear plant caused panic among the population. Reports of an “imminent nuclear threat” or that the nuclear plant is well protected and cannot be blown up by bombing, flooded social media.
Likewise, the fact that Russian troops now have two nuclear plants in their possession, with which they can threaten not only Ukraine but also the whole of Europe, has caused fear in the world.
The International Atomic Energy Agency (IAEA) reported that the fire did not affect the main equipment of the nuclear power plant. The radiation level is normal.
But, what is the real danger that the Zaporizhia nuclear power plant has of an explosion in its facilities?
Ukraine, like probably no other country in the world, knows what a nuclear catastrophe is. However, scientists quoted by the Ukrainian media outlet HB maintain that there are still no direct reasons for the panic.
What is the Zaporizhia nuclear power plant like?
Equipped with six WWER-1000 type reactors and total power of 6,000 MW, it is the main supplier of electricity in Ukraine with a generation of between 40,000 and 42,000 million kWh per year, which represents a fifth of the country’s production and half of all output from the four Ukrainian nuclear power plants.
All Zaporizhia reactors are water and double circuit. They are made according to the most secure serial technology that exists at the moment.
The primary water, which comes into contact with radioactive elements, remains inside the sealed casing. The water from the second circuit, which feeds the turbines, is never combined (and in principle cannot be mixed) with the water from the first circuit. There is only heat exchange between them.
This is a key difference from the Chernobyl nuclear power plant with its single circuit reactors without a sealed casing.
According to a Ukrainian expert, the sealed shell is a concrete cube measuring 50 by 60 meters. The thickness of the walls is about one meter of strong concrete. The reactor itself is made of the highest quality steel and has dimensions of about 5 by 6 meters and is situated in the center of this cube.
In fact, it is a compact device with a very high level of protection.
Impossible to blow up the reactor according to the experts
Modern nuclear fuel has a low level of enrichment and the energy management system has multi-level protection systems. It uses not only control rods (which many have heard of after the Chernobyl accident), but also a solution of boric acid, which is injected into the primary circuit water, if necessary.
Safety systems are set to shut down the reactor in any kind of emergency and to allow a long time before the reactor can be restarted. This is done so that the staff can eliminate all possible causes of previous emergencies.
The thermal inertia of the reactors of modern nuclear power plants is much lower than that of old plants, such as Chernobyl. The reactor cools down much faster after stopping.
Is it possible to make an atomic bomb from a reactor?
The worst that can happen if the reactor’s pumps and ancillary equipment are physically shut down is a nuclear fuel leak. But it will only be collected in a special tray located under the reactor. That is, there will be no explosion in such a scenario.
Fears of a nuclear explosion or serious radiation leak due to the bombing of nuclear power plants also appear unfounded. The thickness of the concrete block is such that it is very difficult to break. One or two hits will not suffice. After that, it is possible that only the second circuit in which the water is radioactive will be damaged.
Damage to the equipment around the unit will also not lead to a nuclear catastrophe, as it can only cause the turbine and the unit to shut down.
However, it should be noted that there is an alternative view: the reactor can overheat during prolonged operation without proper cooling. And this is a likely catastrophe scenario; however, at this time we do not have an understanding of how long that process may take and what kind of catastrophe may occur as a result.
In any case, since the Zaporizhia nuclear power plant is the largest in Europe, any combat near such a large nuclear facility is associated with risks.
In 2000, the Zaporizhia NPP was recognized as one of the three best nuclear power plants in the world, which fully meets the requirements of the IAEA.