Patricia Fernández, nuclear safety inspector: “Zaporiyia will not be another Chernobyl, it is remotely impossible”

The fighting between Russia and Ukraine around the Zaporizhia nuclear power plant has created an “unsustainable” situation. The International Atomic Energy Agency (IAEA) has warned this after visiting the plant, which has been occupied by Russian troops since March 2022. “The bombing of the plant and its surroundings must stop immediately to avoid causing further damage to the facilities,” insists the IAEA. In everyone’s mind is the fear of a nuclear accident in the middle of Europe. The IAEA has been calling for “the establishment of a nuclear security and protection zone” around the plant for some time, and this Saturday the Atomic Energy Agency of Ukraine, Energoatom, reported that the only remaining reactor in Zaporizhia had ceased operations. Ukraine maintains that the disconnection of the plant from the Ukrainian network is the result of the constant bombing in the vicinity of the plant, which had forced the plant to operate in island mode, so that the only active reactor – number six — it was limited to supplying energy for the facilities themselves. For this reason, Energoatom explained in its Telegram profile, after the restoration of one of the external lines on Saturday night, the decision was made to stop and cool down the reactor, claiming that it is the safest to avoid a possible disaster. But, what is the real risk of leaks or accidents? Patricia Fernández, nuclear installations inspector for the Nuclear Safety Council (an independent public body), explains in this interview that a misfortune can happen, but that it is unlikely to be serious: “This is not going to be another Chernobyl,” she asserts. she asks her. Do we have to fear that there may be a serious accident due to the fighting around the Zaporizhia nuclear power plant? Answer. Accidents can happen, but the plants are prepared to withstand situations like the ones that are taking place now, such as fires, explosions nearby or loss of external power supply: They have redundant safety systems that are capable of preventing accidents from occurring, and if produce mitigate the consequences. They are very safe. The probability of an accident in the current situation of the plant is possible, but it is very low. The core of the reactor is inside a one and a half meter thick concrete building reinforced with rebar that would withstand even the impact of an airplaneP. What are these redundant security systems? A. The most serious thing that is happening now in Zaporizhia is that, due to the fighting, there are power cuts. And we must bear in mind that the electrical system is what guarantees the detention, the safe shutdown of the reactor, that is why they are so important. Well, to make up for these supply cuts, the plant has emergency generators that are capable of providing the necessary electricity so that the security systems can perform their function: maintain the cooling of the nuclear fuel. Specifically, the one in Zaporizhia has, for each of the units, which are six, three diesel generators capable of being active autonomously for ten days. Only one of these generators guarantees the necessary cooling. In this way, since there are three, safety operation would be guaranteed for 30 days, without any external power supply. If the power supply failed, the three autonomous generators of each of the Zaporiya units could maintain refrigeration for 30 daysP. And the core of the reactor, could there be leaks, or a collapse? A. The core of the reactor is inside what is called a containment building. It is a concrete construction reinforced with rebar, one and a half meters thick. This building is designed to withstand very high pressures inside and external attacks. The containment protects against explosions and terrorist attacks, for example it withstands the impact of an airplane. And yes, a bomb could damage this containment building, but it would not be destroyed. Reaching the reactor… I think the possibility is very, very remote. Q. Are they systems like the ones Chernobyl had? A. No, they are much safer. The ghost of Chernobyl, which some voices have resurrected, I don’t see as likely. This is not going to be another Chernobyl. It’s not even remotely possible. Chernobyl did not have this containment building, for example, the explosions of steam or hydrogen, it was blown up. That’s what containment is designed for. That is, in the unlikely event that there was no way to cool the fuel, which is already very remote, the containment is designed to withstand the release of products to the outside. In addition, there is another layer of security, because after the accident of the Fukushima plant all plants installed filtered vents. These systems allow that if the fuel is not cooled, and the temperature begins to rise too much, it could be vented to the outside and the pressure would be relieved. In this way, as it is filtered, it would enter the air but no radioactive material would come out, or the amount that would come out would be minimal.