It is emphasized that a major problem in the war in Ukraine was the first ever emergency shutdown of all four Ukrainian nuclear power plants.

As a result of the Russian strikes on November 23, the main power supply of four nuclear power plants in Ukraine disappeared – they went into emergency mode. Due to this situation, fears are growing in the world that Russia’s constant attacks on the Ukrainian energy system threaten the safety of nuclear power plants.

As The Guardian writes, Europe’s largest Zaporizhzhya nuclear power plant, which Russian troops seized after the start of a full-scale invasion back in March 2022, has been offline since September amid frequent shelling of the area around it. Three other Ukrainian nuclear power plants – Rivne, Yuzhno-Ukrainska and Khmelnytska – were not direct targets of the latest Russian missile strikes, but their safety was threatened.

“The complete and simultaneous loss of external sources of electricity for Ukrainian nuclear power plants shows that the situation with nuclear safety in the country is becoming increasingly shaky, complex and potentially dangerous,” said IAEA Director General Rafael Mariano Grossi.

In turn, Petro Kotin, president of Energoatom NAEC, noted: “For all 40 years of work of the Ukrainian nuclear industry, nothing like this has happened.”

He emphasized that against the background of the explosion at the Chornobyl NPP in 1986, all Ukrainian nuclear power plants are equipped with several levels of protection so that such a disaster does not happen again.

During the November 23rd attack, the reactors immediately began to isolate and the diesel generators were activated to circulate water through the cooling pools where the spent fuel is stored.

However, repeated attacks on Ukraine’s power system, which are likely to lead to further shutdowns, will put stress on all plant components – from the core to steam turbines and generators – by rapidly shrinking and then expanding again during restarts.

Oleg Korikov, chief nuclear safety inspector of Ukraine, noted that every time there was an emergency shutdown, the risks increased many times.

“Any use of the scram system can cause an accident. This shutdown process increases the likelihood of equipment failure or personnel error,” Korikov said.

Diesel generators are known to be able to support cooling and other safety systems, but they do not produce enough power to restart a power plant. Once the entire power system shuts down, this process is called a “black start,” and the longer the outage lasts, the more severe it becomes.

The situation is complicated by the fact that the shutdown of the nuclear reactor is carried out by the xenon isotope in the fuel rods, which absorbs neutrons, slowing down fission and making it difficult to restore it. Therefore, stopping and restarting requires considerable skills on the part of Ukrainian personnel of power plants and the pressure on them is significant, especially on ZANP workers who work under the occupation of the Russian military.

After Russia announced that the ZANP was part of Russian territory and therefore under the supervision of Rosatom, some experts saw in this change of attitude that the Russian occupiers might intend to withdraw from the ZANP.

The President of NAEK Energoatom also added that the second sign that they can develop plans in case of departure is systematic looting.

“They start stealing everything they see and packed their bags to get out of there,” he said, noting that there was no clarity about the Russians’ intentions.

But a former ZANP worker who spoke with current workers said they saw no signs of the Russians leaving. On the contrary, they say, the soldiers at the factory were preparing for winter by moving their sleeping quarters into the dining room.

Rafael Grossi has been trying for months to agree on the creation of a “security zone” around the nuclear power plant where shelling would be prohibited, but Ukraine insists that such a zone must be completely demilitarized.

According to Kotin, it is not yet known whether explosive materials are stored in the turbine halls. But the militarization of the Zaporizhzhia NPP increases the constant pressure on the personnel, who are forced to keep the two reactors in the mode of “hot shutdown” in order to provide a certain amount of electricity for the needs of the plant and the city of Energodar.

“When you have armed men breathing down your neck in the control room, it’s just an incredibly dangerous situation. If you have three nuclear power plants with no external power supply and you can’t restart them because the grid is down, it’s like three huge time bombs. All of this together means that we are talking about the most dangerous moment for nuclear security,” said Mariana Boujerin, a senior research associate at Harvard University’s project on atomic control.

Nuclear threat in Ukraine: Russian attacks on nuclear power plants

Since October 10, Russian attacks on the objects of critical infrastructure of Ukraine have not stopped. The occupiers are hitting power stations, hydropower and heat generation facilities. An emergency power outage began across the country.

Russia is trying to stop Ukrainian nuclear power plants After Russia attacked Ukraine’s energy system on November 23, the Zaporizhzhia nuclear power plant went into full blackout mode. Three more Ukrainian nuclear power plants were shut down. The Ministry of Energy of Ukraine announced that a blackout had begun in the entire energy system of the country.