This week, the International Atomic Energy Agency (IAEA) published a report on the results of its mission’s visit to the Zaporizhia NPP. And although the experts did not record any critical damage near the station that could lead to the release of radiation, they recommended that the shelling of the ZNPP be stopped immediately. The BBC says that the IAEA inspectors are most worried at the moment.

After the release of the report, shelling near the station continues and the situation has worsened even more.

Damage to objects

Zaporizhzhia NPP is the largest nuclear power plant in Europe. Since March 4, it has been under Russian occupation, and in the last month it has regularly come under shelling, which Russia and Ukraine blame each other for. However, the West is not inclined to believe Russia’s claims.

The IAEA mission, which arrived at the ZNPP on September 1, was at the station during one of these attacks.

According to the report, IAEA inspectors witnessed shelling in the vicinity of the ZNPP on September 3, due to which they even had to hide for a while in the basement of one of the station’s administrative buildings. Then experts recorded damage in various places on the territory of the ZNPP, in particular, in the immediate vicinity of the power units.

IAEA experts reported that as a result of that shelling, in addition to buildings not related to the storage of nuclear materials, the building of the special unit where fresh nuclear fuel and solid radioactive waste are stored was damaged.

On August 29, the occupying authorities of Energodar, where the plant is located, reported that a projectile had pierced the roof of the special unit of the ZANP. They traditionally blamed the armed forces of Ukraine for the shelling. The photo in which the inspectors examine the breached roof of the special block is also in the IAEA report.

At the same time, the damage to the building of the special unit does not threaten the spread of radiation, and the fresh nuclear fuel stored in the special unit is not radioactive, interviewed experts told the BBC.

“If this is a case in which fresh fuel is stored, then there is no radioactive danger. There is simply a lot of metal (uranium, zirconium, steel). It can be called a special case mainly because it is, after all, nuclear material – in the sense that it has to be under IAEA guarantees. This may require a certain regime of access, protection, etc. But there are no radioactive materials that would pose a danger,” explained Pavlo Podvig, a senior researcher at the UN Institute for Disarmament Research.

“It was reported everywhere that the fuel itself was not damaged. Therefore, there is nothing to worry about. But in this special case, fresh fuel is stored, not spent fuel. The uranium itself [in the fresh fuel] is radioactive, but in any case it is much less dangerous, than spent fuel,” said nuclear physicist and independent nuclear expert Dmytro Gorchakov.

Gorchakov noted that fresh fuel is delivered to special units in special steel containers – not as protected as concrete containers for spent fuel, but this is still an additional safety barrier.

“You can touch this fresh fuel with your hands in gloves, even I did that,” he added, “From a radiation point of view, it’s not scary. And if the containers are destroyed and the fresh fuel spills, it will be more dangerous from a chemical point of view. Dioxide uranium is toxic, and if inhaled, it will be dangerous more as a chemical compound than as a radioactive one.”

Dry spent fuel storage (SSF) at the ZNPP itself can become a potential source of radioactivity. Concrete containers that store spent fuel can be vulnerable to combat operations, although they have a large margin of strength.

But the IAEA report did not mention anything about the damage to the SSWAP. The inspectors only mentioned that as a result of the shelling on September 3, a container with a radiation control system, located next to the SSVYAP, was damaged.

Operation of power units and power transmission lines

As for the reactor power units themselves (there are six of them at the ZNPP), according to data at the end of August, only two of them were in operation. Moreover, at some point, both units automatically shut down due to shelling, but then they started working again.

On September 1, one of the two power units stopped again – the reasons for this are still unknown, according to the IAEA report. The next day, the power unit resumed work. On September 3, the working capacity of two working power units was reduced, and then one of them was stopped altogether.

At the moment, one power unit is operating at the ZNPP, according to the report. It continues to generate electricity, which the plant needs for cooling and other nuclear safety functions, the IAEA said.

However, the shutdown of the last reactor can happen at any moment.

Shutting down power units in itself is safe for the plant if it is connected to external power grids, says nuclear physicist Gorchakov: “It is much easier to maintain the safety of the reactor in a stopped state. But only if there is a connection with the external power system.”

It is for this reason that the IAEA inspectors were particularly concerned about the condition of power grid lines (LEM), which provide the ZNPP’s connection with the outside world and through which electricity flows.

“Of the damage recorded at the NPP, the damage to power lines was the closest to emergency scenarios,” Gorchakov notes.

The Zaporizhzhia NPP has four main LEMs and one standby one connecting the ZNPP with the nearby thermal power plant (TPP). Since the beginning of the war, three main LEMs have failed, and in early September the IAEA reported that the station had lost contact with the last, fourth main LEM.

At the same time, the reserve line connecting the ZNPP and TPP continues to work. On September 5, the Ukrainian side informed the IAEA that this backup line had to be temporarily disconnected to extinguish the fire, but the line itself was not damaged by it and then resumed work.

The state of ZNPP workers

The third point, which causes the greatest concern for IAEA inspectors, is the condition of the ZNPP workers who continue to work at the station, despite the Russian occupation.

The head of the IAEA, Raphael Grossi, said at a press conference after his visit to the ZNPP that ZNPP workers are forced to work under constant stress.

During the visit to the station, IAEA inspectors talked with the employees and in their report provided data on their numbers, according to which there is a shortage of personnel at the station.

In particular, ZNPP employees told the inspectors that in terms of “physical protection” at the station, 40% of the staff is lacking. As Gorchakov explained, it is about the guards: “It is clear that after [March 4] all the security of the station was taken over by the Russian troops. It is even surprising that [Ukrainian guards] remained. During the seizure of the Chornobyl NPP in March, they were all simply locked in basements “.

172 employees continue to work in the radiation safety sector of the ZNPP, which is 93% of the full-time workforce, the report says. Another 6% are on vacation or maternity leave, another 1% left Energodar.

The normal number of emergency response personnel is 1,230 people, but only 907 are currently working, the report said.

In the station’s fire brigade, 80 people continue to work – instead of the usual 150. To compensate for the lack of personnel, the firemen’s work schedule has been changed – instead of four shifts of 24 hours, they now work in three shifts of 48 hours.

“The fact that personnel are exposed to constant stress and a higher load during the operation of the ZNPP can lead to an increase in errors and consequences for nuclear safety,” the IAEA report says.

“Nobody knows where tomorrow will fly to”

In its work, the IAEA identifies “seven inseparable signs of nuclear safety” by which it assesses the state of various nuclear facilities. These are the physical integrity of the facilities, the serviceability of the equipment, the condition of the personnel, the external power supply, the logistics of fuel supply and transportation, the effectiveness of the radiation control systems and communication with the regulators.

In the case of ZNPP, all these seven components were found to be violated in one way or another, according to the IAEA report. The biggest fear of the inspectors was the physical damage to the station. That is why the main recommendation given by the inspectors in their report was a complete cessation of shelling.

The report details the effects of the shelling only on September 3, although the station was exposed to it for a month. “And where it will fly tomorrow – no one knows. Therefore, the main recommendation is to stop shelling. And agree on a safety zone, at least around the NPP site,” Gorchakov comments on the mission’s recommendations.

On September 8 and 9, shelling near the station continued. Energodar, the city of atomic workers, remains without electricity, which, as the head of the mission Grossi said, could negatively affect the safety of the ZNPP.