At 9am on 24 February, Vyacheslav Yakushev and 89 of his colleagues were supposed to end their shifts at the Chernobyl power plant and go home.

Most employees live in the nearby purpose-built town of Slavutych, and travel to work by train – crossing Ukraine’s border with Belarus twice in the process. The site of the most damaging nuclear disaster in history is just a few kilometres from a section of Ukraine’s northern border with Belarus, which sticks out into Ukraine like a pocket.

But Sasha Kovalenko, the engineer who was meant to take over Yakushev’s shift at 7am, had not arrived. In fact, Kovalenko was still waiting for his train: as it was revealed later, the line had been severed when a bridge was blown up earlier that morning.

Supervisor Valentyn Geiko announced that there would be no shift change. A full-scale war had begun, he explained, and the plant must remain on high alert. Soon after, columns of Russian armoured vehicles began to appear on the plant’s CCTV system.

“There was a feeling that what was happening was unreal. ‘Guys, are you serious? Do you understand where you are going?’” Yakushev remembers thinking about the Russian soldiers.

Yakushev finally returned home to his wife and daughter 26 days later, on 20 March. He had spent more than 600 hours at the station.

Over the past two months, Ukrainian news outlet Graty has pieced together how the Russian occupation of Chernobyl went ahead. In partnership with Graty, openDemocracy is publishing an abridged translation of their work.

Today, Ukrainian law enforcement is investigating how much property the Russian forces stole from the Chernobyl exclusion zone (current estimates put it at 26m hryvnia, or £717,000) and who is responsible for the theft.

So far, prosecutors have pointed the finger at Oleg Yakushev, a general in the Russian police, as the man who commanded the Russian military to occupy the zone – and gave the order to plunder it.

Meanwhile, Chernobyl employees are trying to figure out the effects of the Russian occupation on radiation risks in the officially designated exclusion zone, the 30 square kilometres surrounding the Soviet power plant.

The Russian occupation begins

Employees of the Chernobyl nuclear power plant were not the only ones in the exclusion zone on 24 February. The station was guarded by 169 soldiers from Ukraine’s national guard, alongside medical staff and firefighters.

Ukraine’s State Agency for the Management of the Chernobyl Zone estimated that there were more than 300 people in the zone at the time, including four so-called “stalkers” – people who travel into the zone to explore it.

The day before the invasion, the four men had entered Pripyat, the town where employees of the ill-fated Soviet power plant lived before the 1986 disaster. They had planned to walk along a high wire stretched between two 16-storey buildings, and record the stunt from a drone. After the invasion began, they requested shelter at the power plant.

Russian troops entered the Chernobyl exclusion zone from Belarus at two points – the first near the village of Vilcha, to the north-west; the second near the village of Kamaryn, to the north-east. Armoured vehicles, including a tank, reached the main administration building at Chernobyl at around 2pm on 24 February. The Ukrainian national guard laid down their arms.

Soldiers in black uniforms with white armbands quickly broke into supervisor Geiko’s office. Together with the Ukrainian national guard commanders, he negotiated for three hours with two Russian officers, a general and a colonel. Geiko did not comment on the details of the negotiations.

The parties eventually agreed that the captured Ukrainian national guardsmen would live in two shelters in the basement of the Chernobyl administrative building, and that Russian soldiers would not be stationed directly at nuclear facilities, according to Maxim Shevchuk, deputy director of the state-owned Chernobyl management company.

The Russian officers, together with police general Oleg Yakushev, were to be housed on the fourth floor. The rest of the Russians occupied a nearby sanitary checkpoint, and demanded that the station shift supervisor seek approval for any movement of employees.

By evening, Russian forces had occupied all the strategic locations in the Chernobyl exclusion zone. Some of the Russian military remained in control of the zone, while the rest headed towards the city of Vyshhorod, closer to Kyiv, roughly 90km south of Chernobyl.

Ukrainian investigators have not been able to establish exactly how many Russian soldiers were in the Chernobyl exclusion zone, but specified that these were combined units from Russia’s Siberian military district – troops of the Russian national guard with the support of the military personnel of the Ministry of Defence.

Most of the Chernobyl power station employees, who had remained at their workplaces during the day, saw the Russian soldiers for the first time when they went to dinner that evening.

“They were dressed in black with white armbands,” recalls Vyacheslav Yakushev. This meant they were the special forces of the Russian national guard, he said.

According to him, in the dining room he also saw the soldiers from the Ukrainian national guard, now unarmed. After dinner, the employees returned to their workplaces.

Rise in radioactive dust

The Russian invasion was soon felt in the level of radiation measured in the exclusion zone. On 25 February, Chernobyl’s automated radiation sensor system went off.

Serhiy Kireev, director of the Ukrainian state company that controls the radiation sensor system, says the standard levels of radiation increased between two and eight times at certain sensors. But Kireev soon stopped receiving information about radiation levels in the zone remotely – all communications and internet connection was lost.

Why the increased radiation? As Kireev explains, when the Russian military entered the Chernobyl zone, their heavy vehicles – and the fact they drove around extensively – raised radioactive dust.

The spread of radiation is uneven in Chernobyl, so visitors and workers are meant to move around via strictly defined routes. After the 1986 accident, particles of dispersed nuclear fuel drifted in the vicinity of the plant. At the same time, the zone is also home to temporary storage sites of radioactive waste, which were used immediately after the accident. One Russian convoy crossed through an area called the ‘Western Trail’, one of the most polluted areas in Chernobyl.

The next time Kireev’s centre received data from the Chernobyl zone sensors was 2 March, just over a week after the invasion.

“The indicators had dropped,” says Kareev. This supports the idea that radioactive dust had been disturbed and then settled again, he believes.

Staff shortages, no electricity

Despite the Russian occupation, engineer Vyacheslav Yakushev continued to work.

He monitored the sensors inside the New Safe Confinement (NSC) – a sealed arch-shaped steel structure with surveillance systems that covers Chernobyl’s damaged reactor no.4. This structure was completed in July 2019 over the original shelter, which was built shortly after the accident. Vyacheslav’s workplace received data from the NSC systems. They did not change in connection with the Russian invasion.

The main problem for the power plant employees was staffing. As fighting and shelling began in the Kyiv region, an alternative route to Slavutych was cut off. On 26 February, Valentyn Geiko allowed his subordinates to rest at their workplaces. During the day, they took turns to sleep for several hours. At night, duty officers were assigned so the rest of the employees could sleep.

Despite the shutdown of internet and mobile phone networks, the station staff still had communication with the outside world. Via a landline, Geiko was in touch with the power plant’s management in Slavutych. Power plant staff also set up booths in the administration building so employees could phone their relatives. Yakushev remembers calling his colleagues, who told him to open their lockers and take their tea, sugar and cigarettes.

The Chernobyl employees tried not to cross paths with the Russian soldiers. “Internally, it was like this: you have come here, you have taken control, so you do the control, we will do our job,” Yakushev says.

That did not stop Russian forces from asking station employees to speak to the Russian Defence Ministry’s TV channel (they refused), or requesting that radiation measurements be taken together with a special Russian military team (also refused), Yakushev remembers.

Soon, the station employees had more serious problems: the electricity supply went down because of damaged power lines on 9 March. Energy company Ukrenergo said it was restoring power, but fighting was still going on near Kyiv. The station switched to a back-up voltage line from diesel generators. Yakushev recalls that there was enough fuel in the generators to last for three days.

To continue work, they had to take diesel from the Russian military, and eventually from the nearby Belarusian town of Mazyr.

New staff and crossing the river

Nearly a month had passed by the time any of the staff were allowed to go home.

The plan was this: first, 46 new shift workers would volunteer to go to the power station. In the opposite direction, 50 of the 90 employees still at the station would be allowed to leave. The remaining 40 decided to continue working.

In addition to the personnel of the Chernobyl nuclear power plant, the Russians would allow nine members of the Ukrainian national guard to leave the station – including a cancer patient – as well as one firefighter and the four “stalkers”.

The new shift understood that they were going to the Chernobyl nuclear power plant for an indefinite period. This group had two supervisors: Voloydymyr Falshovnik and Serhiy Maklyuk. Falshovnik explains that out of all the station shift supervisors, they were the only ones without small children.

Maklyuk says he was worried about the relatives he left behind in Slavutych. By this time, the town was inside Russian-controlled territory, although the Russian military had not attempted to enter it. Vyacheslav Yakushev was replaced by a neighbour from his apartment building, Serhiy Nyushev.

The new shift was transported across the Dnipro river, just a few kilometres away to the east, in a wooden boat with a motor. A middle-aged man in a hat with earflaps ferried the station personnel in groups of eight. It took him about an hour to transport one group and return.

Oleksandr Loboda, a shift supervisor who went to Chernobyl on 20 March, remembers his team feeling nervous that the Russians would not let his colleagues out.

“There was an agreement that the boat goes to the right bank with people and then brings people back, whom we replaced. This meant that the agreement was being fulfilled. And just imagine: four times the boat came back empty! We were seriously worried this was some kind of trap. Finally, the boat came back with the women. Then we exhaled,” he recalls.

On the other side of the river, the new shift was met by Belarusian border guards and Russian soldiers, then sent across the border and on to Chernobyl.

Engineer Yakushev recalls that he managed to bring his replacement up to date, then hastily changed clothes. Employees were taken out of the station, accompanied by armoured personnel carriers, and then the boatman transported them across the Dnipro. “The water was terribly cold, and we did the crossing in complete darkness,” recalls Yakushev.

“My daughter met me with a drawing saying: ‘Dad, you are our hero.’”

The Russians retreat

On 26 March – the new shift’s sixth day of working at Chernobyl – the Russian military unexpectedly entered Slavutych.

There were no Ukrainian army units in the town, only territorial defence fighters with small arms. Three of them died fighting at a checkpoint outside the town, the rest retreated, and a column of Russian vehicles drove into the main square. Slavutych mayor Yuri Fomichev was initially taken prisoner, but later released. The military tried to disperse residents, who had gathered to protest, with stun grenades and by shooting into the air.

Volodymyr Falshovnik remembers that half an hour before the fight, his wife called him and said that the Russians were going to storm the town. He tried to find out what was going on with the Russian commander at Chernobyl. According to Falshovnik, the commander “ran to call somewhere high, high in [the Russian Defence] Ministry”, but the ministry claimed there were no Russian troops there. At that point, Falshovnik told the Russian commander that Chernobyl plant staff would cease all cooperation until Slavutych was left alone.

Sure enough, the Russian servicemen left Slavutych a day later, on 27 March.

The Russians began to retreat from the Chernobyl exclusion zone altogether on 30 March, leaving the Kyiv region completely.

The next day, 14 Russian police vans drove into the station. The Russians gathered all the remaining captured Ukrainian national guard soldiers. They were taken in groups of ten to the courtyard, searched and put into the vans. Falshovnyk called the power plant management in Slavutych and informed his colleagues that “the bastards were taking away our guys”.

In response, the Russians placed Maklyuk and Falshovnyk under armed guard, and forbade them from using any means of communication.

Maklyuk remembers that as the Russians left, he could see them loading all sorts of appliances from the power station into their vehicles. Some soldiers even left spare wheels for an armoured personnel carrier behind so that they could fit more stolen goods in their vehicle, Falshovnyk says.

The Vyshhorod district prosecutor reported that the Ukrainian national guards were taken to Belarus, and later, probably, to the Russian Federation.

After the occupation

After the Russians retreated, the shift supervisors returned the Ukrainian flag – which had been removed on the second day of the occupation – to the front of the administrative building.

Then, on 3 April, the Ukrainian military entered Chernobyl. Shevchuk, the deputy director of the management company, arrived two days later. He and the staff discovered that the Russians had been digging trenches, including in the “Red Forest”, one of the places used for the temporary storage of radioactive waste, kicking up radioactive dust.

“According to the rules of radiation safety, we should not walk on the grass or kick up dust. They not only dug trenches, they also set fires and breathed the air afterwards. Now it is with them forever,” Shevchuk says.

He was more upset by the fact the Russian military had looted equipment from Ukrainian state-owned enterprises in the exclusion zone, including the radiological station, where information was received from radiological control sensors within the zone. “Now one of the main tasks is to restore everything,” Shevchuk says.

Shevchuk says the final cost of the Russian occupation to the zone’s enterprises has not yet been calculated: de-mining work is still going on in some buildings.

No one died inside the Chernobyl exclusion zone during the Russian occupation, he adds, though five Chernobyl employees – civilians in occupied regions and members of local defence forces – lost their lives elsewhere.