A crew of workers were trapped at nuclear site under Russian occupation — until brave compatriots gathered to take their place.

This piece is adapted from “Chernobyl Roulette: War in the Nuclear Disaster Zone,” Serhii Plokhy’s forthcoming book documenting the 2022 invasion and occupation of the Chernobyl and Zaporizhzhia nuclear sites in Ukraine. Plokhy, a professor of Ukrainian history at Harvard University, is also the author of “Chernobyl: The History of a Nuclear Catastrophe.”

On Feb. 24, 2022, the first day of Russia’s full-scale invasion of Ukraine, armored vehicles approached the Chernobyl nuclear power station. Russian occupation of the plant, which would last 35 days, had begun.

The invasion trapped the crew of workers on duty at the facility, famous for the nuclear disaster there in April 1986. While no longer a working power station, the site requires constant upkeep of systems that contain radioactive waste. For more than three weeks, workers who had arrived for a scheduled 12-hour shift remained on the job as prisoners behind enemy lines, until finally the Russians agreed to allow a second shift to replace them.

The danger is not over. The International Atomic Energy Agency warned this month that security conditions at the Zaporizhzhia nuclear plant, which Russian troops still control, continue to deteriorate.

This account, told largely in the workers’ own words, focuses on the effort to replace that exhausted first shift with heroic Ukrainian volunteers, in a tense exchange carried out at Russian gunpoint through a war-torn land.

‘We were already walking around like ghosts’

The pressure was taking its toll.

Valentyn Heiko, the 59-year-old foreman of a Chernobyl night shift that had stretched to three weeks and counting, had convinced the Russian occupiers to give every staff member a daily medical check in which their blood pressure was measured and their psychological condition evaluated. “And we saw the statistics, which showed that their emotional and physical condition was deteriorating with every passing day,” recalled Valerii Semenov, a senior engineer in charge of the physical security of the facility.

Oleksandr Kalishuk, an engineer with the plant’s physical safety service, recalled the case of a young colleague, about 25, who lost control and shouted obscenities at the Russian guards. They were under orders not to react, but Kalishuk heard one of them say, “Why think? Pull the trigger and fire.” Kalishuk tried to talk sense to the young man: “Just imagine the reaction of an armed man. You’re insulting him. He can use force. And heroism consists precisely in controlling yourself.” The Ukrainian worker was responsive but told Kalishuk: “I hate them.”

“We worked almost around-the-clock. We rested a few hours according to schedule. We became exhausted,” said safety engineer Liudmyla Kozak. “We asked to be relieved because we were already walking around like ghosts.”

Oleksii Shelestii, chief electrical engineer on the shift, said he was close to a nervous breakdown by the end of the second week. “What’s up?” Shelestii asked his superiors in a phone call to the plant’s headquarters in Slavutych, about 45 kilometers to the east. “Can’t you come to an agreement here? … We need to be relieved; we’re tired. We weren’t prepared for this, morally or physically.” He suspected the managers were doing all they could, but that the authorities in Kyiv were unresponsive.

The Russian commanders at the station realized they were sitting on an explosive nuclear barrel. The exhaustion and resentment of the Chernobyl personnel might well lead to an accident that would claim the lives of the occupiers. The Russians were prepared to allow a shift change, but how were they to evacuate those on duty and bring in replacements?

“How did you get here before?” one of the Russian commanders asked Heiko. “Take a look,” Heiko responded, “and count on your fingers: The highway bridge has been destroyed, and nobody will take the route through Belarus because more people like you are stationed there; no one will send people that way. The railway bridge that people used to take has also been destroyed. … So other routes of some kind have to be found.” The Russian responded: “Fine — make your proposals.”

Heiko and the plant managers in Slavutych ultimately decided that new personnel could be brought in only by the Belarusian route, crossing the Dnieper River by boat. The alternative route, through Kyiv, was more dangerous. So Belarus it was.

The Russians gave their approval. They would take the old shift as far as the Dnieper and pick up the new one, but plant management would have to take care of the travel arrangements to and from Slavutych.

“At that moment, the director was faced with the following conditions: Decide on your own, search on your own, act on your own,” Heiko recalled.

‘Hardest of all was convincing my wife I had to go there’

Valerii Seida, the plant’s director, had to select the members of the new shift —­ people ready to risk their freedom, and perhaps their lives, by going into Russian captivity. The trip might become a one-way ticket.

Surprisingly, there was no lack of volunteers.

On the first day of the war, when Ihor Aleksandrov, chief foreman of the plant, asked a roomful of operators for volunteers, everyone responded positively. Many knew exactly whom they would replace. Serhii Niushev, for example, was ready to replace his next-door neighbor Viacheslav Yakushev. A woman from Slavutych volunteered to join the kitchen staff at the plant, as her husband and son were there — members of a Ukrainian National Guard unit that had been captured and held at the plant by the Russians. She wanted to be with them. After a tense standoff on the first day of the war, the Guardsmen, who were armed only with light weapons, decided to lay them down to avoid a battle with Russian tanks and heavy artillery on the plant grounds. Neither they nor the firefighters present at the site were included in the “exchange.”

Volodymyr Falshovnyk and Serhii Makliuk were selected to lead the new shift. This made sense: Heiko’s experience had shown that, with shifts lasting days and weeks rather than hours, there was more than enough work for two foremen. Falshovnyk and Makliuk were among the most experienced people at the station, but the key factors determining their selection were their family situations. Falshovnyk, a calm, soft-spoken family man, recalled that “in my case, thank God, my children provide for themselves, and that might be the reason I was chosen: because the children of all the other shift foremen at the plant are of school age.”

Such considerations indicated how risky the mission was. “Hardest of all was convincing my wife I had to go there,” Falshovnyk said. For Makliuk, the most difficult decision was to leave his family behind in a city — Slavutych was behind Russian lines but still free — that might fall into enemy hands any day.

While everyone agreed that the shift at the Chernobyl plant had to be replaced, and volunteers were prepared to step in, there was no agreement with the Russian occupying force on how and when that could be achieved. “It was clear that in the next days and weeks, we could only prepare,” said Falshovnyk. “Nothing would happen earlier, especially with active fighting going on there, as well as near the station and closer to Kyiv.”

The members of the replacement shift, a total of 46 men and women, could only wait.

‘They told us: ‘Be quick, girls. We’re leaving’ ’

According to staff member Zoia Yerashova, plant employees knew there were volunteers in Slavutych ready to replace them: “Everyone said that there were people in the city prepared to go, that there were such heroes — heroes, indeed — who knew where they were going. That our people were no longer [in charge] there. That there were foreigners who had seized the station, but there was a substitute for every worker. And that everyone was prepared to go there for the rotation.”

But there was no telling whether a shift from Slavutych would safely reach the plant or what would happen to Heiko’s shift: Would they be allowed to go home or arrested on departure? Nadia Sira, another member of Heiko’s shift, decided to leave, but only with a group led by Heiko. “I said right away that I would go only if the shift foreman and all the men went,” she said. “If they brought only the women, who knew where they would take us?”

Preparations for the rotation began in mid-March, with Heiko calling Shelestii and asking him to prepare lists of his staff to be rotated. No one trusted the Russians, and there was concern that they might bring in the new shift while keeping the old shift at the station or moving them somewhere else, still holding everyone hostage. Another problem was how to keep the station working during the shift change itself. It was decided that the staff would rotate in two stages: The women and nonessential personnel would go first, and operators essential for the functioning of the station’s equipment would leave after the first group of the new shift arrived.

Everything was ready, but the dates kept changing, as the plan required high-level coordination in both Russia and Ukraine. There was one false alarm after another. Groups gathered and then dispersed.

On March 20, more than three weeks into the shift, Heiko ordered his staff to be ready for departure by 8 a.m. “They told us: ‘Be quick, girls. We’re leaving — they’re waiting for us,’” said Yerashova. At the entrance to the administration building, they were checked by Russian soldiers before getting on the buses. “The buses drove up; they had tied white flags onto them,” she recalled. “We boarded one by one, and they seated us. The Russian general Aleksei Rtishchev then made his appearance. He called out the names of those already on the bus and gave them permission to leave.”

Engineer Oleksandr Kalishuk, who was on the bus, said that as they were all anxiously waiting to depart, they heard Heiko’s voice on the public address system: The departure had been postponed again. Heiko asked everyone to return to their workplaces, but the passengers who had waited so long to go home refused to get off. Gen. Rtishchev went into the building to see what was going on and came back with even more disturbing news: The Ukrainians supposedly regarded the employees of the Chernobyl plant as collaborators and were refusing to accept them. It was a lie, but it didn’t matter: The buses were not moving.

Thoroughly disappointed, the employees left the bus and returned to their overcrowded quarters. But Heiko’s voice was soon heard again: The rotation would go ahead. He was working on the logistics and would keep everyone posted.

The long-awaited announcement finally came at 10 a.m. Heiko ordered the staff back onto the buses.

Fifty employees left the plant, including 16 women, eight members of the Ukrainian National Guard contingent and one member of the fire brigade; the remainder were from the operational and kitchen staff. The Russians also released four male civilians who had been picked up in the Chernobyl Exclusion Zone and another National Guardsman with cancer. The rest of the group were male engineers and technicians.

The buses, escorted by Russian armored personnel carriers, proceeded toward the town of Chernobyl, reaching the Leliv checkpoint on the border of the inner 10-kilometer exclusion zone, part of the buffer established after the 1986 nuclear disaster. Then they crossed the Pripyat River and left the 30-kilometer exclusion zone at the Paryshiv checkpoint. From there, the column headed for the Belarusian border, crossing it near the village of Hdzen on the Brahinka River.

“We proceeded under escort of the armored personnel carriers,” recalled Liudmyla Mykhailenko, a nurse. Along the road, she saw dozens of Russian military vehicles. “It was frightening, so there was silence and fear,” she said.

“We were very afraid,” echoed Yerashova, “because we had already heard that ‘green corridors’ had been granted at some places in Ukraine; that [the Russians] did not observe them; that some [evacuees] had been executed. We dismissed such thoughts, convincing ourselves all would be well.”

“I kept reassuring myself that we were going home,” Sira said with tears in her eyes. She was traveling with her son, also a shift worker, and was concerned for him more than for herself. “I wept very softly,” she recalled. “My son said, ‘Mama, they’ll bring us home.’ But I said, ‘They’re probably taking us as hostages, or to Belarus or Russia.’”

At the Belarusian border, everyone was ordered to disembark and go through the checkpoint one by one. The guards examined their documents and personal belongings.

Sira could not hide her emotions. She was married to a Belarusian, and they had visited his family not long before the invasion. “Don’t cry, everything will be all right,” said a female border officer, trying to calm her. But Sira was inconsolable. “What do you mean, ‘It will be all right?’ We were in your country a month ago, and everything was all right. … We will never see [my husband’s family] again. That’s it.” Sira knew that the war had changed relations between the two peoples for years if not generations to come.

The Ukrainians got back on the buses and the column moved farther east, toward Slavutych. They crossed the approximately 20-kilometer “peninsula” of Belarusian territory protruding into Ukraine between the Brahinka and Dnieper rivers. The bridge across the Dnieper connecting Belarus with Ukraine had been blown up, and the border checkpoint in the village of Komaryn was no longer in use. There were still guards on the Belarusian side of the border, but none on the Ukrainian side.

Awaiting the Ukrainian passengers was a welcoming party led by Director Seida and the members of the new shift, headed by Falshovnyk and Makliuk.

‘Such exhaustion that it will always be before my eyes …’

Seida was tasked with getting the two shifts across the river. Yevhen Kosakovsky, a volunteer from Falshovnyk’s shift, recalled that there was a big, comfortable-looking motorboat next to the crossing, but the Russians insisted on a small wooden boat with an open deck so they could see everything and everyone. Kosakovsky said it was not easy to find a fisherman willing to ferry them across. “The negotiations were difficult and broke off several times,” he said. “Some of the fishermen did not want to risk their lives and their boats, while others said taking our personnel across to an occupied station would make them collaborators.”

Eventually, Seida and his people turned to Natalia Muzyka, mayor of the small fishing village of Mnev on the Ukrainian side of the river. Muzyka agreed to help. In 10 minutes, two local fishermen got into a small wooden boat they had built themselves and headed 12 kilometers downriver to the place where the new shift workers were waiting. The Russians ordered the fishermen to put a white flag on the boat. They did not want them to take anyone to the Ukrainian side of the river until all the members of the new shift had been transported to the Belarusian side.

“It was agreed that the boat would take people to the eastern bank and come back with people whom we were replacing. That would mean the agreement was being fulfilled,” said Oleksandr Loboda, a member of the new shift. But the boat that took their colleagues to the Belarusian side returned to the Ukrainian side empty. “And just imagine: The boat returned empty four times,” Loboda said. “We were seriously apprehensive, thinking it was a trap of some kind. But then, finally, the boat returned with the women. Then we breathed a sigh of relief.”

Russians armed with machine guns escorted people in groups of eight down the hill to the riverbank. Zoia Yerashova recalled that there was a soldier at the front of each group and another at the back. Upon reaching the bank, they would get into the wooden boat one by one. It was unsafe for more than a few people at a time, but it was open like the Russians wanted. “There were people who had never seen a boat in their lives,” recalled Chobotar, one of the fishermen who ferried the plant workers across.

A single crossing took between 15 and 20 minutes. Altogether, the fishermen made two dozen trips across the river. The members of the two shifts met one another on the Belarusian side of the river. “There came the highly emotional moment of meeting our replacements,” said Liudmyla Mykhailenko, the nurse from Heiko’s shift. “We had literally seconds, or at most a minute, to embrace and shed tears. We had spent 25 days in [limited] company, and here were our people from Slavutych.”

The members of the new shift were taken aback to see how their friends had changed. “I crossed paths with the bus that brought the personnel from the station,” said Kosakovsky. Seeing his colleagues, he was shocked by “the gaze of people who perhaps were not afraid —­ it was probably exhaustion, but a gaze of such exhaustion that it will always be before my eyes. It was, of course, so terrible.”

Heiko, the foreman, left the station with the second group late in the afternoon of March 20. To those who came to replace him, he seemed unaffected by the stress of the previous weeks. “It was pleasant to see Valentyn Heiko safe, sound and active,” recalled Falshovnyk. The other new foreman, Makliuk, had the same impression. “I thought he would be all exhausted and depressed, but no: He was in fine form. So energetic, ready to work — he told us everything.” After bringing Falshovnyk and Makliuk up to speed, Heiko left the station and headed toward the river crossing. He still had a duty to carry out as foreman: to report to the station director.

When the last members of Heiko’s shift crossed the river, it was already dark. Seida welcomed his people on their return to the Ukrainian side of the border. He offered them tea, coffee and cigarettes. “We will do all we can for you,” he told the returnees. Viacheslav Yakushev recalled that everyone thanked him. Then, as they boarded buses bound for Slavutych, Heiko, who had been one of the last to cross the river, approached Seida. “I have a present for you,” he told the director. Reaching into his small bag, he produced a blue and yellow Ukrainian flag, which he had persuaded the commander of the invading Russian forces to entrust to him after the station’s takeover. Seida accepted the gift.

It was Heiko’s last action as foreman of a shift that had lasted 25 days and nights. Keeping the flag safe had been the ultimate act of defiance.

‘We’ll make such a dirty nuclear bomb that you will never get out of here’

Once the 46 men and women on the new shift had made it to the Russian-controlled Belarusian side of the river, they were loaded aboard the buses. The column — consisting of two armored personnel carriers in the lead, three buses with the new arrivals in the middle, and a microbus full of Russian soldiers and another armored personnel carrier at the back — set off toward the station.

In Heiko’s view, the volunteers were heroes. “They were going into the unknown,” he said later. “No one knew how it would end or how long they would be there. We had come out all right. I always said that the stars had been in such a constellation that we were on duty that day and had nowhere else to go, but those on their way there — it was all much more complicated for them.”

Heiko and his crew had spent 600 hours on duty at the occupied nuclear power plant. It was anyone’s guess how long Falshovnyk, Makliuk and the rest on the new shift would be there.

Falshovnyk and Makliuk reached the station around 3 p.m. on March 20. At 4:30, having received instructions and updates from Heiko, Falshovnyk took over control of plant operations. Soon after, the Russians paid the new foremen a visit. “Their leaders came — the colonels and generals — and said right away: ‘Guys, nothing here is your Ukrainian property. We’ll take what we need. At best, we’ll let you know. But your response will be of no interest to us,’” Falshovnyk recalled. He had already heard from Heiko that the Russians set the rules and expected obedience. Still, he was shocked by their dismissive attitudes.

“The first days were actually occupied with getting used to being at war, although there was no shooting there,” said Falshovnyk. Heiko had left him a memo describing the structure of the Russian forces at the station, which Falshovnyk greatly appreciated. “There were quite a few military organizations of all kinds on-site,” he said. “National Guard, special forces, ‘normal’ armed forces, so to speak, and representatives of Rosatom,” Russia’s state-run nuclear energy company. He spent long hours trying to understand which officials he was dealing with.

It helped that not everyone on Heiko’s shift had left the plant. Sixteen engineers and mechanics had stayed behind for various reasons. For one, those who lived somewhere other than Slavutych — such as Kyiv or Chernihiv — could not easily go home, as the war raged on around those cities. The residents of Ivankiv, a settlement north of Kyiv, could not go back because their town was under Russian occupation. Others decided to stay so as not to expose themselves and those who would replace them to the risk of being detained by the Russians en route. Still others, knowing the food supply was dwindling in Slavutych, decided not to make the situation more difficult for their families by returning.

There was one more reason to stay at the plant: The new shift needed help. Forty-six people simply could not manage work that was normally assigned to 100.

The Russians were under orders not to touch the Ukrainian personnel, but discipline was hardly their strong suit. Makliuk recalled that at the station itself, the Russian soldiers did not threaten or intimidate the workers. But outside the premises, things could get rough. “When staff members drove or walked beyond the bounds of their immediate workplaces, there were incidents,” he said. “They aimed grenade launchers at people. Such things happened. And when a vehicle was taking garbage to Leliv, they aimed machine guns at the driver on his way there and back. And there were similar incidents on the production site.”

The greatest problem with the Russian occupiers was the constant looting of anything and everything they could get their hands on. “Before we arrived, half the [administration] building was already smashed up — doors broken — and looted,” said Falshovnyk.

Russian looting of valuable equipment at the station made international headlines a few days after Falshovnyk and his shift arrived. On March 23, CNN reported that the Russian occupiers had destroyed the E.U.-funded radiation monitoring lab and removed radioactive samples. To deal with the international scandal, the Russian military’s official television channel sent reporters to the site.

The footage aired left no doubt that the laboratory had indeed been ransacked. The camera showed computers with their hard drives ripped out and pieces of equipment scattered around the room, as well as toilet paper and an abundance of empty liquor bottles. The reporters claimed that the Ukrainians themselves were responsible. According to Russian television, the disrepair had been arranged to “create a negative impression of the Russian military, of its activity in Ukrainian territory, and specifically in the territory of Chernobyl and the Chernobyl station.”

The Russian commanders tried to stay on relatively good terms with the new shift, both because their own radiological safety depended on the Ukrainian staff’s compliance and because they needed assistance with such mundane matters as garbage disposal. But relations between the occupiers and the staff deteriorated dramatically on March 24, the fifth day of the new shift.

On that day, Falshovnyk received a disturbing call from his wife in Slavutych: Russian troops had launched an attack on the city. Management at station headquarters in Slavutych had confirmed the news.

Slavutych, still behind enemy lines, was about to become a battleground between the Russians and the city’s defense unit. Distressed, Falshovnyk confronted the military commanders: They had promised Russian forces would not touch Slavutych, if for no other reason than self-interest, according to Falshovnyk. After all, they were well aware that “the next personnel rotation was necessary: If active measures were to begin here, the personnel would simply scatter, and there would be no one to take our places.”

The Russians themselves appeared surprised. They assured Falshovnyk that they had nothing to do with what was happening in the city. They called their superiors, all the way up to the Ministry of Defense. But the answer they passed on to Falshovnyk was as disappointing as it was cynical: “There are no regular troops of the Russian Federation at Slavutych.”

Falshovnyk and the others were incensed. As far as they were concerned, their informal arrangement with the Russians was off. “We declared that we were terminating any cooperation with the occupiers until order was restored in Slavutych and until it was left in peace,” said Falshovnyk.

Vitalii Popov, a member of the new shift, recalls reacting to the news: “We all went nuts.” Falshovnyk and Makliuk threatened the Russians by saying the shift would stop working if the attacks continued. “That would simply threaten an ecological catastrophe. ‘Look, you will be responsible for the consequences because, as a matter of fact, the personnel are working under the barrel of your gun.’” Popov and his colleagues pushed an even more radical line. “We didn’t just sit idly by. We threatened the armed forces of the [Russian Federation] in every possible way, beginning with direct contacts: ‘You will perish here, because we’ll make such a dirty nuclear bomb that you will never get out of here.’”

One week later, the Russians would be gone.