CHERNOBYL, Ukraine – As the launch site for an attack on the Ukrainian capital Kiev, the Chernobyl exclusion zone, one of the most toxic places on Earth, probably wasn’t the best choice. But that didn’t seem to bother the Russian generals who took over the site in the early stages of the war.
“We told them not to, it was dangerous, but they ignored us,” Valeriy Simyonov, chief safety engineer for the Chernobyl nuclear site, said in an interview.
Apparently undeterred by security concerns, Russian forces stomped across the site with bulldozers and tanks, dug trenches and bunkers — and exposed themselves to potentially harmful doses of radiation that lingered below the surface.
During a visit to the recently liberated nuclear power plant, site of the world’s worst nuclear disaster in 1986, winds blew clouds of dust along the roads, and scenes of disregard for safety were everywhere, although Ukrainian nuclear officials say no major radiation leak was caused by Russian military occupation of a month.
At just one site with extensive trenches, a few hundred yards outside the city of Chernobyl, the Russian military had dug an extensive maze of sunken walkways and bunkers. An abandoned armored car was nearby.
The soldiers had apparently camped in the radioactive forest for weeks. Although international nuclear safety experts say they have not confirmed any cases of radiation sickness among the soldiers, the cancers and other potential health problems associated with radiation exposure may not develop until decades later.
Mr Simyonov said that the Russian army had deployed officers from a nuclear, biological and chemical unit, as well as experts from Rosatom, the Russian state nuclear power company, who had been consulting with Ukrainian scientists.
But the Russian nuclear experts seemed to have little influence over the army commanders, he said. The military seemed more preoccupied with planning the attack on Kiev and, subsequently failing, using Chernobyl as an escape route to Belarus for their badly mauled troops.
“They came and did what they wanted” in the zone around the station, said Mr. Simyonov. Despite the best efforts of him and other Ukrainian nuclear engineers and technicians who remained at the site during the occupation, working around the clock and unable to leave except for one shift change in late March, the bulwark continued.
The earthworks were not the only case of recklessness in handling a site so toxic that it still has the potential to spread radiation far beyond Ukraine’s borders.
In a particularly ill-advised move, a Russian soldier from a chemical, biological and nuclear protection unit picked up a source of cobalt-60 with his bare hands at a waste dump, exposing himself in seconds to so much radiation that it fell off the scales of a Geiger counter, said Mr. Simyonov. It is not clear what happened to the man, he says.
The most troubling moment, Mr Simyonov said, came in mid-March, when electrical power was cut off for a cooling pool that stores spent fuel rods containing many times more radioactive material than was dispersed during the 1986 disaster. That raised concerns among Ukrainians about a fire if the water cooling the fuel rods boiled away, exposing them to air, though that prospect was quickly dismissed by experts. “They highlight the worst-case scenarios, which may but not necessarily be plausible,” said Edwin Lyman, a reactor expert with the Union of Concerned Scientists.
The greater risk with a prolonged power outage, experts say, was that hydrogen generated by the spent nuclear fuel could build up and explode. Bruno Chareyron, lab director at CRIIRAD, a French group that monitors radiation risks, cited a 2008 study of the Chernobyl site as suggesting it could happen in about 15 days.
The march to Kiev on the west bank of the Dnipro River began and ended in Chernobyl for the 31st and 36th Combined Armies of the Russian Army, traveling with an auxiliary unit of special forces and ethnic Chechen fighters.
The formation invaded Ukraine on February 24, fought in the outskirts of Kiev for most of a month, then withdrew, leaving behind burnt armored vehicles, their own casualties of war, widespread destruction and evidence of human rights abuses, including hundreds of civilian bodies on the streets in the city of Bucha.
As they withdrew from Chernobyl, Russian troops blew up a bridge in the exclusion zone and laid a dense maze of anti-personnel mines, trip cables and booby traps around the defunct station. According to the Ukrainian government agency that manages the site, two Ukrainian soldiers stepped on mines in the past week.
As a bizarre final sign of the unit’s misadventures, Ukrainian soldiers found discarded devices and electronic goods on roads in the Chernobyl zone. These were apparently looted from towns deeper in Ukraine and driven out for reasons unknown in the final retreat. Reporters found a washing machine on a roadside just outside the city of Chernobyl.
Employees of the Chernobyl-based exclusion zone management agency have suffered under the Russian occupation, but nothing comes close to the barbarity wrought by Russian forces in Bucha and other towns around Kiev.
The Russians had come in seemingly endless columns on the first day of the war, said Natasha Siloshenko, 45, a cook at a cafeteria serving nuclear workers. She had watched carefully from a side street.
“There was a sea of vehicles,” she said. “They came in waves through the zone and drove quickly towards Kiev.”
There was little or no fighting in the zone, as far as she could tell. The armored columns just passed through.
During the occupation, Russian soldiers searched the apartments of nuclear technicians and engineers, firefighters and support personnel in the city of Chernobyl. “They took valuables” from apartments, she said, but there was little violence.
Workers tried to warn the Russians about radiation risks, but to no avail.
The background radiation in most of the 18-mile exclusion zone around the nuclear power plant poses little risk after 36 years and is roughly equivalent to a high-altitude airplane flight. But in invisible hot spots, some covering an acre or two acres, others just a few square meters, radiation can reach thousands of times the normal ambient level.
A soldier in such a place would be exposed every hour for a whole year to what experts consider a safe limit, said Mr Chareyron, the nuclear expert. The most dangerous isotopes in the soil are Cesium 137, Strontium 90 and various isotopes of plutonium. Days or weeks spent in these areas carry a high risk of causing cancer, he said.
Throughout the zone, radioactive particles have entered the ground to a depth of several centimeters to a foot. They pose little danger if left underground, where their half-lives would last mostly harmless for decades or hundreds of years.
War between Russia and Ukraine: important developments
Missile attack. A rocket attack on a crowded train station in eastern Ukraine left at least 50 dead and nearly 100 injured, Ukrainian officials said, blaming Russia for hitting a key evacuation point for those trying to flee ahead of an expected, stepped-up offensive.
Until the Russian invasion, the main threat from this contamination was its ingestion into mosses and trees that can burn in forest fires, the dispersion of the toxins in smoke, or by birds that eat radioactive ground-dwelling insects.
“We said to them, ‘This is the zone, you can’t go to certain places,'” Ms Siloshenko said the workers had told the Russians. “They ignored us.”
In a dug-in position, Russian troops had dug a bunker on the sandy side of a roadside, leaving behind mounds of rubbish — food wrappers, discarded boots, a blackened cooking pot — suggesting they had lived in the underground space for a long time.
Nearby, a bulldozer had cleared the topsoil to build berms for artillery emplacements and half a dozen foxholes.
The forest surrounding it had recently burned down, indicating that a fire had raged over the area during the Russian occupation, adding radioactive smoke to the Russian soldiers’ exposure, along with dust from disturbed ground.
The director-general of the International Atomic Energy Agency, Rafael Mariano Grossi, issued a statement on Thursday saying that the agency was unable to confirm reports of Russian soldiers becoming ill from radiation in the zone or provide an independent assessment of the radiation levels at the site. The Chernobyl agency’s automated radiation sensors have been out of order for more than a month, he said.
The Ukrainian government’s radiation monitors stopped working on the first day of the war, said Kateryna Pavlova, a spokeswoman for Ukraine’s Chernobyl Zone Management Agency. Measurements from satellites, she said, showed slightly increased radiation in some areas after the Russian occupation.
Armored vehicles that run on treads rather than wheels pose the greatest risk to radiation safety in a wider area as they shake up and spread the radioactive soil to areas in Belarus and Russia as they retreat, Ms Pavlova said. “The next person that comes along could be infected,” she said.
Although the five-day power outage did not lead to disasters, it was still a cause for huge concern among plant operators, said Sergei Makluk, a shift chief interviewed at the nuclear plant on Thursday evening.
The backup generators that came into operation require about 18,000 gallons of diesel fuel per day. In the early days, Russian officers assured factory workers that they would have enough fuel from supplies brought in for armored vehicles during the fighting in the outskirts of Kiev, Mr. Makluk. But on the fifth day, with the military’s well-documented logistical problems, the officers said they would no longer supply the diesel.
“They said, ‘There is not enough fuel for the front,'” and that a power cable to Belarus should be used to draw electricity from the Belarus grid to instead cool the waste basin.
Mr Simyonov, chief safety engineer, described the threat to stop diesel supplies for generators as “blackmail” to force the authorities in Belarus to solve the problem. Whatever the case, the electricity was restored in time and the nuclear fuel never came close to overheating.
All in all, trench digging and other dubious activities posed a much smaller risk than the waste pool, and most of it to the Russian soldiers themselves, Mr. Simyonov said, wryly adding: “We invite them to dig more trenches here, if they want to.”
Reporting contributed by William J. Broad From New York.