CHERNOBYL, Ukraine – Russian military built trenches in the earth of one of the world’s most hazardous locations Chernobyl. Ukrainian officials are concerned that they are, in effect, digging their own graves.

In the early hours of Russia’s February invasion of Ukraine, thousands of tanks and troops rumbled into the forested Chernobyl exclusion zone, stirring up highly contaminated soil from the site of the 1986 accident that was the world’s worst nuclear disaster.

For more than a month, Russian soldiers camped in the ground beside the huge structure built to isolate radiation from the crippled Chernobyl nuclear reactor. A thorough examination of their trenches was impossible because even walking on the ground is frowned upon.

As the 36th anniversary of the April 26, 1986 accident approaches and Russia’s invasion continues, it is evident that Chernobyl, a Cold War relic, was never prepared for this.

Russian military flew over the long-closed plant, ignoring the restricted airspace around it, as scientists and others looked on in bewilderment. They held staff still working at the plant at gunpoint for more than a month, with employees sleeping on tabletops and eating only twice a day.

Even now, weeks after the Russians left, the plant’s main security engineer, Valerii Semenov, told The Associated Press, “I need to calm down.” He laboured for 35 days straight, sleeping barely three hours a night, rationing smokes, and continuing on long after the Russians had left a shift change.

“I was worried they’d install something and break the system,” he explained in an interview.

Workers kept Russians away from the most dangerous sections, but the plant was without electricity, relying on diesel generators to support the essential operation of circulating water to cool the spent fuel rods, which Semenov described as the worst scenario he had experienced in his 30 years at Chernobyl.

“It was quite risky to act in this manner,” Maksym Shevchuck, deputy head of the governmental agency in charge of the exclusion zone, stated. He was terrified by it all.

According to Rebecca Harms, former president of the Greens party in the European Parliament, Russia’s invasion marks the first time when occupying a nuclear station was part of a nation’s war strategy who has visited Chernobyl several times. She called it a “nightmare” scenario in which “every nuclear plant can be used like a pre-installed nuclear bomb.”

A visit to the exclusion zone, which was more bleak than usual, revealed that the invasion posed a greater chance of disaster than the first Chernobyl explosion and fire, which sent radioactive material into the atmosphere and became a symbol of the Soviet Union’s floundering final years. The international community, including Russia, invested billions of dollars to stabilise and safeguard the region.

Authorities are now collaborating with Ukraine’s defence ministry to find strategies to defend the most vulnerable areas of Chernobyl. Anti-drone systems and anti-tank barriers, as well as a system to protect against warplanes and helicopters, are at the top of the list.

Nothing will matter if Russian President Vladimir Putin resorts to nuclear weapons, which Shevchuck says he can no longer rule out.

“I understand they can use any weapon and do anything horrible,” he stated.

According to Harms, Chernobyl requires special international protection with a strong U.N. mandate. The risks, like with the first calamity, extend not only to Ukraine but also to neighbouring Belarus and beyond.

“It depends where the wind blows,” she explained.

Harms and others were astounded by the Russian soldiers’ disdain for safety, or their ignorance, in the recent invasion after witnessing thousands of Soviet soldiers labour to limit the repercussions of the 1986 accident, often with no protection.

Some soldiers even grabbed highly radioactive stuff to keep or sell as souvenirs.

“I think kids get the impression from movies that all dangerous small things are highly important,” Shevchuck explained.

He believes that hundreds or thousands of soldiers harmed their health, most likely with little knowledge of the effects, despite warnings from factory workers to their commanders.

“The majority of the soldiers were approximately 20 years old,” he explained. “All of these activities demonstrate that their management, and human life in general, means zero in Russia.”

The exact scope of Russia’s activity in the Chernobyl exclusion zone remains unknown, particularly because the forces distributed mines that the Ukrainian military is currently looking for. Some have detonated, causing further disruption to the radioactive soils. The Russians also started many forest fires, which were quickly extinguished.

Ukrainian authorities are unable to monitor radiation levels throughout the zone because Russian soldiers confiscated the system’s main server on March 2, cutting off the link. The International Atomic Energy Agency said on Saturday that it was still not getting remote data from its monitoring equipment. The Russians even confiscated personal radiation monitors from Chernobyl workers.

The Russians robbed and left a carpet of smashed glass in the communications centre, one of the few buildings in the zone that had not been overtaken by nature. The facility had a strong 1980s vibe, with a map on the wall still depicting the Soviet Union. Someone had traced Ukraine’s border with a pink marker at some time.

In normal times, approximately 6,000 people work in the zone, roughly half of whom work at the nuclear facility and 100 are elsewhere.

The security engineer, Semenov, recalls the Russians searching the remaining staff for “radicals.”

“We said, ‘Look at our documents, 90% of us are from Russia,'” he explained. “But we’re patriots for our nation,” he says, referring to Ukraine.

When the Russians rushed out of the region on March 31, leaving behind charred tanks and frightened towns, they took more than 150 Ukrainian national guard troops with them. Shevchuck believes they’ve arrived in Russia.

In their haste, the Russians offered nuclear plant managers a choice: sign a certificate stating that the military had defended the station and that there had been no complaints, or be deported to Belarus. The executives agreed to sign.

The Russians did appear to take one protective measure, which was to leave open a wire that routed communications from the nuclear facility through the workers’ hamlet of Slavutych and on to officials in Ukraine’s capital, Kyiv. Shevchuck stated that it was utilised multiple times.

“I think they realised it had to be for their own protection,” he said. According to the IAEA, the plant can now immediately contact Ukraine’s nuclear authority.

Another Ukrainian nuclear power station, in Zaporizhzhia, southeastern Ukraine, is still under Russian control. It is Europe’s largest.

Shevchuck, like many other Ukrainians, has had enough of Putin.

“We’re encouraging him to come inside the new safe confinement facility,” he explained. “Then we’ll shut it down.”