Ukrainians shocked by ‘crazy’ scene at Chernobyl after Russian pullout reveals radioactive contamination

(CNN) -- The sudden ear-piercing beep of a radiation meter fills the room as a Ukrainian soldier walks in.

This is where Russian soldiers were living at the Chernobyl nuclear power plant, and radiation levels are now higher than normal.

There's no visible presence of the source of the radioactive material in the room, but Ukrainian officials say it's coming from small particles and dust that the soldiers brought into the building.

"They went to the Red Forest and brought radioactive material back with them on their shoes," soldier Ihor Ugolkov explains. "Other places are fine, but radiation increased here, because they were living here."

CNN was given exclusive access to the power plant for the first time since it came back into Ukrainian control.

Officials at the plant explain the levels inside the room used by Russian soldiers are only slightly above what the World Nuclear Association describes as naturally occurring radiation.

One-time contact would not be dangerous but continuous exposure would pose a health hazard.

"They went everywhere, and they also took some radioactive dust on them [when they left]," Ugolkov adds.

It's an example of what Ukrainian officials say was the lax and careless behavior of Russian soldiers while they were in control of the site of the 1986 nuclear disaster.

The area around Chernobyl, namely the Red Forest, is still the most nuclear contaminated area on the planet, with most of the radioactive particles present on the soil.

Ukrainian officials have released drone footage of what they say were trenches dug by Russian soldiers in that area, which is particularly radioactive.

At a safe location, on the edges of that area, CNN saw a Russian military ration box that exhibited radiation levels 50 times above naturally occurring values