It was Tuesday the 36th anniversary of the tragedy, and the European Union warned of a possible new nuclear disaster in Ukraine because of the war.

After weeks of occupation by the Russian army, the sprawling site hosting the double sarcophagus that covers the destroyed reactor of the nuclear power plant has returned to Ukrainian control.

On the road from kyiv to Chernobyl, near the Belarusian border, soldiers armed with assault rifles guard checkpoints, one of which sports a mannequin in Russian fatigues and gas mask.

But concern remains high over nuclear sites in Ukraine as the Russian invasion, launched on February 24, continues.

Ukrainian authorities said on Tuesday that missiles had grazed, at low altitude, the Zaporozhye nuclear power plant in the south of the country.

The Chernobyl staff "continued their work, despite all the difficulties (...) They stabilized the situation, so to speak, in the sense that the worst was avoided", Rafael Grossi told the press. , the head of the International Atomic Energy Agency (IAEA), arriving at the site.

"We don't have peace yet, so we have to continue. The situation is not stable. We have to stay alert," he added, speaking of a "very, very dangerous" invasion.

The plant, taken by the Russian army on the first day of the offensive, was deprived of power and communications, raising fears of a new disaster on the site.

Ukrainian soldiers next to a statue paying tribute to the firefighters who died in the 1986 disaster, April 26, 2022 Sergei SUPINSKY AFP

On April 26, 1986, reactor number 4 of the Chernobyl power plant, then located in the USSR, exploded.

The nuclear accident, considered the worst in history - worse than that of Fukushima, Japan, in 2011 - left at least hundreds dead and much of Western Europe suffered radioactive fallout.

"Chernobyl Ice Cream"

A double sarcophagus now covers the reactor building number 4 to limit radioactivity on the site and an "exclusion zone" within a radius of 30 km around the plant remains almost uninhabited, explain the nuclear authorities.

The road leading to the site is lined with derelict apartment buildings.

But curtains hang from the windows of some apartments, plants are maintained and a kiosk with the sign "Chernobyl Tour Info" welcomes people who go to the plant.

A shack painted nuclear yellow bears the scars of the Russian invasion launched on February 24, with its windows shattered by bullet holes.

On the kiosk's refrigerator, a sign from when tourists were welcome offers "Chernobyl Ice Cream," with a design where a cone of vanilla ice cream sits alongside the radiation alert symbol.

Russian troops that could have easily passed the stand on their way south towards kyiv had planned to stay in Chernobyl, according to Ukrainian officials.

Soldiers dug trenches and set up camps in areas like the "Red Forest", so named because of the color its trees took on after being hit by a heavy dose of radiation when Reactor 4 exploded in Chernobyl.

"Areas with high levels of radiation remain here, but contamination has shifted due to the actions of Russian occupiers using heavy military vehicles," Ukrainian Interior Minister Denys Monastyrsky told reporters visiting the site. .

IAEA Director General Rafael Grossi visiting the Chernobyl site in Ukraine, April 26, 2022 Sergei SUPINSKY AFP

The original Soviet-era sarcophagus deteriorated over the years, so a new sarcophagus was built over it, completed in 2019.

But for some locals, risk is part of life.

"If they (the Russians) wanted to blow it up, they could blow it up by running away," noted Valeriy Slutsky, 75, who says he witnessed the plant disaster in 1986. "Maybe I'm used to (radiation)," he added with a shrug.

© 2022 AFP