In 1986, when Ukraine was still part of the Soviet Union, it was the site of the world's

worst nuclear disaster.

Chernobyl is a word that everybody around the world knows because of its terrifying

history.

That's our colleague, Joe Parkinson.

The Chernobyl plant, it's a complex of many buildings, smoke stack chimneys and the

kind of centerpiece, if you like, of the site is reactor number four, which exploded.

The danger may be escalating.

It's an atomic fire and the Soviets can't contain it.

To contain the disaster, a giant structure of steel and concrete was built to surround

the exploded reactor.

In the area around Chernobyl, became an abandoned wasteland.

Nothing new has been built there.

The power plant is completely shut down.

But since that accident more than three decades ago, thousands of people have continued to

work at the plant.

Their job is to keep all the nuclear waste safe underground.

There are scientists monitoring radiation levels and tracking the conditions inside the

sarcophagus and engineers doing maintenance.

On the very first day of the Russian invasion of Ukraine, Russian troops took over Chernobyl

and took some 200 Ukrainians who were on shift there hostage.

Those workers have now been held inside the power plant for three weeks, working around

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