Giant arch slides over Chernobyl site to block radiation for a century

A worker is seen in front of a New Safe Confinement (NSC) structure over the old sarcophagus covering the damaged fourth reactor at the Chernobyl nuclear power plant, Ukraine, November 29, 2016. REUTERS/Gleb Garanich

CHERNOBYL, Ukraine (Reuters) - In the middle of a vast exclusion zone in northern Ukraine, the world's largest land-based moving structure has been slid over the Chernobyl nuclear disaster site to prevent deadly radiation spewing from the stricken reactor for the next 100 years.

On April 26, 1986, a botched test at the Soviet nuclear plant sent clouds of smouldering nuclear material across large swathes of Europe, forced over 50,000 people to evacuate and poisoned unknown numbers of workers involved in its clean-up.