The disaster forced the evacuation of a 30-kilometer zone around the site. More than 100,000 people were evacuated from their homes.
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A worker measures radiation levels at the power plant.
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People are scanned for radioactivity before evacuating.
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Customs officials in Germany closely screen goods, cars and people coming in from Eastern Europe in May 1986. Radioactivity from the Chernobyl nuclear plant threatened to contaminate crops.
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In Finland, milk is tested by authorities for effects of the radiation.
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A farmer in Sweden wears a protective suit as he sifts hay possibly contaminated by the radioactive cloud from Chernobyl in June 1986.
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Construction crews build a containment wall around the damaged unit four reactor in August 1986.
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A doll remains in an evacuated village in Belarus near Chernobyl. Millions of people were exposed to dangerous radiation levels, and estimates of the final death toll from long-term health problems are as high as 200,000.
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