A worker of the Belarussian radiation ecology reserve prepares skins from wolves, which were killed in the 30 km (18 miles) exclusion zone around the Chernobyl nuclear reactor, in Khoiniki, some 350 km (217.4 miles) southeast of Minsk, April 7, 2006. Ukraine and Belarus mark this year the 20th anniversary of the Chernobyl nuclear disaster, considered the worst accident in the history of nuclear power, which resulted in the evacuation of roughly 200,000 people. REUTERS/Vasily Fedosenko