Those living in the lush green mountains of Gwynedd, Wales, have a word for the chill winds that sweep from the East - Gwynt traed y meirw, which translates as "wind from the feet of the dead". So muses Gwyn Roberts, who, on April 26, 1986, was a young farmer of 26 years old, diligently filling out his diary with notes on the weather when a catastrophe unfolded more than 2,000 miles away. Little did Gwyn know then that an explosion at the Chernobyl Nuclear Power Plant in the Ukrainian SSR,