David Puttnam's decision to resign as chairman of Columbia Pictures may have damaged prospects for "Chernobyl," his co-production with Stanley Kramer. Puttnam visited Moscow with Kramer in July to attend the Moscow Film Festival and make preparations to film the story of the Soviet nuclear disaster. Soviet writer Alex Adamovich--asked to co-write the film--is expected to arrive in Hollywood next week, according to Daily Variety. Puttnam told the Hollywood trade paper that he has his doubts. "I frankly don't know about its future," he told Variety. Gary Martin, executive vice president and executive production manager for Columbia, was not available for comment.