PBS - Secrets of the Dead: World's Biggest Bomb (2011)

Beginning in the 1950s, American and Soviet scientists engaged in a dangerous race to see who could build and detonate the world's largest bomb. The results exceeded all expectations about how big a bomb could be built. This is an epic story where the United States led the way, but then left the field clear for the Soviet Union to break all records. The story of the race to build the World's Biggest Bomb has never been fully told.