Excerpt - LAS VEGAS (AP) - U.S. and British government scientists performed an underground nuclear experiment, short of a nuclear blast, Tuesday at the Nevada Test Site, the National Nuclear Security Administration said. Scientists for the first time posted a nearly eight minute video Web log of preparations for the subcritical experiment. The operation, dubbed "Krakatau," involved detonating high explosives around a radioactive material in a vault about 1,000 feet below ground at a remote part of the desert testing range. "This was the first time this much video was made available before the experiment," said Kevin Rohrer, a Nevada...