Explain This: Subcritical experiments

Explain This: Subcritical experiments

by Frank von Hippel

Earlier this month, the US National Nuclear Security Administration (NNSA) announced that it had conducted a subcritical experiment with plutonium in an underground tunnel 300 meters below the Nevada National Security Site (formerly, the Nevada Test Site), about 65 miles northwest of Las Vegas. Named Pollux, it was the 27th such experiment that the United States has conducted since it ended test nuclear explosions in 1992.http://www.thebulletin.org/web-edition/features/explain-subcritical-experiments