Unicorn, a subcritical experiment, was successfully conducted at 11:00 a.m. on August 30, 2006, at the Nevada Test Site. Los Alamos National Laboratory conducted the experiment to gather scientific data that provides crucial information to maintain the safety and reliability of the nation's nuclear weapons without having to conduct underground nuclear tests.
Unicorn was the 23rd subcritical experiment to date. The previous subcritical experiment, Krakatau, was conducted on February 23, 2006.
Subcritical experiments examine the behavior of plutonium as it is strongly shocked by forces produced by chemical high explosives. Subcritical experiments produce essential scientific data and technical information used to help maintain the safety and reliability of the nuclear weapons stockpile. The experiments are subcritical; that is, no critical mass is formed and no self-sustaining nuclear chain reaction can occur; thus, there is no nuclear explosion.