Subcritical nuclear test scheduled in 2004

Monday, Aug. 25, 2003 | 11:37 a.m.

Federal scientists are preparing to conduct a nuclear materials experiment at the Nevada Test Site in 2004, the National Nuclear Security Administration said.

The National Nuclear Security Administration announced Friday that next year it will conduct a subcritical experiment, named Unicorn, in a horizontal underground cavern about 1,000 feet beneath the Test Site, roughly 85 miles northwest of Las Vegas.

Subcritical experiments involve exposing tiny amounts of nuclear materials to high explosives. The resulting blast stops short of producing a nuclear chain reaction. Subcritical experiments allow scientists to study how plutonium and other radioactive materials behave when detonated with explosives.

The subcritical experiments are designed to test the skills of U.S. nuclear weapons experts, as well as the materials contained in the U.S. nuclear arsenal.

Unicorn will be the nation's 20th subcritical experiment since the program began in 1997. The most recent such experiment was called Rocco, conducted on Sept. 26, 2002.

The exact date for next year's experiment has not been set, officials said. Initial site preparation for the experiment is under way, Darwin Morgan, an administration spokesman said.

"This activity, and the means for emplacement of the experimental hardware into the vertical hole, will appear visually similar to those employed in underground nuclear tests conducted prior to the 1992 moratorium," the administration's statement said.

Former President George Bush imposed a moratorium on nuclear testing in September 1992.

But current Bush administration officials said last year that they wanted the Test Site to be prepared to resume full-scale nuclear tests, if necessary, within 18 months, roughly half the time it would take to prepare for such experiments today.