Los Alamos To Conduct 'Subcritical' Nuke Experiment in Nevada
The Associated Press
LOS ALAMOS — Los Alamos National Laboratory is planning its eighth subcritical nuclear experiment, dubbed "Armando," at the Nevada Test Site this spring.
Los Alamos researchers, touring the site with reporters this past week, said the experiment — the 21st of a series — will use bomb-grade plutonium but that the configuration of the explosives will prevent a full-fledged nuclear explosion.
The detonation will take place inside a high-strength steel spherical vessel to contain the explosion. The 3-foot vessel, which has ports that allow for X-ray imaging and other diagnostics, rests in a sealed chamber about 1,000 feet beneath the Nevada desert 80 miles north of Las Vegas, Nev.
The United States banned nuclear testing in 1993, so such experiments are as close to a thermonuclear weapon ignition as the nation can get.
The U.S. Department of Energy conducted the last of 1,054 nuclear tests on Sept. 23, 1992, then moved on to what it calls "science-based stockpile stewardship." Los Alamos now uses experimental data to check computer codes that describe the behavior of nuclear weapons, Los Alamos spokesman Jim Danneskiold said.
Los Alamos kicked off its subcritical experiments in 1997.
Raffi Papazian, the lab's director of operations at the Nevada Test Site, said subcritical tests help maintain expertise and equipment in case the United States decides to restart nuclear tests.
The first experiments in the series were designed to answer basic scientific questions about the nature and behavior of plutonium, the radioactive metal at the core of a modern thermonuclear bomb, Papazian said.
Armando is the third, and most advanced, in a series geared toward certifying nuclear pits — plutonium triggers for bombs — now manufactured at Los Alamos, Papazian said.
Ultimately, the experiments should help scientists understand such things as how plutonium holds up under extreme shock, he said.
"It tells you how strong plutonium is, so that when you feed it into a computer, you have the right number," he said.
Pits were made for decades at the Rocky Flats plant near Denver, but it closed in 1989. In 1996, the DOE selected Los Alamos to re-establish the capability, starting with the W-88 warhead carried by Trident submarines. Congress early this year cut funding for a proposed plutonium trigger factory, solidifying Los Alamos as the nation's primary pit manufacturer.
"What we are exploring today is the difference between what we are producing at Los Alamos, which is cast plutonium, and what was produced at Rocky Flats, which was wrought plutonium," Papazian said.
Researchers hope the results "will show that everything is fine, which means a new-built pit functions just like an old pit," he said.
The first pit to meet specifications came out last year, and the lab has produced several more since. The next step is certifying that the pits will work before putting them into the stockpile.
The first fully certified pit is expected to be ready by 2007.
Papazian said he didn't know how much Armando will cost. Past subcritical experiments ranged from $20 million to $30 million.
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