Pentagon Clarifies Nevada Intent

By Ann Scott Tyson
Washington Post Staff Writer
Friday, April 7, 2006

Pentagon officials apologized to members of Congress yesterday for generating fears about an unusual military experiment to detonate 700 tons of explosives in the Nevada desert in June, and they said the test was not designed to simulate a low-yield nuclear explosion, even though government budget documents had described it that way.

Officials said the test, code-named Divine Strake, is part of research to "determine the potential for future non-nuclear concepts" -- such as high-energy weapons or the simultaneous use of multiple conventional bombs to destroy deeply buried and fortified military targets. They said the budget documents' references to simulating a nuclear explosion were in error.

Last week James Tegnelia, director of the Pentagon's Defense Threat Reduction Agency, described the test to defense reporters as a massive blast that would create a "mushroom cloud" of dust over Nevada. Tegnelia offered his regrets for the remark when he met yesterday on Capitol Hill with Nevada lawmakers, who voiced concern about safety issues, environmental impact and their lack of full knowledge about the test.

"While I am glad Dr. Tegnelia took this opportunity to apologize for causing alarm with his mushroom-cloud comment, the real purpose of this meeting was to ensure that . . . there is no safety threat to southern Nevada residents," Rep. Shelley Berkley (D-Nev.) said after meeting with Tegnelia.

The test is scheduled for June 2 about 90 miles northwest of Las Vegas in a high desert valley bounded by mountains in the Energy Department's Nevada Test Site. The test will ignite the equivalent of 593 tons of TNT in a 36-foot-deep hole near a tunnel in order to measure the ground shock and damage created at different levels of depth, according to Tegnelia and an official environmental assessment. The test is aimed at providing tools to better understand how different types of weapons would work against fortified underground targets -- such as military headquarters, biological or chemical weapons stockpiles, and long-range missiles -- that the Pentagon says are proliferating among potential adversaries around the world.

The controversy over the test was fueled this week by conflicting statements from DTRA as to whether research from the blast had applications only to conventional weapons, or also to nuclear devices.

Tegnelia has consistently described the test as applying solely to conventional weapons. "The purpose of the test is to advance conventional weapons," he said in an interview Wednesday.

He acknowledged that it would not be feasible for the U.S. military to create or deliver a single conventional bomb large enough to duplicate Divine Strake's huge blast -- and that the only U.S. weapon today capable of destroying such a tunnel would be a nuclear device. "If you had to do it today . . . and you have to break this tunnel, and you're going to have to do it with one pass and one weapon, the physics says the only way you can do it is with a nuclear weapon."

But he said that the test could help determine the damage if an underground target were struck simultaneously with multiple conventional bombs. "You can't do it with one, but you might be able to do it with multiple efforts," he said.

Another purpose of the test is to gauge the potential of "advanced conventional explosives with much higher energy" or "high energetic explosives," said DTRA spokeswoman Irene Smith.

Confusion over whether the test was related to nuclear research was created on Tuesday, when DTRA officials confirmed that Divine Strake was the same as the "tunnel target defeat" test described in 2005 and 2006 budget documents. Those documents said it was designed to "simulate a low yield nuclear weapon ground shock environment," and help the military select "the smallest proper nuclear yield necessary to destroy underground facilities."

On Wednesday, however, Smith said that, although DTRA was not "disavowing" the budget documents, "things change. That has changed and the wording got left in" improperly, she said, meaning the references to "nuclear." Tegnelia's office did not respond to requests for comment yesterday.

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