Opponents of the Divine Strake non-nuclear explosion planned for the Nevada Test Site claimed Wednesday that the federal government is using an inappropriate model to determine the fallout from the experiment.

During a status hearing Wednesday morning, Robert Hager, a Reno attorney representing the "downwinders" in Nye County and Utah said the government's fallout prediction is off base.

"It's a military model that assesses visibility. It has nothing to do with health," Hager said of the government's model.

Hager said that if particles 10 microns in size are blown 10,000 feet into the air, they will settle as far as 1,250 miles away from the test site. Particles smaller than 1 micron are not affected by gravity and will remain suspended in the atmosphere indefinitely.

"That's why we have plutonium from the test site in glaciers in Switzerland," Hager said, referring to tests performed previously at the site 85 miles northwest of Las Vegas.

Hager said the explosion is an "international issue" because particles could reach Mexico and Canada.

Representatives of the Defense Threat Reduction Agency, formerly the Defense Nuclear Agency, had no comment on the hearing.

A new status hearing was scheduled for March 1.

The test was originally planned for June 2006 but was postponed after members of the Winnemucca Indian Colony and downwinders took legal action to force the government to show that the blast and its mushroom cloud would not disperse radioactive materials.

The concerns arise from questions about whether radiological contamination from past nuclear tests could be sent into the atmosphere.

The explosion is a test designed to explore futuristic conventional bombs and fine-tune the capabilities of existing nuclear weapons for destroying deep tunnels where an enemy might store weapons of mass destruction.

The government agreed to give opponents a 30-day notice between the announcement of the explosion and the actual blast.