Nuclear material won't fuel the June 2 blast. And air currents won't carry contaminated fallout into Utah. Nor will the massive explosion be practice for future nuclear tests.
Officials from the U.S. Energy Department's Nevada Test Site and the Pentagon's Defense Threat Reduction Agency (DTRA) insisted on these points Wednesday. But aides from Utah congressional offices, fresh from touring the test site, reserved judgment until they get more information.
"We knew going in there would be more questions," said Alyson Heyrend, spokeswoman for U.S. Rep. Jim Matheson, who viewed the site along with other congressional aides from Utah and Nevada.
"Divine Strake," as the Pentagon has dubbed the test, is scheduled for a high-desert hilltop about an hour-and-a-half's drive north of Las Vegas.
Its goal: to show the ripple effects, called "shock waves," of an explosion above a tunnel - the sort of bunker where military leaders of an enemy nation might hide weapons of mass destruction, key equipment or themselves.
DTRA will detonate 700 tons - roughly 37 truckloads - of an explosive stew developed in Utah, ammonium nitrate and No. 2 fuel oil, in a 37-foot-deep, 32-foot-diameter pit. The pit is about 100 feet above a 1,000-foot tunnel.
Scientists have posted super-high-speed cameras in the tunnel and threaded more than 500 sensors in the surrounding rock to measure the destructive forces from the blast above.
Test results will help them double-check their computer estimates and determine how much explosive force is needed to damage a similar bunker - maybe one in China, North Korea or Iran. DTRA's Douglas J. Bruder said either a nuclear or conventional bomb could be used to trigger the sort of explosion being studied.
"There is no relationship between this test and any new nuclear weapon," he told reporters.
Bruder's agency focuses on countering chemical, biological and nuclear weapons. He added: "This experiment will allow us to test any current or future weapon against this kind of facility."
Utahns Steve Erickson and Peter Litster have joined with a group of Western Shoshone Indians going to federal court to try to stop the June 2 test. Tribal members say the test would be another violation of their treaty with the U.S. government. Like other Utahns, they fear Divine Strake is leading up to nuclear "bunker buster" bomb tests.
Government officials declined to comment on the case, but Erickson said the Pentagon has failed to show that Utahns will not once again find themselves downwind of toxic nuclear material.
"It's gigantic, and it's going to send a big cloud into the air," Erickson said of the test. "That's our biggest worry about this: Here we go again."
People even as far away as northern Utah and Idaho say the government's testing programs in the 1950s and 1960s exposed them to fallout, which caused illness, cancer and death.
Matheson's father, the late Utah Gov. Scott Matheson, died from a downwind cancer. And, U.S. Sen. Orrin Hatch helped establish a federal fund, which has disbursed $1 billion to downwinders and their families.
Both Hatch, a Utah Republican, and Matheson, a Utah Democrat, have questioned how Divine Strake might affect Utahns and their environment.
Aides emerged from their tour Wednesday with many of those questions still unanswered.
A draft environmental assessment of Divine Strake contains no details on the computer projections of how much dirt will shoot into the air, how contaminated that dirt is from past nuclear tests and exactly where the cloud is expected to drift.
But Linda Cohn, who plans to finish the environmental review in the next few days, said she expects the test to be "ho-hum" in terms of health and environmental effects. She said she had "no idea" why some people are worried about it.
"There is literally no way this experiment can pick up radioactive contamination," she said, "because it does not exist here."
Underground nuclear tests were conducted in a tunnel just over a mile away. Above-ground tests took place over four and six miles to the north from the Divine Strake test site.