August 25, 2000

B-2 successfully drops improved bunker buster bomb

------------------------------------------------------------------------

by Senior Airman Adam Stump

354th Fighter Wing Public Affairs

EIELSON AIR FORCE BASE, Alaska (PACAFNS) -- A B-2 Spirit bomber dropped two B61-11 bomb shells to test their improved ground penetration capability March 17 at the Stuart Creek Impact Area, 35 miles southeast of Fairbanks.

The tests here were designed to measure the nuclear bomb casing's penetration into frozen soil and the survivability of the weapon's internal components.

These were the final two tests needed to certify the weapon system as operational.

A team excavated the two unexploded dummy bombs and took careful measurements of their angles and depth of penetration into the soil, which were six and 10 feet, according to Ellsworth Rolfs, a B61-11 program test manager. The shells were sent back to Sandia National Laboratories in New Mexico for full analysis of how the simulated internal components fared in the impact.

The B61-11 is a new modification to a nuclear bomb that has been in the Air Force inventory since the 1960s. The bomb can be used against a variety of enemy targets, including deeply buried underground command posts and weapons storage facilities. A new case design lets it penetrate the ground to a depth of 15 to 25 feet, where the nuclear bomb would then detonate.

The bomb cases contained simulated nuclear components made of depleted uranium, a heavy metal that closely approximates the physical characteristics of enriched uranium, without the hazards associated with weapons-grade material. Use of depleted uranium allowed scientists to realistically assess the effects of impact.

Rolfs stressed that the depleted uranium was encased in the new exterior shell, which proved extremely durable in the tests. Although solid depleted uranium is a low-level radiation hazard, emitting only alpha radiation that cannot even penetrate clothing or the skin, it can present a health hazard if physically ingested into the body.

Ingestion of depleted uranium is normally associated with explosive or flammable situations, where the substance can potentially be turned into dust or vapor and then inhaled.

Rolfs was quick to point out that the depleted uranium aboard the dummy bombs was in a solid state (like a chunk of steel or any other metal), which virtually eliminated the chances for ingestion.

"The test unit casing didn't rupture in any of our tests, including drops through concrete from 40,000 feet," he said. "We fully recovered all test units 100 percent intact."

Even though the B61-11 survived being dropped through concrete, the Air Force had trained emergency response teams standing by to handle any unforeseen problems, said Jim Nolke, chief environmental planner for the 354th Civil Engineer Squadron. He added the Air Force had extensively studied the proposed test, and were confident the test would not impact Alaska's people, wildlife or environment.

The Air Force worked closely with Alaska environmental officials to obtain all required permits and ensure full compliance with the law.

After the two units were recovered, the Air Force filled in the holes made by the impact, and leveled the ground back to its pre-test condition in accordance with federal law, said Nolke.

-30-A B-2 Spirit Bomber from Whiteman Air Force Base, Mo., drops a B61-11 bomb casing. (Courtesy photo)