Sandia LabNews

Sandia's Explosive Destruction System destroys sarin bomblets at Rocky Mountain Arsenal

Sandia’s Explosive Destruction System successfully destroyed six sarin-filled bomblets recovered at the Rocky Mountain Arsenal in Colorado.

The self-contained unit, designed and built by Sandia, safely neutralized the last of the nerve agent-containing bomblets (each about the size of a grapefruit) on Feb. 10. The six bomblets were found in October during Superfund cleanup of the site, which is also a wildlife refuge. They had been designed for a 1950s-era missile called "Honest John," and were never used.

"The highlights were the first successful destruction and the sixth successful destruction," says John Rosenow (8118), a field test engineer who has traveled with the system since September 1999. "There was a lot of concern by local citizens. After the first shot Jan. 28, the public seemed much happier."

As the first couple of cars approached the arsenal at 6:30 the morning of the last shot, the drivers saw a bright þash from a power line that had broken in the minus 18-degree weather. The operation "hardly missed a beat" despite this unforeseen happenstance, which was fixed within two hours, John says.

Once the operation was successfully completed, "we were ecstatic," says Al McDonald (8118), whose staff led the EDS design. "Here was a way for Sandia to be involved in a national problem and work with the Army to get it up and running. It made everybody very glad and happy to contribute to a solution." The US is committed to dispose of all chemical munitions by 2007.

The EDS (Lab News, Aug. 27, 1999) was developed by Sandia for the Army’s Non-Stockpile Chemical Materiel Program. It is designed to safely dispose of old munitions deemed too unstable to transport. The system can be pulled by trailer to sites where these munitions are recovered. The munitions are placed within an air-tight chamber, where their metal shells are opened with an explosive charge. The contents are then neutralized with caustic chemicals. An alternative disposal method, open burn/open detonation, involves packing explosives around the munition to incinerate the contents. However, the lack of containment has posed concerns for the public.

"You don’t want to be breaking anybody’s window, even if you do burn everything that’s there," says Tim Shepodd (8722), EDS lead chemist.

As an extra reassurance, at the Rocky Mountain Arsenal the trailer carrying the EDS was placed within a large building equipped with an air filter, Tim says. Also, the process is closely monitored through sampling. "We never open the door until we see that both the liquid and atmosphere are completely neutralized."

Acting program manager John Didlake calls the Denver operation a defining moment. "We built up a bunch of confidence," he says, "with the public, the EPA, and the Army."

When the bomblets were found, the EDS had been undergoing field testing at the United Kingdom’s Defence Evaluation and Research Agency in Porton Down, England. The tests, spread over 13 months, primarily involved destroying WW I and WW II-era munitions containing phosgene gas or mustard. In anticipation of the Colorado project, one test also included destruction of a 1.3-pound bottle of sarin fabricated for this purpose.

John Rosenow says he really enjoyed working with the British crew, two of whom came to Colorado for the bomblet destruction. Both the British safety officer and the lead crew operator helped train the Army crew that handled the operation (which was pre-approved by a 25-person safety team).

"They felt like they were the cavalry, they had trained for this," John Didlake says.

The current system will undergo more operational testing at Aberdeen Proving Ground in Maryland. Meanwhile, Sandia is building two more systems of the same size (a three-foot-long chamber, pulled on a 30-foot trailer), as well as a third with larger capacity.

Rick Moehrle (8118), acting lead engineer on the new system, says the next models will incorporate some design improvements, such as a trailer layout that provides more space for workers to move about and an electric motor-rotary agitation system to mix the chemicals.

From New Mexico, Jerry Stoþeth of Explosives Applications Dept. 15322 has led the development of the explosive munition opening system. The system includes a metal shield to suppress fragments within the reusable containment chamber, shaped charges to cut open the item being destroyed, and a firing system to detonate the charges.