Army:  Tests show that new treatment process works
Associated Press
Fri, September 2, 2005

The Army said Thursday that changes a contractor made to its process of neutralizing a deadly nerve agent stored in western Indiana significantly reduced the flammability of the waste produced when the chemical weapon is destroyed.

Jeff Brubaker, the Army's site project manager at the Newport Chemical Depot, said the tweaked process of destroying the VX nerve agent yielded wastewater with flash points above 141 degrees, with some samples having flash points greater than 200 degrees.

The flash point is the lowest temperature at which the vapor of a combustible liquid can be made to ignite.In contrast, the flash points of the waste, called hydrolysate, produced by the destruction of the initial batches of the nerve agent was between 68 and 88 degrees, posing questions about the feasibility of the Army's plans to ship the waste to New Jersey for treatment and disposal.

"Our analysis here shows that we were capable and successful in processing nonflammable hydrolysate," Brubaker said Thursday.

He said the Army's contractor, Parsons Technology Inc., will send samples of the hydrolysate to a certified, private laboratory -- and possibly a second lab -- for independent analyses.

In May, workers at the Newport Chemical Agency Disposal Facility 30 miles north of Terre Haute, Ind., began destroying more than 250,000 gallons of VX using a chemical neutralization process.

The liquid VX is injected into a reactor where it is mixed with water and sodium hydroxide heated to about 195 degrees for hours to destroy the nerve agent's chemical bonds. The result of the VX destruction was a caustic wastewater called hydrolysate.

Officials halted the project in June after a leak caused about 30 gallons of VX and hydrolysate to spill into a sealed area.Subsequent testing on samples of the about 3,300 gallons of hydrolysate the project has produced to date found its flammability levels much higher than what laboratory tests predicted.

Brubaker said Parsons engineers determined that the problem was the unexpected accumulation of a chemical called diisopropylamine, or DIPA, that became trapped in the depot's two reactors during the neutralization process.

They modified how it was processed, and last Friday and on Tuesday, two 180-gallon batches of VX were neutralized in one of the reactors, producing hydrolysate with the lower flash points.

Brubaker said Parsons engineers will work to continue to refine their efforts to reduce DIPA levels by running small batches of VX in one of the reactors.

Meanwhile, work is progressing on replacing Teflon diaphragms in the other reactor's valves with a type of ball bearing valve system that is expected to be better able to withstand the caustic material coursing through the reactor.

Brubaker said that the leak in June was caused by the degradation of a polymer-based diaphragm in the valves. Those were subsequently replaced with a stronger Teflon material.