RICHMOND — A final decision has not been made, but preliminary information presented Tuesday strongly suggests that more than 15,000 mustard rounds at Blue Grass Army Depot will be exploded inside steel detonation chambers and not destroyed through a pilot plant under construction in Madison County.
A sampling of 96 mustard rounds X-rayed in May and June determined that 85 percent had at least a 30 percent solidification of mustard agent, or "heel," in the projectiles, said Rusty Fendick of the U.S. Army Chemical Materials Agency.
The presence of heel in the 155mm mustard shells at other facilities across the country has led to complications and delays in the destruction process because solidified agent is dfficult to remove.
Trying to remove that agent by hand poses a greater risk to workers than just exploding the rounds in steel vessels.
Minimizing the contact of workers with agent is a "cardinal rule," said Jeff Brubaker, site project manager for the pilot plant formally known as the Blue Grass Chemical Agent Destruction Pilot Plant.
The data presented Tuesday would not alter constuction plans for the pilot plant that is now more than 40 percent complete. That's because more than 85 percent of the Blue Grass stockpile contains agent other than mustard.
But "the preliminary data shows that the mustard rounds are in a condition that is very likely to require an alternative approach to the main facility," said Craig Williams, director of the Chemical Weapons Working Group, a watchdog organization based in Berea. "We have a little further way to go to make that determination."
Given what's known, Williams said "it's reasonable to assume" that the rounds will be exploded rather than destroyed at the pilot plant.
The data was presented at a quarterly meeting of the Kentucky Demilitarization Citizens' Advisory Commission and the Chemical Destruction Community Advisory Board. A final report about the X-ray assessment will be made public in October.
The possibility of exploding the mustard rounds has been known for several years. In 2008, problems were noted with some of the mustard projectiles in Tooele, Utah, where they were to be incinerated.
The liquid agent inside the 60-year-old shells had solidified into a tarlike consistency and could not be drained. In addition, workers couldn't remove the explosive element in each shell, known as the "burster."
The pilot plant will use a "fully automated process" using robots and machines designed to destroy the weapons. But the presence of heel complicates the process and increases the likelihood that workers would have to go in and manually deal with the problems.
"If we can't get the burster out, we might have to cut off the top of the projectile or something like that, and there's a risk of explosion in that type of operation," Brubaker said. "Or, if we can remove the explosive burster, then it's an issue of dealing with the 11.7 pounds of agent in each of these projectiles and how to deal with that."
The problems encountered in Tooele foreshadowed similar problems in Madison County because 65 percent of mustard lots at the Blue Grass Army Depot stockpile are identical to those in Utah.
As an alternative, Army officials suggested the use of EDTs or "explosive destruction technologies," which would not require disassembly of the munitions.
Exploding the mustard rounds would also demonstrate that the United States is making a "good faith effort" to destroy its chemical stockpiles.
The United States is obligated to dispose of its chemical weapons stockpile by 2012 under the terms of the International Chemical Weapons Convention Treaty, but the government has acknowledged that the deadline will not be met.
In addition, the Army has said it could potentially save eight months of destruction time at the pilot plant if all the mustard rounds could be destroyed by detonation in fixed steel chambers.
There are three commercial types of EDTs under consideration for use at Blue Grass. Local officials will learn more about two of those technologies used at Tooele and in Anniston, Ala., at a December meeting in Richmond. Anniston has already destroyed 2,500 mustard rounds using EDT. The equipment at Tooele is supposed to be operational sometime this fall.
In addition, Bechtel Parsons, the contractor building the pilot plant, is conducting a study of the three types of EDTs. The results of that study will be available in December.
Officials emphasized that people in the community will be briefed about any plan to implement detonation chambers at the depot. There is no specific timeline when that technology might begin, if it is, indeed, approved by federal and state officials. If all goes well, the pilot plant might be completed in 2015, Brubaker said. The destruction of weapons at Blue Grass will not begin until 2018, according to a previously released timeline. The destruction of weapons would be complete in 2021.
A formal recommendation on EDT at Blue Grass will be formulated and considered by the Citizens' Advisory Commission and the Chemical Destruction Community Advisory Board by March 2012, Williams said.
Just as community involvement was a "cornerstone" of the decision-making process for the pilot plant's technology, so it will be on the process for EDT, Brubaker said in a statement.
"We want everyone to be able to understand and provide feedback on every step of the decision-making process," Brubaker said in the statement.