The Pueblo Chemical Agent-Destruction Pilot Plant, or PCAPP, is now in the Pilot Testing phase and is currently destroying the chemical weapons stockpile stored at the U.S. Army Pueblo Chemical Depot, or PCD. A two-step technology, neutralization followed by biotreatment, is the process selected to destroy the large majority of the stockpile. However, a small number of the weapons pose a problem for the main plant’s automated equipment to process, requiring the selection and deployment of an additional method, the Explosive Destruction System, or EDS, to augment PCAPP.
Q. What technology is being used at PCAPP to safely destroy chemical weapons?
A. The main facility is using neutralization followed by biotreatment.
During the neutralization process, munitions will be taken apart and energetics (explosives and propellants) will be removed. The mustard agent will be drained and the munitions bodies rinsed. The agent will then be mixed vigorously with warm water and sodium hydroxide, which destroys the agent. The resulting product, known as hydrolysate, is held and tested to ensure agent destruction before proceeding to a secondary process known as biotreatment, where ordinary sewage-treatment-type bacteria will further break down the hydrolysate into carbon dioxide, water and minerals.
Q. What technology is used by PCAPP EDS?
A. PCAPP EDS uses neutralization.
PCAPP EDS uses cutting charges to explosively access the mustard agent inside the munition. Operators add neutralization chemicals to destroy the agent. The detonation of the cutting charges also eliminates the explosive components of the munition. A heavy sealed stainless-steel vessel contains the blast, vapor and fragments from this process. Before the vessel is reopened, elimination of the chemical agent is confirmed by sampling residual liquid and air from the interior of the vessel.
Q. Why is PCAPP EDS necessary?
A. It is needed to destroy “overpacks” and “rejects” that pose a problem to process in the main plant.
“Overpack” refers to chemical munitions that have leaked or were sampled in the past to determine the condition of the mustard agent. In both instances, operators placed these munitions in air-tight sealed canisters, or “overpacks,” for continued safe storage. PCD stored more than 500 overpacked chemical munitions that have since been destroyed by the EDS. “Reject” chemical munitions have conditions that pose difficulties for automated processing. These munitions will also be destroyed using the PCAPP EDS process. Out of PCD’s total stockpile of more than 780,000 munitions, about 800 additional “rejects” are anticipated.