Workers at the Pueblo Chemical Agent-Destruction Pilot Plant have begun erecting a structure to cover the first Static Detonation Chamber.

“This is real progress,” said Matt Crookshanks, manager, SDC. “Enclosed structures will allow us to continue final installation activities of the SDCs in inclement weather, open work fronts for various piping and electrical installation activities, and will protect the equipment and coatings during the (assembly) phase of the project.”

In early December, Pueblo County joined the Colorado Department of Health and Environment in issuing temporary authorizations allowing canopies to be built that will cover the plant’s SDC units.

The tension fabric coverings, also known as Sprung structures, arrived disassembled in late September on two flatbed freight trucks. They will shelter the SDC units, three of which will augment the main plant by destroying munitions not suitable for its automated process.

An SDC uses electrically generated high-temperature heat to detonate or deflagrate the projectiles. The mustard agent and energetics are destroyed by thermal decomposition. Off-gases are treated by an air-pollution equipment system. The 4.2-inch mortar rounds cannot be processed safely in the plant’s disassembly and drainage system and will be processed through the SDC units.

In addition to the environmental enclosure, the governments’ temporary authorizations also allow for a filtration system.

Crookshanks said the team pre-assembled as much of the structure as possible on the ground before the temporary authorization was approved to reduce the amount of elevated work needed and streamline productivity. The first structure is expected to be complete by the end of January 2020.

A similar enclosure covered the U.S. Army’s Explosive Destruction System, which was used from the start of agent operations at PCAPP in 2015 to the end of 2018 to destroy munitions that weren’t in good condition to go through the main plant.