Facts: Munitions Washout System

The last chemical munition in the declared U.S. stockpile was destroyed July 7, 2023. The facilities are in the closure phase and are following procedures outlined in U.S. Public Law and the relevant environmental permits. Please visit https://www.peoacwa.army.mil/pcapp/ for the most recent information.

Munitions entering the Agent Processing Building are processed in the Munitions Washout System, which consists of two processing lines with four Improved Cavity Access Machines (ICAMs) each. Two ICAMs are pictured.
Munitions entering the Agent Processing Building are processed in the Munitions Washout System, which consists of two processing lines with four Improved Cavity Access Machines (ICAMs) each. Two ICAMs are pictured.

The Pueblo Chemical Agent-Destruction Pilot Plant (PCAPP) is safely destroying chemical weapons stored at the U.S. Army Pueblo Chemical DepotNeutralization followed by biotreatment is used to destroy the mustard agent contained in 4.2-inch mortar rounds.

The Munitions Washout System (MWS) consists of two Improved Cavity Access Machine (ICAM) arrays, each designed to process 4.2-inch mortar rounds. The entire process is safely monitored and controlled by operators in a remote station.

For the 4.2-inch mortar rounds, the MWS process is slightly different than the CAMs used during the 155mm and 105mm campaigns. The MWS robotic arm places a mortar round in an upright position in the ICAM.

  • Step 1: The burster wells are removed and rinsed to remove residual mustard agent. Holes are subsequently punched into the burster well to allow pressure to dissipate during subsequent processing..
  • Step 2: The ICAM takes the mortar round to a wash water station, where agent is first drained from the mortar round. Wash water is then sprayed inside the mortar round to rinse out any residual agent. During washing, the ICAM lifts and rotates the mortar round to ensure agent removal from all interior surfaces. Chemical agent and rinse water are piped to another area of the plant where the agent is neutralized. After the rinse is complete, the punched burster well is reinserted into the mortar body. The robot then removes the mortar shell from the ICAM and transfers it to the Munitions Treatment Unit for final processing.

After the chemical agent and rinse water from the MWS are neutralized, the resulting hydrolysate is piped to another area for subsequent biotreatment processing. The entire process is monitored by Control Room operators to ensure safe handling and destruction of the munitions and agent.

A portion of the mortar rounds are being destroyed using Static Detonation Chamber, or SDC, units. The SDC complex remains essential for the ability to process munitions regardless of their configuration or physical condition.

The Program Executive Office, Assembled Chemical Weapons Alternatives is responsible for completing stockpile destruction operations by the Chemical Weapons Convention treaty commitment of Sept. 30, 2023.

To learn more, view the PCAPP Munitions Washout System video.

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