Cryofracture

General Atomics is a leader in demilitarization technology, having developed and operated various demilitarization systems for destruction of obsolete weaponry since 1982. To date, GA’s Advanced Process System experts have safely destroyed via cryofracture more than 35,000 obsolete munitions.

Demilitarization is often complicated by the inability to access the energetics contained within the munitions. Thermal treatment can easily destroy energetics if they are unconfined, but thermal treatment of confined energetics can lead to high-order detonations and associated equipment damage and potential personnel injury.
GA has refined the use of cryofracture technology that utilizes liquid nitrogen at -320°F to cool the munition body to below its embrittlement temperature. The cooled bodies can then be fractured in a hydraulic press, thus accessing the energetics and rendering them safe for thermal destruction.

The items are typically placed on munition-specific racks and submerged in a bath of liquid nitrogen. Depending on the munition type, the cooling time may vary from 10-30 minutes. The munitions are then placed in a hydraulic press, either individually (for larger munitions) or in specifically-arranged groups (for smaller munitions), and compressed until the munition body has fractured. The munition debris is then transferred to a thermal treatment system for final destruction of the energetics. For an additional level of safety, all material transfers are performed using either remotely-controlled robotics or automated conveyor systems.

Among the 35,000-plus obsolete munitions GA has cryofractured include 8-inch projectiles, M23 land mines, Area Denial Artillery Munition (ADAM) mines, 40-mm cartridge rounds, fuzes, bursters and hand grenades.

GA has constructed and operated cryofracture facilities at Yuma Proving Ground (Arizona) and McAlester Army Ammunition Plant (Oklahoma). A transportable system has been sited at Crane Army Ammunition Activity (CAAA) in Indiana, and a test system has been located at Tooele Army Depot (Utah). Transportable cryofracture systems are used for remote sites or where permanent installations are impractical. Portable systems offer the advantages of ready mobility to multiple storage sites and reduced packaging and transportation costs, since destruction can take place at the current storage location.