Objective

The Department of Defense (DoD) faces many environmental and legal issues involving the demilitarization of obsolete, excess, and off-spec energetic materials and assembled munitions. The current DoD stockpile of energetic materials that must be destroyed is about 700,000 tons, and it increases by approximately 60,000 tons per year. Alternatives to open burning/open detonation (OB/OD) are necessary to comply with increasingly stringent regulations.

The objective of this project was to develop an innovative alternative technology to replace OB/OD operations by reacting bulk energetic materials with a hypergolic chemical, which neutralizes the energetic materials in a controlled manner and without detonation.

Technical Approach

The following two approaches have been used to develop effective reagents for the pre-treatment of explosives: (1) relatively low-temperature controlled exothermic reactions in a liquid-phase environment and (2) solid-state controlled hypergolic reactions. These reactions are not well understood, and the focus of the effort has been to fully understand the underlying chemistry.

Results

When employed as hypergolic reactants, ethanolamine and diethylenetriamine each exhibited controlled exothermic reactions with trinitrotoluene (TNT) at room temperature in a variety of solvents and in the solid state. Diethylenetriamine also reacted with hexahydro-trinitrotriazine (RDX) exothermically in the temperature range of 90-140EC, but in a safe and controlled manner. The energy release from the reaction with TNT can be used to initiate the reaction with RDX and enable deactivation of the explosive material known as Composition B (which is composed of 40 percent TNT, 59 percent RDX, and 1 percent wax). Detonation never has occurred in numerous field tests even though the explosive (up to 100 g) was confined during the decomposition process. Differential scanning calorimetry has been used to show that TNT is destroyed and an intermediate compound is formed during these hypergolic reactions. This project was completed in FY 2001.

Benefits

This project will provide the DoD and the Department of Energy with a reliable and safe alternative to OB/OD, based on the chemical breakdown of the energetic materials without detonation. There also may exist the potential for reuse of the byproducts. Conventional chemical processing equipment is adequate for full-scale implementation of this technology.