Military explosives environment

RDX is a widely used military explosive. It is a synthetic compound and is not known to exist in nature. Effluents and emissions from Army ammunition plants are responsible for the release of RDX into the environment. When released to the atmosphere, RDX may be removed by reaction with photochemically generated hydroxyl radicals (half-life =1.5 hours). When released to water, RDX is subject to photolysis (half-life = 9-13 hours). Photoproducts include formaldehyde and nitrosamines. 

It is clear that any assessment of the bioaccumulation, bioconcentration, and biomagnification of military explosives must consider the behavior of the parent compound and all potential metabolites, whether they are formed within the organism or in the soil/water environment. This chapter will therefore begin discussions with descriptions of the chemical transformations that commonly occur with these compounds. 

Pollution of soils and waters by human activities is an important and widespread problem. This pollution by, organic and inorganic substances can affect individual organisms, human populations, and ecosystems, each in its own unique way. In particular former military installations, often used for weapons production and nuclear power plants represent a ongoing and substantial threat to environment and human health because of the specific pollutants that can be released Solvents, explosives, fuels, radionuclides, heavy metals, and metalloids all have been identified in the environment around these installations. Remediation technologies for these contaminated sites have been developed based on conventional systems utilising physical and chemical treatments, such as excavation and incineration, pump-and-treat methods, ultraviolet oxidation, soil washing, etc. 

Tetryl may be released to the air, water, and soil when old stores of the explosive ate destroyed by exploding or burning. However, tetryl has not been measured in air during any of these activities. Tetryl that was manufactured or stored at military installations, like Army ammunition plants, may still be present in the soil and water at or around these sites. Tetryl is not likely to evaporate into air from water or soil surfaces. However, tetryl may be present in air associated with dust from these sites. Tetryl appears to break-down rapidly in some soils. Picric acid, is one of the break down products of tetryl in soil. Tetryl probably does not easily travel from soil to groundwater. Erosion of soil from contaminated sites may release tetryl to nearby surface water. Once it is in the water, tetryl may dissolve or associate with small particles of suspended solids, sediments, or organic debris. Some of these particles will settle to the bottom. Tetryl breaks down rapidly in sunlit rivers and lakes but much more slowly in groundwater. It is not known whether tetryl will build up in fish, plants, or land animals. See Chapters 4 and 5 for more information on tetryl in the environment. 

Rocket Motor and Fuel Disposal With the reduction of military forces in the United States and worldwide, rocket motors are being removed from service and reduced in number. The motors are being shipped to munitions depots for storage and for disposal. The disposal method presently used is open bum/open detonation, which can result in explosions that scatter motor parts and contaminate the environment with unbumed propellant. An effective and environmentally sound alternative to open bum/open detonation is required. 

Letzel S et al., Exposure to nitroaromatic explosives and health effects during disposal of military waste, Occup. Environ. Med., 60,483, 2003. 

In a military or industrial setting, nitrogen dioxide occurs in the presence of electric arcs or other high-temperature welding or burning processes, and particularly where nitrate-based explosives are used in enclosed environments (such as tanks and ships). Diesel engine exhaust also contains substantial quantities of nitrogen dioxide.36 39... 

Cyclic nitramines such as RDX or cyclotetra-methylenetetranitramine (HMX) are widely used in military composites such as Composition B (TNT and RDX) and Composition C-4 (US) or PE-4 (British) and in commercial blasting explosives such as Semtex (a Czech-made mining explosive). HMX is present as a by-product in RDX made by the Bach-mann process and has applications in explosives to be used in high-temperature environments. Chemical tests for RDX include the J-Acid and thymol tests. A number of TLC systems for RDX and HMX have been reported. With adequate sample, IR identification of the pure material in a micro-potassium bromide pellet is simple. If a diamond anvil sample holder or microscope attachment is available, excellent spectra of pure samples of milligram size or even of single crystals are easily obtained. When HMX is observed in RDX-based explosives, its concentration may suggest the national origin of the explosive. 

The upper hemisphere of the steel shell is surrounded by a shielding made of reinforced concrete with a wall thickness of about 2 m. This shielding protects the nuclear part of the plant against any external impact (e. g. gas explosion, military aircraft crash) it also significantly reduces the likelihood that radionuclides will escape to the environment. The interspace between the steel shell and the secondary containment is held at sub-atmospheric pressure, so that any radionuclides penetrating the steel shell via leaks in the event of a loss-of-coolant accident would be transported by the annulus air extraction system to the standby filters and retained here, thus preventing release to the environment. 

Standard hazard analysis apply to nuclear weapon systems however, because of the political and military consequences of an unauthorized or accidental nuclear or high-explosive detonation, additional analyses are necessary to demonstrate positive control of nuclear weapons in all probable environments. The following analyses, in whole or in part, are performed ... 

---