For purposes of the discussion in this report, thermal technologies are organized into two subgroups: open and contained. In open technologies, emissions are not contained or treated before release into the environment. In contained technologies, emissions are contained and treated before release into the environment. A particular subgroup of contained thermal technologies, explosive destruction technologies (EDTs), will also be discussed.
If an open technology were used, the emissions from separated rocket motor disposal would need to be within the allowed limits provided in the Air Pathway Assessment section of the Resource Conservation and Recovery Act (RCRA) Subpart X permit for the facility using the technology. In the case of a contained technology, gases and particulate material would be captured and treated with the unit's pollution abatement equipment. The contained technologies would need to be permitted through RCRA Subpart X and would have to meet release limits agreed on with the Kentucky Department for Environmental Protection.
Open detonation involves placing whole or broken-down rocket motors in a pile with a booster explosive. Detonation of the pile initiates a chemical reaction that converts organic energetic materials to carbon dioxide, nitrogen, and water. Emissions from the process do not undergo further treatment and are released into the local environment. They can include metals in the energetic material (such as lead in the M28 rocket propellant), traces of unreacted energetics, materials in the rocket motor cases released and ejected by the detonation, and entrained soil from the detonation site. Noise issues and weather often limit the conditions under which these detonation events can be conducted.
Open detonation has several advantages. Handling of energetic items is minimized, and this reduces the risk of unexpected initiation and harm to personnel or facilities. Secondary waste streams are limited to unreacted materials, mostly metal components from the detonated solid rocket motors, such as the case and the fins. Data in emissions databases are sufficient to allow an estimation of total emissions from the process (Erickson et al., 2005; EPA, 2009). Efforts are under way to improve the databases (Kim, 2010; Wright et al., 2010).
This technology also has many disadvantages. Emissions are not further treated before release into the environment. In particular, there is a potential for releases of respirable particles from metal components of the energetic formulation, such as the lead in the rocket propellant, or from the soil. Noise issues often cause concerns for facility neighbors and result in regulatory limitations on when the treatment can occur. Propellants like that in the motors of M55 rockets can be difficult to detonate completely, and incomplete detonation occasionally results in distribution of unreacted energetics