T he Idaho National Engineering Laboratory published Phase II results of an Integrated Thermal Treatment System Study commissioned by the U.S. Department of Energy's http://www.em.doe.gov/fs/fs1d.html> Office of Science and Technology. To date, the study consists of systematic engineering evaluations of 19 thermal treatment alternatives for contact-handled, mixed low-level waste currently stored by DOE. The waste consists of organic and inorganic solids and liquids contaminated with radioactive substances. Treatment systems that will destroy the organic material in the waste are needed. Other operations are needed to stabilize the treatment residues, inorganic materials, and radionuclides prior to disposal.
Incineration is a mature technology that has been the primary choice of industry for destroying hazardous wastes because the technical risks are low and the costs are well established. In Phase I of the study, which was published in March 1995, ten thermal treatment systems based on incineration and plasma destruction were evaluated. The systems were:
In spite of years of successful experience with incineration, the public is opposed to it. As a result, research organizations, industry, and DOE have developed or proposed alternative thermal treatment concepts. Nine innovative alternatives to incineration were evaluated in Phase II of the study. The nine alternatives focused on thermally based technologies, with the exception of two systems that use chemical processes that operate at moderate temperatures. The alternative treatment systems evaluated in Phase II were:
Both phases of the study evaluated the systems' life-cycle costs, gaseous effluent quantities, energy requirements, and solid residue volumes. Reviewers paid specific attention to stack emissions and hazardous (especially radioactive) solid residue disposal required by each system because they are major concerns of the public. A third phase of the study is currently planned to review additional non-thermal processes on a similar basis.
The purpose of the study was to assess the costs and performance of various treatment systems measured against treatment of a fixed, heterogeneous DOE waste stream. The report provides comparative data and was not designed to draw specific conclusions or make recommendations. An abstract of the Phase II results is available on a publicly accessible database run by the Office of Science and Technical Information of the Oak Ridge National Laboratory. Call (423) 576-8401 or request the abstract via e-mail at reports@adonis.osti.gov. Request document DE96-000981.
