The purpose of this Environmental Impact Statement (EIS) is to provide environmental imput into the selection and implementation of final disposal actions for high-level, transuranic and tank wastes located at the Hanford Site, Richland, Washington, and into the construction, operation and decommissioning of waste alternatives. Specifically evaluated are a Hanford Waste Vitrification Plant, Transportable Grout Facility, and a Waste Receiving and Packaging Facility. Also an evaluation is presented to assist in determining whether any additional action should be taken in terms of long-term environmental protection for waste that was disposed of at Hanford prior to 1970 as low-level waste (before the transuranic waste category was established by the Atomic Energy Commission but which might fall into that category if gernerated today.).

Chemical pretreatment of nuclear wastes refers to the sequence of separations processes used to partition such wastes into a small volume of high-level waste for deep geologic disposal and a larger volume of low-level waste for disposal in a near-surface facility. Pretreatment of nuclear wastes now stored at several U. S. Department of Energy sites ranges from simple solid-liquid separations to more complex chemical steps, such as dissolution of sludges and removal of selected radionuclides, e. g. , 90Sr, 99Tc, 137CS, and TRU (transuranium) elements. The driving force for development of chemical pretreatment processes for nuclear wastes is the economic advantage of waste minimization as reflected in lower costs for near-surface disposal compared to the high cost of disposing of wastes in a deep geologic repository. This latter theme is expertly and authoritatively discussed in the introductory paper by J. and L. Bell. Seven papers in this volume describe several separations processes developed or being developed to pretreat the large volume of nuclear wastes stored at the US DOE Hanford and Savannah River sites. These papers include descriptions of the type and amount of important nuclear wastes stored at the Hanford and Savannah River sites as well as presently envisioned strategies for their treatment and final disposal. A paper by Strachan et al. discusses chemical and radiolytic mechanisms for the formation and release of potentially explosive hydrogen gas in Tank 241-SY-101 at the Hanford site.