National Research Council (NRC) empanelled a Committee1 to assist the Department in developing a long-range science plan for the management of radioactive high-level waste (HLW) at Department of Energy (DOE) sites. Currently, the Environmental Management National Research Council (NRC) empanelled a Committee1 to assist the Department in developing a long-range science plan for the management of radioactive high-level waste (HLW) at Department of Energy (DOE) sites. Currently, the Environmental Management Science Program (EMSP) provides DOE's Office of Environmental Management (EM) “with basic research addressing fundamental issues that may be critical to advancing technologies under development, but not yet implemented.” The NRC provides you with this interim report to help the EMSP develop a request for proposals (RFP) aimed towards HLW management that will be published in the Federal Register by the end of this year. This report has been reviewed in accordance with the procedures of the NRC and reflects a consensus of the Committee.>>>>>>In addition to the Committee's expertise in relevant technical disciplines and knowledge of DOE problems, several other sources of information were used to develop this interim report. The Committee reviewed a previous NRC report on the EMSP, as well as three other NRC reports relevant to high-level waste management at DOE sites. The Committee also held three information-gathering meetings to familiarize itself with the problems at four major HLW sites.>>>