Source-term development for a contaminant plume for use by multimedia riskassessment models

Multimedia modelers from the US Environmental Protection Agency (EPA) and U S Department of Energy (DOE) are collaborating to conduct a comprehensive a nd quantitative benchmarking analysis of four intermedia models: MEPAS, MMS OILS, PRESTO, and RESRAD. These models represent typical analytically based tools that are used in human-risk and endangerment assessments at installa tions containing radioactive and hazardous contaminants, The objective is t o demonstrate an approach for developing an adequate source term by simplif ying an existing, real-world, Sr-90 plume at DOE's Hanford installation in Richland, WA, for use in a multimedia benchmarking exercise between MEPAS, MMSOILS, PRESTO, and RESRAD.:Source characteristics and a release mechanism are developed and described; also described is a typical process and proce dure that an analyst would follow in developing a source term for using thi s class of analytical tool in a preliminary assessment. (C) 2000 Elsevier S cience B.V; All rights reserved.