Performance assessment methods for mixed waste sites at the Savannah River Plant

Risk assessment techniques were applied to Savannah River Plant (SRP) waste facilities as part of a program on waste site cleanup and groundwater protection. The components of risk assessment and the technical basis for application of the risk evaluation process to the principal pollutants at SRP (radionuclides, toxic chemicals, and carcinogenic compounds) are given. An extensive technical data base from the fields of radiation health physics, toxicology, and environmental sciences is required. Data are summarized for each class of contaminant and parameter values are provided for use in numerical analysis of risk. A review of risk assessment uncertainties and the limitations of predictive risk assessment are summarized. Risk estimators for each class of contaminants at the SRP were tabulated for radionuclides, toxic chemicals, and carcinogens from the technical literature. Estimation of human health risk is not an additive process for radiation effects and chemical carcinogensis since their respective dosimetric models are distinctly different - even though the induction of cancer is reported to be the common end result. Risk estimation for radionuclides and chemical carcinogens should be tabulated separately. Impacts due to toxic chemicals in the biosphere should also be estimated as a separate entity because toxic chemical risk estimators are uniquely different and do not reflect the probability of a detrimental health effect. 29 refs., 3 figs., 2 tabs