Comparison of Two Radiological Exposure Models for Landfilled Waste Containing Tritium: A Case Study. M. L. Socolof, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6190
To dispose of hazardous sludge that contains a small amount of radioactive material in a commercial facility, the U.S. Department of Energy (DOE) requires the preparation of a radiological dose assessment. DOE has proposed to dispose of hazardous sludge at the Laidlaw Environmental Services of South Carolina, Inc. treatment, storage, and disposal facility in Pinewood, South Carolina. This sludge contains radioactive tritium in concentrations of 28.3±1.4 pCi/g. The objective of this study is to compare two conceptual exposure models to assess the possible radiological impact to landfill workers at the Laidlaw facility due to the buried waste. Inhalation exposure is calculated using the following two conceptual models: (1) one-dimensional diffusion through the landfilled waste, and (2) evapotranspiration and leaching through the landfilled waste using the RESRAD computer code, Version 5.60. The results reveal similar doses using the two different models. The diffusion model results in a slightly higher dose; however, the difference between the doses is within the margin of error of the initial tritium concentration sampled in the sludge. Implications of this study show that the use of either model has the same precision for this type of exposure calculation. The advantages and disadvantages of each model are also presented.
Work supported by Lockheed Martin Specialty Components Company under the U.S. Department of Energy Contract DE-AC05-96OR22464.