A comparison of environmental radionuclide concentrations calculated by a mathematical model with measured concentrations

The Pacific Northwest Laboratory (PNL) conducts an extensive environmental monitoring program at the Hanford Site to determine radioactivity in the environment attributable to Hanford operations and to determine the resulting dose to the population. Monitoring involves the collection and analysis of environmental media including air particulates, water, soil, food crops, wildlife and vegetation. Because the environmental concentrations are so low and in most cases indistinguishable from previously deposited fallout radionuclides, the population doses are calculated using computer dose codes. The model used to calculate accumulated radiation doses from chronic ingestion of food products is incorporated in the PABLM computer code. This code estimates the transfer of radionuclides from air and irrigation water to plants and calculates the resulting concentration of radionuclides in food products. In this study, the concentrations of 90Sr as calculated by PABLM were compared with measured concentrations obtained through the environmental monitoring program to determine how well the computer code predicts the environmental concentrations