A screening model for depleted uranium testing using environmental radiation monitoring data

Information from an ecological risk assessment of depleted uranium test areas at Yuma Proving Ground (YPG) was used to update the required environmental radiation monitoring (ERM) plan. Data to be collected for the ERM can also be used to evaluate the potential for adverse radiological and toxicological effects to terrestrial reptiles and mammals in the affected areas. We developed a spreadsheet-based screening model that incorporates the ERM data and associated uncertainties. The purpose of the model is to provide a conservative estimate of radiological exposure of terrestrial, biota to DU using the ERM data. The uncertainty in the estimate is also predicted so that the variation in the radiological exposure can be used in assessing potential adverse effects from DU testing. Toxicological effects are evaluated as well as radiological effects in the same program using the same data. Our presentation shows an example data set, model calculations, and the report of expected radiation dose rates and probable kidney burdens of select mammals and reptiles. The model can also be used in an inverse mode to calculate the soil concentration required to give either a radiological dose that would produce a potential adverse effect such as fatal cancer or a toxicological dose that would result in nephrotoxic effects in mammals