Uncertainties in Biokinetic Parameters and Dose Coefficients Determined by Expert Judgement

The European Commission (EC) and the United States Nuclear Regulatory Commission (USNRC) are conducting a joint project to assess uncertainties in the results of assessment codes designed to predict the consequences of accidents at nuclear installations. The study has addressed separately each of the areas of uncertainty in the programmes: atmospheric dispersion of radionuclides; deposition and external doses; food chain transfer; internal dosimetry; early acute health effects; and late health effects. In each case, panels of experts provided estimates of uncertainties for selected parameters and documentation to support their judgement. Questions for the internal dosimetry panel concentrated on biokinetic parameters, considering the distribution and retention of radionuclides after intakes by either inhalation or ingestion. Processing of the results is in progress as part of the overall assessment of uncertainties in accident cosequence code predictions. As intended, the data obtained will provide a valuable resource for the assessment of uncertainties in doses from intakes of radionuclides for other applications.