Probabilistic Assessment of Dose to Workers due to Radiological Emergency Situation

Korea Institute of Nuclear Safety performs dose assessment to the workers in the event of an unexpected radiation accident by field investigation, interviews with workers, colleagues and reproducible experiments. In most cases, the circumstances of an accident are reconstructed based on a statement of the worker. Parameters necessary for dose assessment include stay time near the radiation source, distance from the source and surrounding structure, etc. When these variables are applied at a single value, the results are not considered for such uncertainties and are overestimated or underestimated. In this study, we derived possible accident scenario by reconstructing from the actual accident case in industrial radiography field, and performed evaluating dose for the scenario by applying probabilistic approach. In the actual accident case, the variables for calculating dose such as time, distance, shielding are not sure and it has high uncertainty. Hence, a probabilistic approach for estimating dose is meaningful in that valuable information can be obtained to provide appropriate radiation safety protection and management, such as assessing exposure dose and taking measures in an accident scenario.