Methodology to compare alternative design options for radioactive waste disposal facilities under the principle of ALARA based on probabilistic approach with Bayesian inference

Abstract

In the process of optimisation of radiological protection in long-term radioactive waste management, design options for disposal facilities are assessed from the viewpoint of practical reduction in radiation dose to as low as reasonably achievable (ALARA). In this paper, a probabilistic approach is introduced to evaluate differences in dose distributions between alternative facility designs using the Bayesian inference technique. It is demonstrated by a series of parametric calculations for hypothetic disposal system designs that an additional dose from an disposal facility could be sufficiently reduced from the viewpoint of dose reduction under the ALARA principle if the design option for a disposal facility whose 95th percentile of dose distribution is lower than the target dose of 0.1 mSv/y is provided. Reducing uncertainties of the distribution of dose from disposal options is also an important aspect for the practical reduction in radiation dose to which members of the public are exposed.