GOLDSIM models of long-term radiation impact of conditionally cleared radioactive material

Management of waste materials from the decommissioning of nuclear installations offers opportunities for optimization. Large amounts of waste materials with low contents of various radionuclides could be recycled to save financial resources or repository capacity. The increase of the share of recycled materials compared to the current practice could be accomplished by applying the conditional clearance concept. Conditional clearance, as up to now is an unproven theoretical concept, demands utilization of the cleared material for the previously defined purpose (e.g., building construction). Safety studies needed for realization of this practice have to prove that conditionally cleared material will not cause radiation impact exceeding levels prescribed in health and safety regulations. Safety studies assess radiation impact during all manipulations with low level radioactive material (e.g., melting, component manufacturing, building of construction, etc.) as well as its impact on inhabitants living near the construction built using conditionally cleared material. The article is focused on modeling and calculation of long-term radiation impact on inhabitants living near the constructions. Models (scenarios) of various building applications were simulated using GOLDSIM software with Radionuclide Transport Module. Scenarios were selected according to information from the civil engineering business to cover the types of buildings most suitable for application of conditionally cleared material. The results of the calculations showed that conditional clearance represents no significant safety issue in the long-term. Calculated individual effective doses received by inhabitants did not exceed the given dose constraint (10μSv/year) in case of any scenario evaluated. Detailed and transparent studies of the long-term impact of conditionally cleared materials are important especially for winning of public acceptance. •Long-term radiation impact of conditionally cleared material was investigated.•Conditionally cleared material was reused in building constructions.•6 models of reuse of conditionally cleared material were implemented in GoldSim.•Output parameters of calculations were individual effective doses of public.•Conditional clearance presents no significant health risk in the long-term.