Minimizing Public Radiation Dose at Decommissioned Mine Sites for Future Land Use Opportunities

Abstract

Waste disposal and decommissioning strategies can be employed to reduce public radiation dose at former mine sites that have become contaminated with naturally occurring radioactive material (NORM). A former mine site in Ontario, licensed by the Canadian Nuclear Safety Commission (CNSC) plans to accept NORM waste from another former mine site under the condition that the additional waste material does not increase the environmental or public health and safety risk associated with the existing site. A gamma survey was conducted to characterize existing radiation dose on the site to site inspectors, casual users and potential future residents. Various disposal options for waste from another former mine site were evaluated based on minimizing dose to future users. Radioactive soil sorting based on gamma levels and varying soil cover depths were explored as shielding mechanisms. Shielding calculations were performed using MicroShield to inform the disposal and decommissioning strategy.