Postclosure Safety Assessment: Gas Modelling

Ontario Power Generation (OPG) is proposing to build a Deep Geologic Repository (DGR) for Low and Intermediate Level Waste (L&ILW) near the existing Western Waste Management Facility at the Bruce nuclear site in the Municipality of Kincardine, Ontario. The Nuclear Waste Management Organization, on behalf of OPG, is preparing the Environmental Impact Statement (EIS) and Preliminary Safety Report (PSR) for the proposed repository.
The project involves investigation of the site’s geological and surface environmental characteristics, conceptual design of the DGR, and safety assessment. The postclosure safety assessment (SA) evaluates the long-term safety of the proposed facility and provides supporting information for the EIS and PSR.
This report describes numeric modelling work undertaken to calculate the generation and build-up of gas in the repository, the exchange of gas and groundwater between the repository and the surrounding rock, and between the rock and the surface environment. The results are used to inform the postclosure safety assessment modelling of potential dose impacts of the repository gases.