Preliminary Inventory Data Requirements for the Safety Assessment Basis of Small Modular Reactor Used Fuel Waste for Disposal in a Canadian Deep Geological Repository

Abstract

The Nuclear Waste Management Organization (NWMO) is responsible for the safe long-term containment and isolation of used nuclear fuel in Canada. This will be accomplished through placing the used fuel in a deep geological repository (DGR).

The vast majority of used fuel destined for placement in a DGR in Canada is used CANDU fuel; however, several Small Modular Reactor (SMR) projects are progressing based on a variety of non- CANDU technologies, including liquid metal cooled, gas cooled, molten salt cooled or light water cooled with a variety of different fuel types.

Used nuclear fuel contains different radionuclides arising from fission, neutron activation and decay processes. The used fuel also contains many chemical elements as a result of these processes in addition to chemical reactions undergone during the lifetime of the fuel under irradiation, possible processing and storage. This paper presents preliminary inventory data requirements that would be needed by NWMO to determine an assessment basis for the disposal of new fuel wastes. These data do not represent the complete formal waste acceptance basis and do not guarantee acceptance. These data will contribute to NWMO’s confidence in performing adequate safety assessments, the results of which can identify potential early issues for SMR proponents to address.