Toward a modification of the soil compartment of the CSA N288.1 environmental transfer model for permafrost conditions

The Canadian road map for Small Modular Reactors (SMRs) details that possible uses for SMRs includes providing electricity to remote communities. Many of the communities in the Canadian Arctic use diesel fuel generators to provide electricity. SMRs provide a possible future alternative to the combustion of fossil fuels in these communities. This has been done before by the United States Army Nuclear Power Program (ANPP) and Russia currently uses two SMRs to supply electricity in the Arctic. For power reactors in Canada, Derived Release Limits must be calculated using the N288.1 environmental compartment model. There is a compartment for soil in the N288.1 model that includes a few different soil types. However, the compartment is not suitable for soils that are underlain by permafrost (cryosols). In this paper we describe how the N288.1 soil compartment could be modified for permafrost conditions, and specifically those representative of the continuous permafrost zone, where 90–100 % of the ground underlying the surface is perennially frozen. We provide example calculations using the modified version of the N288.1 soil compartment representative of conditions around Inuvik, a site in continuous permafrost. In general the specific calculations of the modified N288.1 standard tend to decrease the value of the P₁₃ (air to soil) transfer factor.