Small Nuclear Reactor—Nordic District Heating Case Study

Small Modular Reactors (SMRs) have been recognized to have potential in decarbonizing district heating, which is currently an urgent sustainability challenge in many European countries. In this paper, the financial impacts of replacing peat and biomass-powered Combined Heat and Power (CHP) plants with heat-only reactors of 24–200 MW power range and maximum output temperatures of 120 °C are studied. A district heating system of a medium-sized Nordic city in Eastern Finland is modeled with EnergyPRO computer software (EMD International A/S, Aalborg, Denmark), which is used to optimize plant units’ production for cost effectiveness. A future scenario is used to predict electricity prices, expenditures from CO2 emission allowances, and fuel prices for the studied case. Results show that the low operating expenditures of CO2 free heat-only reactors would compensate for the revenue losses from electricity sales and that a small number of micro reactors, with power output in the tens of megawatts range each, would be optimal for the studied case. Since investment cost estimates for SMRs still bear significant uncertainties, the subject should be followed in further studies, as heat-only SMRs could provide a profitable alternative for current CHP production in the future.