Technical feasibility assessment of RUTA-70 nuclear pool-type reactor as a heat-only energy source for district heating systems in Finland

Abstract

Climate change challenges make governments shift to practical measures in order to mitigate the irreparable consequences of climate change. In June 2019, the Finnish Government introduced its programme, where one of the targets was to achieve nearly emission-free energy generation by the end of the 2030s. In terms of district heating, Small Modular Reactors can be employed as an emissionfree heat source. The studied district heating nuclear plant concept RUTA represents high safety features and reliable technical solutions that are supported by sufficient operational experience. Moderate temperature of the cermet fuel cladding and atmospheric pressure in the reactor vessel make the probability of a design basis accident extremely low. The reactor core utilises mostly constructive and technical solutions of the VVER technology that has already proven its reliability and accumulated rich operation experience. However, some novel and innovating solutions as well as siting close to densely populated areas create legal and regulative obstacles to the realisation of the RUTA concept in Finland. Due to reliable safety features and referent reactor core solutions, RUTA-70 can be evaluated as a strong candidate to replace fossil and biomass-fuelled power plants, but changes to the nuclear energy legislation and regulations are necessary.