Nuclear power as a climate mitigation strategy - technology and proliferation risk

Recent years have witnessed renewed interest in nuclear power in large extent due to the need to reduce carbon emissions to mitigate climate change. Most studies of cost and feasibility of stringent climate targets that include nuclear power focus on the currently available light water reactor (LWR) technology. Since climate mitigation requires a long-term commitment, the inclusion of other nuclear technologies such as mixed oxide-fuelled LWRs and fast breeder reactors may better describe the future energy supply options. These different options also entail different nuclear weapon proliferation risks stemming from uranium enrichment or reprocessing of spent fuel. To investigate this relation, we perform a scenario analysis using the global energy transition model. Our results indicate that meeting a scenario with a 430 ppm CO2 target for 2100 is feasible without the involvement of nuclear power; however the mitigation costs increase by around 20%. Furthermore, a lasting contribution by nuclear power to climate change mitigation can only be achieved by alternative fissile material production methods and global diffusion of nuclear technologies. This in turn bears important implications for the risk of nuclear proliferation for several reasons. First, knowledge and competence in nuclear technology becomes more accessible, leading to the risk of nuclear programmes emerging in states with weaker institutional capacity. Additionally, even if the reprocessing step in a fast breeder cycle proves to be essentially proliferation resistant, the build-up of breeder reactor systems necessitates a long transition period with large-scale use of enrichment technology and its related proliferation risks. Our study does not include the costs posed on society by nuclear accident risk and by the need to upscale safeguards and regulatory capacity to deal with increased proliferation risk.