Questioning nuclear scale-up propositions: Availability and economic prospects of light water, small modular and advanced reactor technologies

This paper addresses the pressing need for rapid decarbonization of energy systems by examining the role of nuclear power in future energy scenarios collected in the IPCC database. Despite their explorative character, energy scenarios can influence decision-makers or might be used to promote certain technology developments. They are increasingly subject to the integration into real-world settings and thus the need for feasibility assessments has emerged in literature. The case of nuclear power is of particular interest, for which proponents project steep capacity increases, whereas literature shows a technology in decline. The paper investigates this discrepancy and questions the nuclear scale-up in energy scenarios by investigating proposed technology scaleup thresholds for low carbon scenarios. By doing so, it moves beyond the often-applied aggregate view of nuclear power and explores the techno-economic feasibility from a reactor-technology-specific lens. Three reactor technologies are chosen: currently dominant high-capacity light water reactors, small modular reactors, and nonlight water-cooled reactors (so-called "new" or "advanced" reactor concepts). Results indicate that none of the currently proposed reactor technologies are fit for necessary rapid decarbonization due to availability constraints and economic challenges. We further suggest the adaptation of proposed thresholds to absolute metrics based on energy generation and towards the inclusion of a sub-technology specific perspective. Overall, the need for further scrutiny of energy scenarios, particularly concerning nuclear power, is emphasized in order to prevent instrumentalization by political and industry actors.