Analysis of the EU-DEMO fuel cycle elements: Intrinsic impact of technology choices

Abstract In the context of the EU-DEMO pre-conceptual design phase and the setup of a fuel cycle simulation tool, we analysed twelve prime technology candidates of the fusion fuel cycle to determine the impact of these choices and future R&D priorities. The main function and working principle of these technologies are shortly characterized and two evaluation parameters are introduced: the Technology Readiness Level and the DEMO Importance Level. The former is an approach adapted from literature to evaluate the maturity of a technology in the categories theory, experiments and integration. The latter grades the performance, reliability and impact on system robustness of each technology deriving its criticality. Ultimately, both parameters are combined to form a matrix of research priorities. Technologies of high importance and low maturity, namely the breeding blanket, metal foil pump and thermal cycling absorption process are ranked highest priority. Second priority is given to technologies of lesser criticality and maturity, such as vacuum pumps. Technologies of high maturity and importance are graded third priority. They require proper integration on a system level to counteract the boundary conditions they impose. Last priority is given to well established, reliable technologies such as cryotraps and depleted uranium getter beds.