Masahiko Tani
Session Speaker
Masahiko Tani, Ph.D., is a Professor at the University of Fukui's Research Center for Development of Far-Infrared Region, a Senior Science and Technology Policy Fellow at Japan's Cabinet Office, and a Visiting Professor at Osaka University. He earned his Ph.D. in Atomic and Molecular Physics and Spectroscopy from Kyoto University in 1992. His career includes roles as Director of the Dramatic Weather Science Research Center (2026–present), Director of the Far-Infrared Region Research Center (2014–2023), and Associate Professor at Osaka University (2000–2008). His research focuses on terahertz spectroscopy, imaging, photoconductive antennas, nonlinear optics, and ultrafast spectroscopy. He chairs Japan's Terahertz Technology Forum and has made pioneering contributions to THz science, publishing extensively in leading journals.
Tritium Supply and Demand Challenges, and Strategies for Securing Startup Inventories for D-T Fusion Reactors
Securing the initial tritium inventory is a critical challenge for the deployment of deuterium-tritium (D-T) fusion reactors. Canada is reported to hold approximately 80% or more of the world's tritium for non-military use, with its current inventory estimated at 30–35 kg. Meanwhile, the initial tritium inventory required for a medium-sized tokamak reactor is estimated to be approximately 20 kg. Although ITER's D-T operation is scheduled for 2039, fusion startups, including CFS, plan to begin D-T operation of magnetic confinement fusion demonstration devices around 2027. If full-scale D-T experiments by these companies and other organizations begin in the late 2020s, tritium available for such experiments could rapidly be depleted unless production increases dramatically, leading to a supply crisis, or a tritium supply “cliff.”
This presentation first examines the supply and demand for initial tritium inventories quantitatively. It then addresses the anticipated supply cliff by comparing technologies for efficient tritium production, assessing approaches such as D-D startup to reduce initial tritium requirements, and discussing regulatory requirements for handling kilogram-scale quantities of tritium. On this basis, strategies for tritium procurement and production are proposed to support the deployment of fusion reactors.
(1) Scenarios for potential supply-demand gaps from the 2030s onward and associated price increases are presented, taking into account the retirement schedules of CANDU reactors, which produce tritium as a by-product, available tritium inventories, and fusion reactor deployment plans.
(2) Technologies for efficient tritium production are compared in terms of efficiency, cost, and technology readiness level (TRL). The options considered include light-water reactors, heavy-water reactors (including CANDU reactors), co-production in high-temperature gas-cooled reactors (HTGRs), and accelerator-driven systems (ADS).
(3) Startup based on deuterium-deuterium (D-D) reactions is examined as a means of reducing the initial tritium inventory. The requirements for implementing this approach are assessed, considering factors such as cost and the time required for startup.
Drawing on these analyses, tritium procurement and production strategies are proposed for Japan and like-minded countries, taking into account regulatory requirements and economic security considerations.