DEMO would show that fusion can generate net electrical power and mark the final step before the construction of a commercial fusion power plant. DEMO is the machine that would explore continuous or near-continuous (steady-state) operation, tritium fuel self-sufficiency, and the large-scale production of energy and its conversion to electricity.
Countries are exploring different routes:
China has made significant progress in planning for a device called China Fusion Engineering Test Reactor (CFETR) that would bridge the gaps between ITER and DEMO. Construction of the CFETR could start at around 2020 and be followed by construction of a DEMO in the 2030s.
The European Union and Japan are jointly building a powerful tokamak called JT-60SA in Naka, Japan, as a complement to ITER on a privileged partnership called the Broader Approach. In addition to constructing the JT-60SA, the joint program consists of two other projects, the Engineering Validation and Engineering Design Activities for the International Fusion Materials Irradiation Facility (IFMIF/EVEDA), and the International Fusion Energy Research Centre (IFERC). This partnership represents a well-integrated approach to support ITER and to prepare to undertake the engineering design and construction of a subsequent DEMO.
India has announced plans to begin building a device called SST-2 to develop components for a DEMO around 2027, and then start construction of a DEMO in 2037.
South Korea initiated a conceptual design study for a K-DEMO in 2012 targeting the construction by 2037 with potential for electricity generation starting in 2050. In its first phase (2037-2050), K-DEMO will develop and test components and then utilize these components in the second phase after 2050 to demonstrate net electricity generation.
Russia plans the development of a fusion-fission hybrid facility called DEMO fusion neutron source (FNS), a reactor that would harvest the fusion-produced neutrons to turn uranium into nuclear fuel and destroy radioactive waste. The DEMO-FNS is planned to be built by 2023, and is part of Russia's fast-track strategy to a fusion power plant by 2050.
The United States is considering an intermediate step called Fusion Nuclear Science Facility (FNSF) to be used for the development and testing of fusion materials and components for a DEMO-type reactor. Plans call for operation to start after 2030, and construction of a DEMO after 2050.
The IAEA is providing a platform for information sharing and exchange in order to facilitate nuclear fusion research and the development of technology. This is a role the IAEA has continuously played over the years—acting as a central hub for collaboration among countries working first on the INTOR project, then ITER, and now DEMO.