Fusion Energy

Transdisciplinary Fusion Energy Center
Launched the “Fusion System Design Engineering” Program, A Series of Corporate-Sponsored Research Programs

Fusion energy*¹ is attracting attention as a next-generation energy source that utilizes nuclear fusion reactions.
The revised National Strategy of June 2025 outlines the development of a fusion industry ecosystem—involving industrialization advancement, R&D capacity enhancement, and systematic human-resources development—while “aiming to be a world leader in demonstrating power generation in the 2030s.” The Graduate School of Frontier Sciences (GSFS) established the Transdisciplinary Fusion Energy Center (TFEC) in April 2025 and launched the “Fusion System Design Engineering” corporate-sponsored research program in partnership with eight private companies in May. This feature article will introduce the latest trends and GSFS’s initiatives toward the practical application of fusion technology.

 

Fusion Energy is Gaining Momentum

Hidden Potential of Fusion Energy
Fusion reactions, which occur continuously in the core of the Sun, are nuclear processes that release immense energy; power generation based on these reactions is often referred to as creating a “Sun on Earth.”
The current research and development is focused on the deuterium (D)–tritium (T) reaction, which uses D and T as fuel. This reaction releases an amount of energy equivalent to that produced by approximately 8 tons of petroleum from just 1 gram of fuel.
Because D is abundant in seawater and T can be produced from lithium in seawater, fuel for D–T reactions is not limited by geographic origin in the way fossil fuels are. In addition, fusion reactions do not emit carbon dioxide and there is no risk of runaway chain reactions or high-level-radioactive-waste generation, which occurs in nuclear fission in nuclear power generation (although low-level radioactive waste will be generated).
If fusion energy becomes commercially viable, it could dramatically transform the global energy landscape, advancing carbon-free solutions against global warming while bolstering energy security.

Current Status and Future of Fusion Energy
Fusion research has been a long journey of repeated study and demonstration of various elemental technologies using experimental devices. Various methods for generating and controlling plasma were proposed in the past. Notably, in the 1960s, the former Soviet Union successfully conducted plasma experiments using the tokamak system, wherein excellent magnetic confinement performance was achieved and which later became the global standard.

We have now reached a stage where elemental technologies can be combined into a system capable of sustaining fusion reactions. This is exemplified by ITER*², an experimental reactor.
However, the experimental reactor only serves to demonstrate the fusion core system. A “DEMO” reactor will confirm whether electricity can be generated practically. Beyond the DEMO reactor lies a “practical” reactor that can generate electricity using fusion reactions at the commercial scale.
Fusion research still involves many unresolved questions. In recent years, numerous startups have emerged, offering compact, innovative reactor designs beyond the traditional tokamak system.

Japan as a World Leader
It is no exaggeration to say that Japan’s position in fusion research is that of a world leader. This is not only due to the accumulation of many years of research but also because the foundation of related industries is well established within the country. In parallel with the ITER project, Japan and Europe jointly developed the plasma experimental device named JT-60SA, whose construction was completed in 2020 at the Naka Institute for Fusion Science and Technology (Ibaraki Prefecture) of the National Institutes for Quantum Science and Technology (QST). The device is about half the size of ITER and is currently the largest tokamak-type device in the world. Many of its parts and equipment are domestically produced.
Leveraging this advantage, Japan aims to be the first in the world to realize a DEMO reactor in the 2030s. In addition to the Joint Special Design Team for Fusion DEMO, composed of members from across Japan, accelerating its activities, the industry–academia collaborative “FAST” project^*3, which aims to demonstrate power generation in the 2030s, was launched in 2024.

*1 The Fusion Energy Innovation Strategy implemented in 2023 states that “this strategy labels nuclear fusion energy as fusion energy.”

*2 Pronounced as “ee-ter.” The world’s largest tokamak fusion reactor, now under construction in France, is a joint effort by seven regions spanning 33 countries, including Japan, the European Union (EU), and the United States. Due to construction delays and other factors, the completion year, which was originally 2025, has been pushed to 2034.

*3 FAST (Fusion by Advanced Superconducting Tokamak) is a private-sector industry–academia collaborative project centered around Starlight Engine Ltd. This company is a subsidiary of Kyoto Fusioneering Ltd., a nuclear fusion startup of the Kyoto University, which conducts burning experiments using T in a tokamak-type experimental device.

 

Significance and Purpose of the “Fusion System Design Engineering” Corporate-Sponsored Research Program

Transdisciplinary Fusion Energy Center is Established
In April 2025, GSFS established the Transdisciplinary Fusion Energy Center, which will be responsible for everything from basic research on fusion energy to its social implementation.
This center advances research pertaining to the core technologies essential for practical implementation, while developing integrated systems through transdisciplinary collaboration with a broad range of stakeholders.
At the same time, the center aims to cultivate young researchers and industrial professionals, contributing to the early implementation and industrialization of fusion energy in society and the creation of a decarbonized society.

 

Fig  Organizational Structure of the Fusion Energy Center

 

Course Launched with the Cooperation of the University of Tokyo and Eight Private Companies
In May 2025, the University of Tokyo and eight private companies launched the “Fusion System Design Engineering” corporate-sponsored research program.
As a part of the Transdisciplinary Fusion Energy Center, this course aims to build academic foundation for designing fusion plants through industry–academia collaboration and to advance the early realization of fusion energy by developing academic and technological frameworks that support the various components of fusion plants.
This course will also cultivate fusion energy professionals and contribute to the development of the industry.