PSI and NUKEM Sign Memorandum of Understanding to Advance TRISO Fuel and HTR Technologies

The cooperation centers on the development and application of TRISO fuel, a high-performance nuclear fuel for which NUKEM brings decades of experience in design and production, as well as on Small Modular Reactor (SMR) concept based on High-Temperature Reactor (HTR) technology currently under conceptual development at PSI. A key objective of the collaboration is the integration of TRISO fuel into PSI’s reactor design while considering the entire fuel cycle, including spent fuel recycling, conditioning and ultimate disposal. From the earliest design stages, safety, sustainability, and back-end aspects will be incorporated to ensure a technically sound and industrially viable solution.

Under the MoU, the partners will collaborate in several core areas, including

• Reactor concept studies, modeling and simulation, and the development of safety and licensing frameworks;
• TRISO fuel development, qualification, and evaluation of pathways toward scalable industrial production;
• Systematic integration of life-cycle considerations into the design process to ensure long-term sustainability and regulatory compliance.

The collaboration builds on the complementary strengths of both partners. PSI contributes its scientific expertise and leadership in reactor physics, safety analysis, and research infrastructure, while NUKEM provides engineering know-how and experience in translating advanced nuclear concepts into practical and implementable solutions.

 “The second Memorandum of Understanding signed with PSI marks an important milestone in our cooperation. It brings together NUKEM’s long-standing experience in TRISO fuel design and production, rooted in its historical track record in Hanau, Germany, with PSI’s scientific and safety-oriented expertise in HTR and SMR technologies. This collaboration enables an integrated approach to the nuclear fuel life cycle from an early design stage, providing a solid and realistic basis for the development of industrially viable SMR and HTR concepts. Building on activities in Switzerland, Germany, and Japan, we also envisage future deployment in the Arab region and Central Asia,” says Nobuaki Ninomiya, Executive Officer and Managing Director of NUKEM.

Andreas Pautz, head of the Center for Nuclear Engineering and Sciences at PSI adds: “By joining forces, PSI and NUKEM are laying the technical groundwork to accelerate the development of a Generation IV High Temperature Reactor design. PSI is one of the few places in the world with the necessary experimental infrastructure and expertise to investigate the behavior of advanced nuclear reactor fuels, such as NUKEM’s TRISO, under irradiation conditions. By deploying an ultra-safe nuclear fuel design and, in parallel, developing a reactor concept for industrial high-temperature applications such as process heat and hydrogen generation, NUKEM and PSI are building on their past successes as well as European and Japanese leadership in driving this promising technology forward.”

The shared goal is to develop a fuel and reactor concept that remains technically robust, licensable, and industrially realistic throughout the development process.”

This MoU builds upon the agreement previously signed by the two parties on 27 August 2025 and further defines the scope and depth of the planned research and development collaboration.

NUKEM Technologies Engineering Services GmbH in Karlstein am Main, Germany, is world-wide active in the areas of management of radioactive waste and spent fuel, decommissioning of nuclear facilities, engineering and consulting. For more than 65 years NUKEM provides high quality products, technologies and services, where Innovation, Solutions and Excellence are closely linked.

PSI is the largest research institute for natural and engineering sciences in Switzerland, conducting cutting-edge research in four main fields: future technologies, energy and climate, health innovation and fundamentals of nature. PSI develops, builds and operates complex large research facilities and is also Switzerland’s center of excellence in nuclear energy research. It operates unique nuclear infrastructures, e.g. the PSI Hot Laboratory, a well-equipped facility for work and research on radioactive material. The know-how of PSI is instrumental for the safe operation of the Swiss nuclear reactor fleet, the disposal of radioactive waste in the deep geological repository, and the training and education of the next generation of nuclear scientists and engineers.