A great wave has been emerging in nuclear research and development in the world, as shown by the many proposals, conceptual designs, plans and constructions of advanced reactors such as innovative light water reactors and small modular reactors. In this wave, there have been important research and development in the field of nuclear fuel including advanced technology fuel, high-assay low enriched uranium required by many advanced reactor concepts, high-performance cladding, high-fidelity simulation, application of artificial intelligence, deployment of additive manufacturing, and elucidation of irradiation effects driven by nanoscale observation technologies. It is a great honor for us to host the international conference TopFuel 2026 in Japan which brings together experts from all over the world to discuss these fascinating research and development in the field of nuclear fuel. We hope that fruitful discussions among our colleagues lead to successful development of nuclear fuel technology.

It is a great pleasure for us to host a traditional international conference on nuclear fuels, TopFuel, in 2026, with the cooperation of the Korea Nuclear Society and China Nuclear Society. As TopFuel 2026 executive committee, we would like to state the following three points. The first point is the name of the conference. This series of conferences were called WRFPM when these were held in East Asia. But, from now on, we would like to call TopFuel, in line with the names in Europe and North America. The second is the choice of venue. To facilitate the participation of experts in this important international conference from all over the world, we chose Shinagawa, one of Tokyo's major terminals, considering its easy access from both Japan's major international airports, Haneda and Narita. The third is the scope of the meeting. Following the successful TopFuel 2025 held in North America, advanced fuels such as the fuels for fast reactors, gas-cooled reactors and molten salt reactors were added to the scope of the conference, expecting that the increase in the fuel types addressed in the conference creates synergies in research and development of nuclear fuels. We hope that our colleagues from around the world will enjoy the TopFuel 2026 International Conference in Shinagawa, Tokyo.