FJOH summer school is an advanced post-graduate-level course aimed at junior as well as experienced scientists and engineers engaged in the broad field of nuclear sciences, engineering and technologies.

Lecturers are invited from internationally leading universities and industry. The School format encourages informal discussions and the exchange of knowledge between lecturers and participants.

The Frédéric Joliot / Otto Hahn Summer School course represents the continuation of the Frédéric Joliot Summer Schools on “Modern Reactor Physics and the Modelling of Complex Systems”, which was created by CEA in 1995 to promote knowledge in the field of reactor physics, in a broad sense, and the international exchange of teachers, scientists, engineers and researchers. Beginning in 2004, the scope of the School was extended to include scientific issues related to nuclear fuels. The venues of the FJOH School sessions alternate between Karlsruhe and Aix-en-Provence.

The program of each School session is defined by the International FJOH Scientific Board.

FJOH is jointly organized by the IRESNE Research Institute on Nuclear Systems for Low-Carbon Energy Production (CEA Energy Division, France) and the Karlsruhe Institute of Technology (KIT, Germany).

The FJOH-2025 participants will learn about the development of reactor concepts such as HTRs, LFRs, MSRs, OCRs, HPCRs, relative to the LWRs which came to dominate the commercial nuclear power sector. The focus will be on designs for which demonstrators and power plants were actually built and operated in the early decades of the nuclear power industry. The lectures will lay emphasis on “the science behind the technologies”, namely:

• What was the approach used to make the initial design choices, what was the scientific basis, how were the main engineering trade-offs made?
• How did the concepts and designs evolve over time with the lessons learned from (i) actual reactor operation (including unexpected phenomena) and technological developments; (ii) improved understanding of basic phenomena, material physical, chemical and fluid properties, limiting factors; (iii) progress in theory, experiments, models and simulations?
• What are the anticipated design, safety, and operating challenges associated with future (AMR) versions of these reactors?
• How can our modern knowledge-based approaches and advanced Modelling & Simulation methods help us overcome these challenges and open up new frontiers for nuclear, besides the classical heat-to-electricity conversion?

By the end of the course, the participants should be able to describe the main learning steps in the development of these reactors, discuss the main gaps and challenges associated with the corresponding AMRs, and motivate the R&D which is needed to address them.

FJOH-2025 includes plenary lectures, seminars, and technical visits. The invited speakers are internationally recognized experts from leading universities, R&D laboratories, and industry.

The FJOH-2025 participants will have the opportunity to practice their freshly-acquired knowledge as part of group activities. Time for these group activities is set aside in the School schedule.

Glossary

HTR                      High Temperature Reactor

LFR                       Lead-Cooled Fast Reactor

MSR                      Molten Salt Reactor

OCR                      Organic Cooled Reactor

HPRC                    Heat-pipe Cooled Reactor

LWR                       Light-water Reactor