The European Union has embarked on an ambitious project, EU-CONVERSION, aimed at revolutionizing the fuel used in high-performance research reactors. This initiative seeks to explore low-enriched uranium (LEU) as a viable alternative to the current high-enriched uranium (HEU) used in reactors like Germany's FRM-II and the upcoming French Jules Horowitz Reactor (JHR), which is expected to become operational in the 2030s. EU-CONVERSION is the latest in a series of projects, following EU-QUALIFY, LEU-FOREvER, and HERACLES-CP, all dedicated to enhancing nuclear fuel safety and efficiency.

Currently, the FRM-II reactor operates with uranium enriched to over 95% uranium-235, a level that poses significant nuclear proliferation risks. The Technical University of Munich (TUM), in collaboration with the German government and the Bavarian State, has pledged to transition to lower enrichment fuels as soon as a suitable alternative is developed. This transition is a condition of the reactor's operating license, which was issued in 2003.

With a substantial budget of EUR12.8 million (USD13.3 million) from the EU's Horizon 2020 research and innovation program, EU-CONVERSION brings together a consortium of leading institutions. These include the Technical University of Munich, Framatome, Institut Laue-Langevin, Belgium's Nuclear Research Centre (SCK-CEN), CEA, Université Grenoble Alpes, Centrum Vyzkumu Rez, Statni Ustav Radiacni Ochrany, and Technicatome.

The project is evaluating two promising fissile materials: uranium-molybdenum (U-Mo) and uranium silicide (U2Si3). These materials will undergo rigorous testing at the BR2 research reactor at SCK-CEN, where they will be exposed to extreme irradiation conditions over two to three cycles, each lasting between 55 and 75 days. Preparations for these tests are set to begin this year, with irradiation planned for 2027-2028, followed by detailed post-irradiation analyses through 2030.

Testing Under Extreme Conditions

Jared Wight, program manager at SCK-CEN, highlighted the project's innovative approach: "Previous tests of these materials were conducted at a heat flux of 470 Watts/cm², simulating normal operational conditions. In this project, we are pushing the limits by increasing the heat flux to over 500 Watts/cm². This will allow us to evaluate the materials' performance under the extreme conditions required by FRM-II and JHR, ensuring both safety and reliability."

Wight added, "The global nuclear industry is committed to reducing the use of highly-enriched uranium to mitigate proliferation risks. While most reactors have already transitioned, FRM-II and JHR present unique challenges due to their specific technical requirements. However, with the capabilities of our BR2 research reactor, we are confident in overcoming these challenges."

Commitment to Innovation and Safety

Markus Blume, Bavaria's Science Minister, underscored the importance of this initiative: "Our commitment to research excellence and technological openness is crucial for a secure future. We aim to operate Germany's most powerful research reactor with innovative low-enriched fuel, ensuring it retains its scientific capabilities."

This project not only represents a significant step forward in nuclear safety and non-proliferation but also highlights the EU's dedication to fostering innovation in the nuclear sector. By developing and implementing safer, more efficient reactor fuels, EU-CONVERSION is poised to set new standards for research reactors worldwide.