EU project to use low-enriched uranium fissile materials as nuclear fuel

A new European Union research project, EU-CONVERSION, has been launched to accelerate using high-performance nuclear fuels, such as low-enriched uranium fissile materials. The project hopes to find ways to use such fuel sources and convert existing nuclear reactors around Europe.

The project builds on three other projects: EU-QUALIFY, LEU-FOREvER, and HERACLES-CP. It focuses on converting Germany’s FRM-II research reactor and the proposed French material test reactor Jules Horowitz (JHR).

The former, Germany’s FRM-II, relies on fuel enriched to over 95% uranium-235 to generate its dense neutron flux. Such fuel, however, is widely seen as a potential nuclear proliferation risk and is, therefore, tightly controlled.

To this end, the Technical University of Munich (TUM) has reached an agreement with the German government and the Bavarian State to work towards finding ways to use lower enrichments when suitable fuel is available.

Low-enriched uranium the future?

At present, both the Bavarian State and German governments finance the FRM-II reactor, so their buy-in is essential for the project’s success. Such an arrangement is also one of the conditions of the reactor’s operating license, first issued in 2003.

The EU-CONVERSION project has a budget of 12.8 million Euros ($13.3 million), partly funded by the European Union’s Horizon 2020 research and innovation program. Apart from TUM, several other research institutions will also partake in the project.

These include but are not limited to Framatome (France), Institut Laue-Langevin (France), Belgium’s Nuclear Research Centre (SCK-CEN), CEA (France), Université Grenoble Alpes (France), Centrum Vyzkumu Rez (Czech Republic), Statni Ustav Radiacni Ochrany (Czech Republic), and Technicatome (France).

Two candidates for low-enriched fissile fuels are being considered for the project. These are based on uranium-molybdenum (U-Mo) and another on uranium silicide (U2Si3).

Belgium’s Nuclear Research Centre’s BR2 research reactor will initially test both fuels for extreme irradiation conditions. To this end, both materials will spend between two- and three cycles (55 and 75 days) within the BR2 reactor.

According to World Nuclear News (WNN), the demonstration test will begin this year, with irradiation in 2027–2028. Test analyses, after irradiation, will continue well into the early 2030s.

Safer nuclear for Europe

“Previous irradiation testing of the candidate materials was limited to a heat flux of 470 Watts/cm2,” said Jared Wight, program manager at SCK-CEN. “This allowed us to test them in normal, operational conditions,” he said.

“In this EU project, we go a step further and increase the heat flux to more than 500 Watts/cm2. We will exceed the normal operational limits to evaluate how the fissile materials behave under extreme conditions required by FRM-II and JHR. This is crucial to ensure the safety and reliability of the reactors,” he added.

 “The nuclear industry is making efforts around the world to reduce the use of highly-enriched uranium as fissile material, which is intended to prevent a potential spread and proliferation of this material,” he added.

“The bulk of reactors have already been converted. Now it’s time for the last few – including these two reactors (FRM-II and JHR). It’s a tough challenge, however, because of their specific technical specifications. But it’s a challenge we intend to overcome in part with the help of our BR2 research reactor,” he said.

“Research strength and openness to technology without ideological blinkers are prerequisites for a good and safe future,” explained Bavaria’s Science Minister Markus Blume. “We want to operate Germany’s most powerful research reactor with innovative low-enriched fuel in the future – with the same scientific performance as before,” he added.