What does the conversion entail?
Developing the LEU fuel
To achieve the lowest possible enrichment - the target is <20% U-235 (LEU) - the fissile uranium must be packed more densely in the fuel element so that the scientific and industrial users of the FRM II continue to have access to an excellent high neutron flux without disproportionate losses. A so-called high-density fuel required for this is not yet in use worldwide and will, therefore, first be developed and qualified for high-performance research reactors such as the FRM II.
Agreements on the conversion
An agreement between the Federal Republic of Germany and the Free State of Bavaria and an ancillary provision of the 2003 operating license for the FRM II, therefore, stipulates that the FRM II must also be converted to a fuel with a uranium-235 enrichment < 50 %, provided that a suitable fuel is available.
In addition, the obligation to convert the FRM II is also laid down in the current cooperation agreement of the Heinz Maier-Leibnitz Zentrum (MLZ) between the Technical University of Munich and the Helmholtz Centres Jülich and Hereon from December 2020.