Safety assessments relating to the use of new fuels in research reactors: application to the case of FRM 2 reactor fuel

After giving a brief reminder of the procedure applied in France for the licensing of the use of a new fuel type or design in a research reactor, we outline the main safety aspects associated with such a modification. Finally, by way of an example, we focus on the safety assessment relating to the IRIS irradiation device used in SILOE reactor, in particular for the qualification of the fuel dedicated to FRM II reactor of the Technical University of Munich. This qualification was carried out on a U3Si2 fuel plate enriched to about 90 % in weight of 235U and containing 1.5 g of uranium per cm3. The evaluation performed by the IPSN for GRS did not call into question the choice of U3Si2 fuel plates for the FRM-II reactor. (authors)