It has not been reported if the reactor will use LEU or HEU targets. It is most likely that only LEU will be used. However, one feasibility study indicates that HEU can be used as well. For its operations, the reactor uses HEU fuel, supplied by Russia.
Maria reactor to produce molybdenum
Maria research reactor at the Atomic Energy Institute in Sverk, Poland will produce molybdenum-99 under an agreement with Covidien medical supply company (described in different sources as Irish or St.-Louis based). The reactor is expected to begin production in about 30 days - it is currently expecting regulatory approvals. Irradiated targets will be transported to the Netherlands for reprocessing.