| Popis: |
99mTc, as the daughter of 99Mo, is the most important medical radioisotope in nuclear medicine. 99Mo is usually extracted from fission products of uranium235. Due to the restriction of treaty on the NonProliferation of Nuclear Weapons (NPT) for high enriched uranium (HEU, higher than 90% 235U enrichment that is usually 93%), it will be the trend to use low enriched uranium (LEU, less than 20% 235U enrichment that is usually 19.75%) targets for medical 99Mo production. Up to date, South Africa, Australia, Belgium and Netherland had completed the conversion from HEU to LEU technology. In this paper, based on medical application and market demand of 99Mo, opportunity and challenge of 99Mo production with LEU targets were analyzed. Non-fission 99Mo can be produced at a large scale by neutron irradiating 98Mo target in reactor, while the fabrication technology for 99Mo-99mTc generator with low specific activity of 99Mo has not been broken through, which indicates little possibility of replacement of fission 99Mo by non-fission 99Mo. For the LEU technology itself, emphasis should be put on fabrication of LEU target, high efficiency of 99Mo seperation from LEU target. |
