Assessment of potential ORNL contributions to supply of molybdenum-99

The most widely used, and probably the most important, single radioisotope in commerce is 99Mo. Although the present supply is adequate, there are many vulnerabilities in the supply picture. Resources available at ORNL could be applied to help ensure the continued availability of this critically needed radioisotope. This assessment considers the ways in which ORNL might participate in DOE efforts to develop and maintain a domestic source of 99Mo for medical needs. The primary recommendation presented here is that ORNL obtain DOE support for development of an improved method for providing 99Mo to the user community. Specifically, development and demonstration of a system based on irradiation of enriched stable 98Mo, as opposed to fission of 235U, is recommended. Such a system would (1) alleviate the need for using highly enriched uranium as target material (nonproliferation and criticality safety concerns); (2) alleviate the need to produce a large volume of unwanted fission product wastes (safety and cost concerns); (3) promote the need for enriched 98Mo, which can be produced in the ORNL calutrons or plasma separation equipment; and (4) promote the need for a high-flux reactor, such as the High Flux Isotope Reactor (HFIR)