The committee developed the following findings based on its assessment of the first and last charges in its study task: With respect to the first charge to assess “the feasibility of procuring supplies of medical isotopes from commercial sources that do not use HEU,” the committee finds that:

  • LEU targets that could be used for large-scale production of Mo-99 have been developed and demonstrated.

  • These targets could be used in reactors and processing facilities that produce large-scale quantities of medical isotopes for the U.S. market. However, producers might have to make modifications to their facilities or process equipment to use these targets (see Chapter 7) and the targets must be compatible with existing reactors.

  • At present, there are not sufficient quantities of medical isotopes available from LEU targets to meet U.S. domestic needs. However, the committee sees no technical reasons that adequate quantities cannot be produced from LEU targets.

  • The anticipated total cost increase from production of medical isotopes without the use of HEU would be less than 10 percent for at least three of the four30 current large-scale producers (Mallinckrodt, IRE, and MDS Nordion31). This is true for costs at three points in the Mo-99/Tc-99m supply chain: Mo-99 production, technetium generators, or Tc-99m doses. In fact, a 10 percent cost increase for Mo-99 would provide very substantial resources for conversion and would have a negligible impact on the cost of common diagnostic imaging procedures.

The committee recommends that producers and the U.S. government consider several steps to improve the feasibility of conversion. The steps discussed in this chapter include the following:

  • Mo-99 producers. Commit to conversion, announce a best-effort schedule for selecting and implementing an LEU-based Mo-99 production process, and identify additional needs for technical assistance. Work with industry organizations and scientific and medical societies concerned


The South African producer, NTP Radioisotopes, declined to participate in this study. This organization uses South African HEU for Mo-99 production. It is in the process of converting its reactor to LEU fuel but to the committee’s knowledge has not announced a schedule for converting to LEU targets.


The finding that MDS Nordion could convert for less than a 10 percent cost increase assumes that AECL intends to continue production of Mo-99 over the long term as discussed elsewhere in this chapter.

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