(e.g., AECL in Canada; CERCA in France), which manufacture and store the HEU and targets until they are needed by the isotope producers. The targets can be shipped to the reactors in less-than-formula quantities.5

  1. The security requirements for all nuclear facilities, including the research and test reactors that are used to irradiate targets for medical isotope production, were raised in many countries, including the United States, following the September 11, 2001, terrorist attacks on the United States. Consequently, the costs of security have increased even for facilities that use only LEU for medical isotope production or other purposes. However, these costs are still lower than those for facilities that store greater than formula quantities of HEU.


The second issue of concern to producers is the regulatory requirements for drug quality and purity. Some producers have questioned whether Mo-99 made from LEU targets will have the same quality and consistency as that made from HEU targets. Experience to date with LEU-based production indicates that Mo-99 purity and consistency should not be an impediment to conversion. ANSTO produced Mo-99 for medical isotope use with 1.8–2.2 percent LEU targets until 2007, when it shut down its HEU-fueled reactor (High Flux Australian Reactor) and prepared to start up its LEU-fueled replacement reactor (Open Pool Australian Lightwater reactor) and produce Mo-99 using 19.75 percent LEU targets. ANSTO reported to the committee that the Mo-99 produced from the 1.8–2.2 percent LEU targets, and Mo-99 produced from test batches of 19.75 percent LEU targets, had lower impurities than HEU-based Mo-99 and met British Pharmacopeia limits for impurities.6 ANSTO was carrying out low-activity Mo-99 production trials as the present report was being finalized for release. A representative of ANSTO reported that the quality of Mo-99 from these runs was high and equivalent to the quality of HEU-based Mo-99 it was receiving from large-scale commercial suppliers.7 CNEA has been producing Mo-99 using 19.75 percent LEU targets since 2002. A representative of that organization told the committee that Mo-99 purity has been consistently higher than that produced using HEU targets. Purity data for CNEA-produced Mo-99 is presented by Durán (2005).


The costs of transporting larger quantities of HEU from storage to target producers would likely be significantly higher than the costs of transporting LEU. However, such transport occurs relatively infrequently compared to transport of targets.


There is no U.S. Pharmacopeia (USP) for Mo-99 because it is not used for diagnostic imaging procedures. However, there is a USP for Tc-99m.


Ian Turner, ANSTO, written communication with study director Kevin Crowley, December 10, 2008.

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