3. Increasing difficulty of transporting Mo-99 across international borders, especially by air.

Supply reliability is in comparatively better shape in other major world regions, notwithstanding the recent outages that are discussed elsewhere in this chapter. As noted in Chapter 3 and discussed in more detail elsewhere in this chapter, Europe is in the process of replacing two aging reactors; Australia recently commissioned a new reactor (Open Pool Australian Lightwater [OPAL]) and plans to bring a new Mo-99 production facility online in 2009; and Argentina recently upgraded its Mo-99 production facilities and has also begun planning to replace its aging reactor (RA-3).

The discussion in this chapter is organized into three sections. The first provides an examination of general Mo-99 supply reliability issues independent of whether HEU or LEU targets are used to produce this isotope. The second section provides an examination of Mo-99 supply reliability issues that could arise as a result of conversion from HEU to LEU targets. The third and final section provides findings to address the study charge.

The general supply reliability issues that will be discussed in this section arise roughly on two timescales: days to weeks (short timescales) and months to years (long timescales). Over short timescales, supply reliability problems are primarily the result of:

1. Planned or unplanned facility outages combined with limited excess capacity for Mo-99 production elsewhere.

2. Problems with transporting Mo-99 from production facilities to technetium generator producers.

Such disruptions, although temporary, can lead to severe disruptions in diagnostic imaging procedures that can affect the continuity of patient care.

All of the reactors that produce Mo-99 must be shut down periodically for refueling and other maintenance. Even the best run and maintained reactors will be shut down on a monthly or more frequent basis for a total of at least 50 days per year (see Table 3.2). The operational programs and planned shutdowns of reactors in Europe (Belgian Reactor II [BR2], High Flux Reactor [HFR], and Osiris) and South Africa (Safari-1) are coordinated so that there is available reactor capacity for medical isotope production.³ Also, the two European Mo-99 producers (Mallinckrodt and