be usable for either HEU- or LEU-based production with little or no modifications.1

Brownfield Conversion

The major advantage of Brownfield conversion is its potential cost effectiveness: It is substantially less costly to replace process equipment in an existing facility2 than to construct a new facility. However, if not properly managed and scheduled, conversion of an existing processing facility could interrupt ongoing Mo-99 production activities and result in unnecessary cost, time, and personnel radiation exposures.

The best current example of a successful Brownfield conversion is the Mo-99 processing facility in Argentina. As discussed in Chapter 7, the facility operator, Comisión Nacional de Energía Atómica (CNEA), was able to convert to LEU-based production in the same set of hot cells that were being used for HEU-based production. Moreover, this conversion was made without interrupting Mo-99 production. This conversion was possible for two reasons: First, conversion did not require substantial changes to existing target dissolution and Mo-99 recovery processes; consequently, substantial equipment modifications were not required. Second, CNEA produces Mo-99 only once a week, and so there was sufficient hot cell down time to perform the necessary process development and conversion work.

Conversion within a single set of hot cells might be more difficult when substantial process changes are required: major equipment modifications or replacements might be needed, and cross-contamination of processing lines could occur. Such conversion would also be more difficult when production is carried out more than once a week.3 Regulatory requirements may also be a barrier to conversion within the same set of hot cells. As noted in Sidebar 8.1, the Food and Drug Administration (FDA) supplemental New Drug Application approval process requires three full-scale production runs of Mo-99 on the equipment that will be used for commercial production. The process equipment must be set up for those runs but cannot be used for commercial production until FDA approval is obtained. Such approval could take several months.

1

For example, the rigs used to irradiate targets in the reactor might need to be modified if the LEU targets have a different geometry than the HEU targets they are replacing, but changes to the reactor facility itself would likely not be required.

2

This statement assumes that major facility modifications are not required. It could be costly to make major modifications to an existing facility to accommodate new process equipment.

3

Mo-99 could be shut down to allow for conversion if Mo-99 could be purchased from other sources until regulatory approvals were received to restart production with the new process.



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