is now increasing in use in the United States. In radiography, the inconvenience of imposing radiation protection procedures at job sites and the inherent limitations of radiography have driven practitioners to shift to other techniques for nondestructive inspection, such as phased-array ultrasound. In well logging, there are barriers to switching away from americium-beryllium sources, but the difficulties, costs, and exposures associated with these sources give the industry cause to look for better practices. It is clear to the committee that the large contract irradiator companies do not yet see strong incentives to shift from gamma irradiation to x-ray irradiation, and so this may be another area where additional encouragement is needed. Again, however, the committee’s discussion focuses on radioactive cesium chloride.
Finally, mention of a policy option in this chapter does not constitute an endorsement of that option. Indeed, some are mentioned to highlight their undesirable qualities and consequences.
Table 10-1 summarizes four classes of generic policies: prohibitions, push incentives, pull incentives, and supply incentives. For each of these classes, several possible generic policies and their major advantages and disadvantages are shown.
Prohibitions are the most direct way to eliminate radionuclide use. They force either replacement or abandonment of use. Rescinding already-issued licenses would be extremely costly in some cases, in light of investments made by users in anticipation of the continuation of the licenses, and would require compelling arguments to support the action. Even when narrowly applied, prohibitions are very blunt in removing both uses for which replacements are readily available as well as those for which particular circumstances make replacement infeasible or extremely costly. Because of these disadvantages, rescinding already-issued licenses is likely to be neither feasible nor desirable. Some observers may argue that if the U.S. NRC determines that a set of radiation sources pose substantial risks, then it should impose a swift, categorical prohibition. Few situations, however, offer clearly unacceptable risks.2
Prohibitions on new licenses (i.e., no sales or import of sources) offer more promise. Although they leave the existing stocks of radionuclide sources in place, they effectively cap the total number so that over time there will be a decline as the sources decay and units are retired. The determination of which uses to no longer license requires confidence in the existence of commercially viable replacement technologies. Even if replacements are commercially viable in general, there may be specific applications for which replacement is commercially infeasible. Therefore, prohibitions on new licenses would have to be carefully targeted to avoid losing benefits of radionuclide use that cannot actually be replaced with current technology.
Push incentives seek to make replacement technologies relatively more attractive to potential adopters by internalizing more of the external costs (TRC + OSC) of use of radionuclides, as discussed in Chapters 1 and 3.
One way to accomplish this is to impose more stringent requirements on users. The most desirable requirements would reduce the risks associated with use. For example, additional requirements to ensure physical security or the quick discovery of diversions would both reduce the risks and increase the costs of radionuclide use. The increased costs would make replacement technologies relatively more attractive. Developing effective regulations,
The selective banning of the type of sources involved in the Decatur, Georgia incident is one example. The banning of a certain design of connectors for attaching radiography source “pigtails” to drive cables is another. The latter action was taken following an accident in California in 1979 in which a plant worker received a serious radiation burn when he picked up a radiography source that had detached from the drive cable unnoticed by the radiographer (U.S. NRC, 1982).