Producing radioisotopes in power reactors

Abstract

The demand of radioisotopes is rising due to wide-ranging applications in industry, agriculture, medicine and in research. Two sources of artificial radioisotopes are accelerators and reactors. The reactor offers large volume for irradiation, simultaneous irradiation of different samples and economy of production, whereas accelerators are generally used to produce those isotopes which can not be produced by reactor. Radioisotope production started on a significant scale in several countries with the commissioning of research reactors starting from the late 1950s. The period from 1950 to 1970 saw construction of a large number of research reactors with multiple facilities. After 1980, because of the decommissioning of many old ones, the number of operating reactors has been steadily decreasing. The research reactors used for radioisotope production could be broadly classified into swimming pool type and tank type reactors. CANDU power reactors currently produce many millions of curies per year of ⁶⁰Co for MDS Nordion’s use in industry and commerce. Studies related to production of other isotopes in power reactors have also been performed. Indeed, while a very few reactors have come online in the past decade, many more have been retired or may retire in coming years. After failure of MAPLE project, there has been unwillingness to built new reactors. Activism and politics has made it so difficult to build new reactors that we are left to use only the reactors we inherited from a nuclear era. Many design considerations and requirements for the production of isotopes in power reactors must be assessed, such as; operator and public safety, minimum impact on station efficiency and reactor operations, shielding requirements during reactor operation with target adjusters and removal of the target adjusters from core, transportation within the station, and finally the processing and shipment off-site. Use of power reactors for isotope production is reviewed.