Analysis of the Cobalt-60 Production in the AP1000-Like Pressurized Water Reactor Using SERPENT2

In recent years, the demand for the radioactive isotope of Cobalt-60 has grown, mostly because of its extensive applications in sterilization of medical equipment and treatment of tumors. Its production for now is mostly carried out in CANDU or RMBK reactors. However, this work analyzed the pressurized water reactor based on the Westinghouse AP1000 design, as PWRs are now considered a possible new Co-60 supplier. Specifically, three different fuel assemblies were investigated, with varying types and number of neutron burnable absorbers used and five fuel enrichments. The Co-59 was inserted as a rod with thin aluminum coating into 4, 6 or 8 guide tubes in the assembly. All calculations were performed using the SERPENT2 Monte Carlo Neutron Transport code with fuel depletion capability. The results have shown that the increased number of cobalt rods indeed led to a greater amount of Co-60 produced, however, did not affect an average per rod but reduced available reactivity. A dependence on the fuel enrichment of the mass of Co-60 produced was observed, while neutron absorbers, on the other hand, did not significantly change the production rate, which implies that the rods could possibly be inserted into various types of assemblies.