Abstract
Cobalt-60 is an artificial radioisotope with a wide range of applications in many industries for its high intensity gamma-rays and longer half-life. It may be produced in research reactors from the stable isotope cobalt-59 by neutron activation when a fission neutron is absorbed in the Co-59 nucleus. The ETRR-2 research reactor is designed with an in-core neutron flux trap that accommodates space for placement of an irradiation box, which makes it suitable for the production of radioisotopes as an in-core fixed facility. This simulation study compares the production yield of Co-60 for different Co-59 pencil configurations within the irradiation box inside the in-core neutron flux trap. IAEA reference for Co-60 specifications was used to set the comparison criteria for generating different configurations. Reactor geometry and calculations were carried out using OpenMC Monte Carlo code to obtain the effective multiplication factor K
, the flux distribution, and the production yield of Co-60 with respect to time. Results show that the ETTR-2 is capable of producing Co-60 with a specific activity of 83.89 Ci g
in 263 ± 14 days following the placement of eight Co-59 pencils with 0.77 cm diameter, 32 cm in height, and 74.506 g each. It was also shown that a higher production rate may be achieved by decreasing the diameter of the pencils and increasing their number while Co-59 mass is kept constant.