Abstract: As the first sodium coolant fast reactor in China, CEFR has the characteristics such as high power rating, high neutron flux and high neutron leakage as its hard spectrum. These leakage neutrons can be used to produce radioisotope ⁶⁰Co in reflecting layer region by means of some special optimization designs, including introducing moderator, choosing appropriately geometrical structure design, reasonable irradiation location and irradiation cycle length, to improve specific activity of ⁶⁰Co. The codes MCNP and ORIGEN2 were used to perform the calculations. The higher specific activity of ⁶⁰Co can be obtained by these optimization designs, so it is feasible to produce ⁶⁰Co utilizing these leakage neutrons in reflecting layer region of CEFR.