Neutron flux density profiling during iridium irradiation

Using the perturbation method, the dependence of the specific activity of 192Ir on the variation of neutron flux density is investigated. It has been shown that sensitivity of the specific activity of 192Ir value at a given irradiation time depends on the time-point of neutron flux perturbation, being greater if perturbation is introduced at the end of the irradiation cycle. Practical realisation of a proposed scheme will allow an increase in 192Ir specific activity together with savings in reactor fuel, due to the lower level of reactor power at the beginning of the cycle.