Determination of the residual uranium content in simulant leached hulls

A measurement system has been developed to determine delayed neutrons from residual uranium in hulls interrogated with 14 MeV neutron generated by Cockcroft-Walton accelerator. Measurement principle and experimental methods were described. Dependence of the delayed neutron counts on time, 235U contents of nuclear fuels, the axial distribution of nuclear fuels, and the yields of the interrogation neutron source was determined respectively. Static and dynamic effects of the water on the delayed neutron counts were measured as well. Measurement results were presented and discussed.