Non-destructive assay of nuclear materials using a self-indication method

Abstract

The integrity test applicable to TRU fuel containing MA with high radioactivity and high decay heat is important for safety. Neutron resonance transmission analysis is adapted for identification and quantification of nuclides in fuels by neutron time-of-flight measurement. In this work, a self-indication method was applied to the measurement of the transmitted neutron. The validation of the self-indication method was performed by using a pulsed neutron source and natural uranium samples at the KURRI-LINAC. The results show that the target areal density can be easily determined from the reduction of the counting rate around the resonances with and without sample. It was confirmed that the reduction ratio due to the neutron resonance absorption can be estimated to within 10%. The numerical estimation showed that the areal density of fuel material can be determined in the range from 10⁻⁶ to 10⁻² (b⁻¹) using multiple resonances and suitable thickness self-indicator.