Fast neutron coincidence counter using scintillators for safeguards verification of the TRU/RE waste

To minimize the environmental burden of the disposal of spent nuclear fuel, nuclide management process is one of good candidates to separate and collect major nuclides in the spent nuclear fuel. After high heat load nuclides, high mobile nuclides, and long-lived nuclides are separated, collected, and fabricated as the waste form for the disposal. From safeguards perspective, nuclear material of the TRU/RE waste form should be verified. The amount of Plutonium can be estimated by Cm/Pu ratio using burnup code calculations and Cm-244 measurement. In this study, a fast neutron coincidence counter for Cm-244 neutron measurement of the TRU/RE waste form was designed with EJ-276 plastic scintillation detectors using PTRAC of MCNP6.2. The preliminary experimental performance evaluation using one EJ-276 plastic scintillation detector was conducted. And total and coincidence counting efficiency using a Cf-252 neutron source was calculated with respect to the number of detectors.