Simulations of Measurement of Fresh Fuel with an Organic Glass Scintillator

The U.S. Department of Energy’s Office of Nonproliferation and Arms Control sponsored different groups to design and simulate an instrument to measure fresh low enriched uranium fuel assemblies. A group from Idaho National Laboratory (INL) and Sandia National Laboratory (SNL) focused on the development and testing of current generation organic glass scintillators, and simulation of a system utilizing these detectors as a direct replacement for the liquid scintillators utilized in the International Atomic Energy Agency (IAEA) Fast-Neutron Uranium Collar (FNCL). Expected system performance was determined using MCNP simulations of fresh fuel with a range of geometries, compositions and burnable poisons. This paper will describe the development and testing of the organic scintillators for this application, as well as the validation and performance of the system based on simulations.