Localization and Quantification of Nuclear Material in Hot Laboratories: A Geometric Solution for NMC&A

This paper introduces a package of algorithms designed to address the challenge of Nuclear Material Control and Accounting (NMC&A), which is crucial in preventing the diversion of Special Nuclear Materials (SNMs) from peaceful applications. These algorithms approximate the 3-dimensional position of radioactive material and simultaneously quantify the mass of SNM. The algorithm's efficacy was evaluated through Monte Carlo N-Particle® (MCNP®) simulations, employing a glovebox surrounded by six He-3 neutron detectors. Algorithm calibration involved simulating a point source at different positions within the experimental chamber and correlating count rates with radial distance from each detector. After evaluating test data, the average error in SNM position and mass were found to be roughly 11 cm and 3 g respectively. These results demonstrate the algorithm's potential to improve safeguard measures in laboratories with heightened background radiation levels.