PNNL

Abstract

An On-site Inspection (OSI) is an important component of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) with the objective of gathering evidence of a possible Treaty violation. This includes the use of gamma-spectrometry equipment to identify 17 particulate radionuclides that are fission or activation products and indicative of a nuclear explosive test. This research provides an evaluation of high-, medium- and low-resolution detectors using modelled radionuclide signatures from a nuclear explosion and Monte Carlo simulations of a detector response. Simulations have been performed for a broad energy germanium (BEGe), cadmium zinc telluride (CZT), lanthanum bromide (LaBr3(Ce)) and sodium iodide (NaI(Tl)) detector. The complex radionuclide signatures are shown to only be distinguishable using a high-resolution system for both 1 week and 1 year post-detonation cases.