Year
2013
Abstract
Under the Additional Protocol, state signatories must report all nuclear-fuel-cycle-related activities and material inventories in their respective countries, including source material that is not suitable for fuel fabrication but exceeds 10 metric tons of uranium and/or 20 metric tons of thorium. This includes thorium in by-products like mining tails and sludge from non-nuclear activities. This work describes the development of a cost-effective methodology of determining thorium content in mining tailings for countries with limited analytical laboratory resources. Gamma-ray spectroscopy is currently one of the most efficient techniques used to determine low concentrations of radioactive materials in samples. Spectroscopy techniques combined with advanced computational capabilities for efficiency calibration modeling provide an effective solution to this issue. This paper describes the quantification of thorium content in tin mining tailings in Indonesia using a high-purity germanium detector and In-Situ Object Counting System (ISOCS) software. Measurements were conducted on four different sample types acquired from tin mines in Indonesia: high-grade monazite, low-grade monazite, dry ilmenite, and wet ilmenite. The samples were measured during an advanced nondestructive assay (NDA) workshop on the quantification of nuclear material with Badan Pengawas Tenaga Nuklir (BAPETEN) of Indonesia. Measurement results are presented with a comparison to destructive assay findings that provide validity to the proposed solution.