Year
2018
Abstract
Uranium hexafluoride (UF6) destructive assay (DA) sampling and analysis is a key component in the International Atomic Energy Agency’s (IAEA’s) layered safeguards approach for uranium conversion and enrichment plants. Gram-quantity UF6 samples are collected during inspections and generally stored under tag and seal until transportation is arranged to an off-site analytical laboratory. The shipping time can be long and evolving restrictions on radioactive/corrosive material shipments may increasingly limit the IAEA’s ability to easily transport UF6 samples. The Pacific Northwest National Laboratory (PNNL), Los Alamos National Laboratory (LANL), and Argonne National Laboratory (ANL) are developing three new UF6 DA sampling technologies and methods that are intended to address these challenges, as well as provide a DA sample geometry that might be useful for on-site analysis methods currently under development. The samplers collect a much smaller UF6 sample than current practices, and then convert the UF6 into a safe, chemically-stable uranium compound that is significantly easier to handle and transport. It is likely most samples could simply be shipped in a package with only a UN2910 label and no shipping documents, as compared to the more demanding UN3507 UF6 shipping requirements. In 2017, a Phase I field exercise was conducted at PNNL to demonstrate the efficacy of PNNL’s Single-Use Destructive Assay (SUDA) sampler, LANL’s Planar Alumina-based Deposition for Destructive Analysis (PADDA) sampler, and ANL’s Handheld Operation Rapid Uranium Sampler (HORUS) in a laboratory environment that approximated an on-site DA sampling inspection. Depleted UF6 (DUF6) DA samples were collected from PNNL’s UF6 sampling tap testbed, and then surveyed, packaged, and transported to a PNNL analytical laboratory. Uranium was extracted from the DA samples using a simple protocol, and then assayed by mass spectrometry. DA samples and samplers were easily shipped back to LANL and ANL as UN2910 excepted radioactive material. In 2018, a Phase II field exercise was conducted at ORNL, where multiple low enriched UF6 materials were sampled, shipped long-distance, and then analyzed. The field exercise results provided valuable feedback for the technology developers, stakeholders, and potentially the IAEA.