A Proof of Principle Nuclear Forensics Technique for Determining 235U Enrichment from UF6 Steel Cylinders

Abstract

Non-proliferation of nuclear materials is subject to regulations and the inspection tools available to safeguard inspectors for ensuring adherence to international treaties, specifically the Non- Proliferation Treaty. This work investigated a proof of principle nuclear forensics technique to determine whether fingerprints of ²³⁵U can be detected on 48Y steel cylinder sections that previously contained natural UF₆. Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-Ray Photoelectron Spectroscopy (XPS), ToF-SIMS, Transmission Electron Microscopy (TEM) and FlashDSC were performed to determine if the surface deposition left chemical and/or radiation damage signatures that could infer the presence of high enrichment ²³⁵U via the decay products present. Additionally, compositional and calorimetric analyses were performed to identify if radiation damage was detectable in the outer layer of the oxide and was differentiable from chemical-based damage. This work concluded that some signatures of ²³⁵U were detected on 48Y cylinders and the technique has some promise for future research as an inspection tool.