New sample stage for characterizing radioactive materials by X-ray powder diffraction: application on five actinide dioxides ThO₂, UO₂, NpO₂, PuO₂ and AmO₂

A new sample stage for characterizing radioactive materials by X-ray powder diffraction was developed at the ATALANTE facility (CEA Marcoule, France) using a conventional (non-nuclearized) Bruker D8 goniometer mounted in Bragg-Brentano geometry. The setup consists of a removable, fully hermetic sample stage, with a 200 μm-thick beryllium window, that can be plugged onto a glove-box, allowing the sample to be introduced in an hermetic medium that also encapsulates the glove-box atmosphere throughout the analysis process. The whole setup is thus hermetically unplugged from the glove-box and positioned on the centre of the goniometer. No preliminary decontamination and/or de-containment of the sample is necessary. The device was developed to avoid an expensive and time-consuming nuclearization of the diffractometer while also keeping it easily accessible for maintenance. Ultimately, keeping the diffractometer out of a glove-box also limits the volume of the final nuclear wastes, and thus the removable sample stage is the only 'active' part. X-ray diffraction results of two NIST standards LaB₆ and α-Al₂O₃ as well as five actinide dioxides ThO₂, UO₂, NpO₂, PuO₂ and AmO₂ are presented to show the efficiency of the setup. (authors)