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

Abstract

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 decontainment 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.

Coprecipitation of actinide peroxide salts in the U–Th and U–Pu systems and their thermal decomposition

“…The mixture was spread onto a Si low background sample holder, and covered by a hermetic fully removable sample dome, compatible with a Bruker D8 goniometer installed in a glovebox. 52…”

“…For Pu containing samples, the powder is mixed with 30 mg of silicone grease for particle immobilization. The mixture is spread onto a Si low background sample holder, covered by an hermetic fully removable sample dome, compatible with Bruker D8 goniometer installed in a glovebox [52].…”

“…The mixture was spread onto a Si low background sample holder, and covered by a hermetic fully removable sample dome, compatible with a Bruker D8 goniometer installed in a glovebox. 52 For mixed oxide samples, the powder is dispersed in 180 mg of glue diluted with 60 µL of acetone. The mixture is spread onto a metallic plate and left to dry overnight.…”

Multi-scale structural investigation of uranium-plutonium mixed oxides (U1-yPuy)O2-x with high plutonium content

“…The mixture was then dispersed in a polymer grease in order to avoid spreading powder. Further details can be found in Vauchy et al [VAU21]. The diffraction patterns were collected by scanning from 20° to 140° 2θ with a set-interval of 0.1° 2θ and a counting time of 5 seconds per step.…”

Simple preparation of specimens for X-ray powder diffraction analysis of radioactive materials: an illustrative example on irradiated granite

“…Different approaches have been used to fulfill those requirements. In some laboratories, the whole diffractometer is inside a glove box, where the sample preparation and measurement are carried out under nitrogen atmosphere (Belin et al, 2015), others developed a sample stage dedicated for irradiated samples (Vauchy et al, 2021). Inspired by holders for air-sensitive samples (Ritter, 1988;Rink et al, 1994;Rodriguez et al, 2008), other authors designed a holder to enclose the sample avoiding the powder exchange with the external atmosphere.…”