Sonochemical decontamination of magnesium and magnesium-zirconium alloys in mild conditions

JOURNAL OF HAZARDOUS MATERIALS

卷:406

Article

Ji, Ran¹  Virot, Matthieu¹  Pflieger, Rachel¹  Nikitenko, Sergey I.¹ 

[1] Univ Montpellier, CNRS, CEA, ICSM,UMR 5257,ENSCM, Marcoule, France

关键词: Decontamination;    Uranium;    Ultrasound;    Cavitation;    Structuring;   

DOI  :  10.1016/j.jhazmat.2020.124734

来源: Elsevier

【 摘 要 】

UNGG cladding nuclear wastes constitute a huge volume of Mg-based materials that raises economic and safety concerns, particularly due to their radioactivity coupled to the potential generation of H-2 gas under deep underground disposal. Their significant decontamination would result in more secure and less expensive storage, with a better containment of the separated long-lived radioisotopes that could enter in a classical channel. Sonication of genuine UNGG cladding materials and simulants at 345 kHz in 0.01 M oxalic acid solution (20 degrees C) allowed the structuring of their surfaces with the observation of homogeneously distributed craters of 20-40 mu m in diameter. After a thorough characterization and comparison of the ultrasound effects generated at the surface, the various samples were artificially contaminated and characterized before sonication. The complete and rapid sonochemical decontamination of Mg-based materials was then observed, in addition to the removal of the carbon layer promoting corrosion on the inner UNGG cladding. The extension of sonication allows the neo-formed brucite (Mg(OH)(2)) and zirconium-based phases to accumulate on the surface, thus contributing in a slight but continuous surface recontamination process. This phenomenon results from the re-adsorption of uranyl cations from the solution which can be avoided by optimizing the duration of treatment.

【 授权许可】

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