Study of the volatilization of Cesium and Rhenium in the waste vitrification process - Archive ouverte HAL Access content directly
Journal Articles Journal of Nuclear Materials Year : 2022

Study of the volatilization of Cesium and Rhenium in the waste vitrification process

(1, 2) , (1) , (1) , (1) , (2)
1
2

Abstract

A side effect of high level waste vitrification at 1100°C is the volatilization of radioactive cesium (Cs), recaptured further on in the process as a solid aerosol by a dust scrubber. Feedback from industry suggests that Cs combines with technetium (Tc) █ simulated here by rhenium (Re), chosen for its similar behavior █ to form volatile species. This work characterized Cs volatilization and aerosol formation. The first experiment involved elaborating and analyzing a simplified glass enriched with Cs and Re, which reinforce the volatilization phenomena. The results showed that a demixed liquid phase rich in Cs, Re, Mo, and Na formed in the liquid melt, which is reminiscent of a molybdic phase evoked in the literature. Moreover, analyzing the condensed gases led to the conclusion that the alkalis and Re volatilize congruently at around 700°C. In the second experiment, a series of measurements of the gas phase characterized aerosols throughout the process. The size distribution results showed that the particles formed in the furnace were mostly submicronic, and that the aerosols in the calciner and the dust scrubber included nanoparticles and micronic particles. SEM-EDS characterization revealed the composition of a spherical particle from the furnace made of two nested phases: one rich in Cs-Re-O, and the other rich in Na-Mo-O. The analyses performed showed that Cs and Re could be found in every particle sampled throughout the process, and that the micronic particles might originate from the aggregation of submicronic particles because of composition similarities. Thus, the observations led to a better understanding of the behavior of the elements of interest in both the melt and the gas phase.
Fichier principal
Vignette du fichier
Preprint - T. Charpin bis v6.pdf (2.09 Mo) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

cea-03442399 , version 1 (23-11-2021)

Licence

Attribution - NonCommercial - NoDerivatives - CC BY 4.0

Identifiers

Cite

Thomas Charpin, Alain Ledoux, Caroline Michel, Sophie Schuller, Dominique Thomas. Study of the volatilization of Cesium and Rhenium in the waste vitrification process. Journal of Nuclear Materials, 2022, 558, pp.153381. ⟨10.1016/j.jnucmat.2021.153381⟩. ⟨cea-03442399⟩
88 View
50 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More