Environmental Chemistry of Radionuclides : Open Questions and Perspectives

Abstract

Since the discovery of nuclear fission, atomic energy has become for mankind a source of energy, but it has also become a source of consternation. This Perspective presents and discusses the methodological evolution of the work performed in the radiochemistry laboratory that is part of the Institut de Chimie de Nice (France). Most studies in radioecology and environmental radiochemistry have intended to assess the impact and inventory of very low levels of radionuclides in specific environmental compartments. But chemical mechanisms at the molecular level remain a mystery because it is technically impossible (due to large dilution factors) to assess speciation in those systems. Ultra‐trace levels of contamination and heterogeneity often preclude the use of spectroscopic techniques and the determination of direct speciation data, thus forming the bottleneck of speciation studies. The work performed in the Nice radiochemistry laboratory underlines this effort to input speciation data (using spectroscopic techniques like X ray Absorption Spectroscopy) in environmental and radioecological metrics.

Atomic spectrometry update: review of advances in elemental speciation

“…Speciation analyses, mostly by X-ray spectrometries, form the bulk of a discussion (55 references) of the work performed in the radiochemistry laboratory at the “Institut de Chimie de Nice” (France) regarding the environmental chemistry of radionuclides that started in response to the nuclear fallout from the Chernobyl incident. 20 The authors rejected the term “heavy metal” preferring to refer to the analytes as “trace radionuclides” or “metallic trace radionuclides” pointing out that for environmental studies the elements in question come from every part of the periodic table, including noble gases. They argued that because very large dilution factors occur in the environment, chemical toxicity might be considered negligible in comparison with long-term radiation effects (radiotoxicity) and that speciation information is essential for understanding the biochemical pathways at the origins of possible chemical and radiological toxicities.…”

Thermodynamics of the Eu(iii)–Mg–SO4–H2O and Eu(iii)–Na–SO4–H2O systems. Part I: solubility experiments and the full dissociation Pitzer model

“…[2][3][4] Besides sharing the same valency, these trivalent lanthanides and actinides have similar structural properties (ionic radii and f-orbital electrons) leading to comparable chemical behavior, including the formation of aqueous complexes of similar stability. [5][6][7][8] The emplacement of nuclear waste in underground repositories is one of the options favored by the international community for the disposal of nuclear waste. In the event of water intrusion, aqueous systems involving radionuclides may form.…”

“…2–4 Besides sharing the same valency, these trivalent lanthanides and actinides have similar structural properties (ionic radii and f-orbital electrons) leading to comparable chemical behavior, including the formation of aqueous complexes of similar stability. 5–8…”