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Partitioning of the rare earths and actinides between R7T7 nuclear glass alteration products and solution according to disposal conditions; Partage des terres rares et des actinides entre solution et produits d`alteration du verre nucleaire type R7T7 en fonction des conditions de stockage

Abstract

The alteration of nuclear glass by water is liable to release radionuclides into the environment. Determining the release kinetics of these elements and their aqueous chemical forms are therefore essential steps in establishing the safety of a geological repository site. Leach tests were conducted with a nonradioactive specimen of the French ``R7T7`` light water containment glass spiked with U and Th, and with two R7T7 specimens spiked with {sup 237}Np and {sup 239}Pu, respectively. The alteration solution compositions were representative of deep groundwater and contained carbonate, sulfate, phosphate, fluorine and chlorine ions. The release of U, Th, Np and Pu, as well as of the rare earths La, Ce and Nd were monitored by ICP mass spectrometry and by {alpha} spectrometry. Scanning and transmission electron microscopic examination of the nonradioactive altered glass surfaces was also performed to assess the partitioning balance for the rare earths, U and Th between the glass alteration products and solution. The mobility of these elements depends on two competing mechanisms. The rare earths and thorium are incorporated in the alteration products (gel); the retention process is assumed to involve chemisorption or coprecipitation, enhanced in the gel layer by the presence of phosphate ions in particular.  More>>
Authors:
Publication Date:
Oct 25, 1995
Product Type:
Thesis/Dissertation
Report Number:
FRCEA-TH-518
Reference Number:
SCA: 052002; 400201; PA: AIX-27:057250; EDB-96:117991; NTS-97:000710; SN: 96001635174
Resource Relation:
Other Information: TH: These (D. es Sc.).; PBD: 25 Oct 1995
Subject:
05 NUCLEAR FUELS; 40 CHEMISTRY; BOROSILICATE GLASS; LEACHING; VITRIFICATION; RADIOACTIVE WASTE DISPOSAL; RADIOACTIVE WASTES; FRACTIONATION; CERIUM; CHEMISORPTION; CONTAINMENT; DECOMPOSITION; FISSION PRODUCTS; GEOLOGIC DEPOSITS; GROUND WATER; LANTHANUM; NEODYMIUM; NEPTUNIUM 237; PLUTONIUM 239; REPROCESSING; SOLUBILITY; THERMODYNAMIC PROPERTIES; THORIUM; TRANSMUTATION; UNDERGROUND DISPOSAL; URANIUM
OSTI ID:
265887
Research Organizations:
CEA Centre d`Etudes de la Vallee du Rhone, 30 - Marcoule (France). Dept. d`Exploitation du Retraitement et de Demantelement; Aix-Marseille-3 Univ., 13 - Marseille (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
Other: ON: DE96632329; TRN: FR9602026057250
Availability:
INIS; OSTI as DE96632329
Submitting Site:
FRN
Size:
273 p.
Announcement Date:

Citation Formats

Menard, O. Partitioning of the rare earths and actinides between R7T7 nuclear glass alteration products and solution according to disposal conditions; Partage des terres rares et des actinides entre solution et produits d`alteration du verre nucleaire type R7T7 en fonction des conditions de stockage. France: N. p., 1995. Web.
Menard, O. Partitioning of the rare earths and actinides between R7T7 nuclear glass alteration products and solution according to disposal conditions; Partage des terres rares et des actinides entre solution et produits d`alteration du verre nucleaire type R7T7 en fonction des conditions de stockage. France.
Menard, O. 1995. "Partitioning of the rare earths and actinides between R7T7 nuclear glass alteration products and solution according to disposal conditions; Partage des terres rares et des actinides entre solution et produits d`alteration du verre nucleaire type R7T7 en fonction des conditions de stockage." France.
@misc{etde_265887,
title = {Partitioning of the rare earths and actinides between R7T7 nuclear glass alteration products and solution according to disposal conditions; Partage des terres rares et des actinides entre solution et produits d`alteration du verre nucleaire type R7T7 en fonction des conditions de stockage}
author = {Menard, O}
abstractNote = {The alteration of nuclear glass by water is liable to release radionuclides into the environment. Determining the release kinetics of these elements and their aqueous chemical forms are therefore essential steps in establishing the safety of a geological repository site. Leach tests were conducted with a nonradioactive specimen of the French ``R7T7`` light water containment glass spiked with U and Th, and with two R7T7 specimens spiked with {sup 237}Np and {sup 239}Pu, respectively. The alteration solution compositions were representative of deep groundwater and contained carbonate, sulfate, phosphate, fluorine and chlorine ions. The release of U, Th, Np and Pu, as well as of the rare earths La, Ce and Nd were monitored by ICP mass spectrometry and by {alpha} spectrometry. Scanning and transmission electron microscopic examination of the nonradioactive altered glass surfaces was also performed to assess the partitioning balance for the rare earths, U and Th between the glass alteration products and solution. The mobility of these elements depends on two competing mechanisms. The rare earths and thorium are incorporated in the alteration products (gel); the retention process is assumed to involve chemisorption or coprecipitation, enhanced in the gel layer by the presence of phosphate ions in particular. Conversely, the aqueous species in the alteration solutions (mainly anions) form complexes with the actinides and rare earths; this phenomenon is particularly evident with U and Np. The presence of carbonate ions favors this mobility. Plutonium differs from U and Np in that it is adsorbed mainly on colloids formed by glass dissolution, the principal factors governing its chemical evolution in solution. (author). refs., 122 figs., 185 tabs.}
place = {France}
year = {1995}
month = {Oct}
}