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Haw-glass dissolution and radionuclide release: mechanism - modelling - source term

Abstract

Important release controlling processes are: 1) kinetics of glass matrix dissolution (leaching), 2) formation of secondary alteration products (controlling thermodynamic solubility), 3) sorption on surfaces in the engineered barrier system and 4) formation of mobile species. Quantification of these processes requires assessment of the energetics and dynamics of the various reversible and irreversible processes within an overall open non-equilibrium system. Corrosion/dissolution of the waste matrices is not necessarily associated with a proportional release of radionuclides. The formation of new secondary phases, such as silicates, molybdates, uranates, carbonates... establishes a new geochemical barrier for re-immobilization of radionuclides dissolved from the waste matrices. The presence of iron (corroding canisters during glass alteration) reduces the solution concentration of redox sensitive radionuclides. Consequently, the container, after being corroded, constitutes an important geochemical barrier for radionuclide re-immobilization. Geochemical modelling of the long-term behaviour of glasses must be performed in an integrated way, considering simultaneous reactions of the glass, of container corrosion, of repository rock and of backfill material. Until now, only few attempts were made for integral systems modelling. (A.C.)
Authors:
Grambow, B [1] 
  1. Forschungszentrum Karlsruhe, Institut fur Nukleare, Karlsruhe (Germany)
Publication Date:
Jul 01, 1997
Product Type:
Conference
Report Number:
INIS-FR-1519
Resource Relation:
Conference: CEA/Valrho summer session. Glass scientific research for high performance containment, Universite d'ete CEA/Valrho. Le Verre: recherche scientifique pour un confinement de haute performance, Mejannes-Le-Clap (France), 31 Aug - 7 Sep 1997; Other Information: 14 refs; PBD: 1997
Subject:
36 MATERIALS SCIENCE; COMPUTERIZED SIMULATION; CORROSION PRODUCTS; GLASS; LEACHING; RADIONUCLIDE MIGRATION
OSTI ID:
20327220
Country of Origin:
France
Language:
English
Other Identifying Numbers:
TRN: FR0203230016385
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
11 pages
Announcement Date:

Citation Formats

Grambow, B. Haw-glass dissolution and radionuclide release: mechanism - modelling - source term. France: N. p., 1997. Web.
Grambow, B. Haw-glass dissolution and radionuclide release: mechanism - modelling - source term. France.
Grambow, B. 1997. "Haw-glass dissolution and radionuclide release: mechanism - modelling - source term." France.
@misc{etde_20327220,
title = {Haw-glass dissolution and radionuclide release: mechanism - modelling - source term}
author = {Grambow, B}
abstractNote = {Important release controlling processes are: 1) kinetics of glass matrix dissolution (leaching), 2) formation of secondary alteration products (controlling thermodynamic solubility), 3) sorption on surfaces in the engineered barrier system and 4) formation of mobile species. Quantification of these processes requires assessment of the energetics and dynamics of the various reversible and irreversible processes within an overall open non-equilibrium system. Corrosion/dissolution of the waste matrices is not necessarily associated with a proportional release of radionuclides. The formation of new secondary phases, such as silicates, molybdates, uranates, carbonates... establishes a new geochemical barrier for re-immobilization of radionuclides dissolved from the waste matrices. The presence of iron (corroding canisters during glass alteration) reduces the solution concentration of redox sensitive radionuclides. Consequently, the container, after being corroded, constitutes an important geochemical barrier for radionuclide re-immobilization. Geochemical modelling of the long-term behaviour of glasses must be performed in an integrated way, considering simultaneous reactions of the glass, of container corrosion, of repository rock and of backfill material. Until now, only few attempts were made for integral systems modelling. (A.C.)}
place = {France}
year = {1997}
month = {Jul}
}