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Assessment of the relevance of Coffinite formation within the near-field environment of spent nuclear fuel geological disposals

Published online by Cambridge University Press:  21 March 2011

V. Robit-Pointeau ,
C. Poinssot ,
P. Vitorge ,
B. Grambow ,
D. Cui ,
K. Spahiu  and
H. Catalette
V. Robit-Pointeau
Affiliation:
CEA Nuclear0 Energy Division, Department of Physics and Chemistry, DPC/SECR, F-91191 Gif Sur Yvette cedex, France
C. Poinssot
Affiliation:
CEA Nuclear0 Energy Division, Department of Physics and Chemistry, DPC/SECR, F-91191 Gif Sur Yvette cedex, France
P. Vitorge
Affiliation:
CEA Nuclear0 Energy Division, Department of Physics and Chemistry, DPC/SECR, F-91191 Gif Sur Yvette cedex, France
B. Grambow
Affiliation:
SUBATECH, Ecole des Mines de Nantes, 41 rue Alfred Kastler, BP20722, F-44307 Nantes Cedex, France
D. Cui
Affiliation:
Studsvik Nuclear AB, E-61182, Nyköping, Sweden
K. Spahiu
Affiliation:
SKB, P.O.Box 5864 102040, Stockholm, Sweden
H. Catalette
Affiliation:
EDF, R&D division, Les Renardières, Moret sur Loing, France
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Abstract

Experiments were performed in anoxic gloves box in an attempt to synthesise Coffinite both in representative near-field conditions, and in conditions which were expected to favour its precipitation according to thermodynamic calculations. The experimental results did not confirm the predictions. However, a new mineral was observed instead of Coffinite. In addition, accurate characterization of various natural samples demonstrate the permanent presence of U(VI) within Coffinite contradictory to its theoretical composition. Our observations raise the question on the validity and applicability of available –actually estimated- thermodynamic data of Coffinite. Based on kinetic hindrance of Coffinite formation, coffinitization of spent nuclear fuel in geological disposal is not anticipated to be a dominant short term process.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 932: Symposium – Scientific Basis for Nuclear Waste Management XXIX , 2006 , 71.1
Copyright
Copyright © Materials Research Society 2006

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References

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