scholarly journals Measurement and modelling of reactive transport in geological barriers for nuclear waste containment

2015 ◽  
Vol 17 (45) ◽  
pp. 30577-30589 ◽  
Author(s):  
Qingrong Xiong ◽  
Claudia Joseph ◽  
Katja Schmeide ◽  
Andrey P. Jivkov
Keyword(s):  
Nuclear Waste ◽  
Reactive Transport ◽  
Unit Cell ◽  
Pore System ◽  
Neighbouring Cell ◽  
Waste Containment ◽  
Central Particle ◽  
Diffusion Paths ◽  
System Information ◽  
Potential Diffusion

Unit cell illustrating potential diffusion paths (bonds, yellow and red) in the neighbourhood of central particle (green); these join neighbouring cell faces and show where elongated pores may be assigned to the experimental pore system information.

Experimental study and modeling of uranium (VI) transport through ferrous olivine rock columns

2000 ◽  
Vol 88 (9-11) ◽  
Author(s):  
M. Rovira ◽  
F.Z. El Aamrani ◽  
L. Duro ◽  
Ignasi Casas ◽  
Joan de Pablo ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Reactive Transport ◽  
Calculated Data ◽  
Buffering Capacity ◽  
Retardation Factor ◽  
Reactive Transport Modeling ◽  
Redox Active ◽  
Different Types ◽  
Free Media ◽  
Waste Repositories

The Lovasjärvi intrusion (SE-Finland) contents a high percentage of ferrous olivine (> 65%). This material has been suggested as a redox-active backfill-additive in deep nuclear waste repositories, due to the large Fe(II) proportion in its mineral composition. In order to understand the processes involved in the redox buffering capacity of this material the transport of uranium (VI) through olivine columns was studied. The results showed considerable retardation factor for the U(VI), particularly in carbonate-free media. The experimental data were simulated by means of reactive transport modeling. The best agreement between the experimental and calculated data was obtained considering that the interaction of U(VI) with the olivine surface occurred at two different types of sorption sites. One type accounts for the sorption capacity of the olivine mineral, and a second type accounts for the sorption on amorphous Fe(OH)

From Nanocomposite Aerogels to Glass Ceramics for Nuclear Wastes Containment

2011 ◽  
Vol 172-174 ◽  
pp. 791-796 ◽  
Author(s):  
Thierry Woignier ◽  
Jerome Reynes ◽  
Sylvie Calas
Keyword(s):  
Viscous Flow ◽  
Thermal Shock ◽  
Nuclear Waste ◽  
High Resistance ◽  
Solid Phase ◽  
Glass Ceramics ◽  
Chemical Species ◽  
Host Matrix ◽  
Waste Containment ◽  
Two Phases

Nanocomposite aerogel is proposed as a host matrix for the synthesis of glass ceramics. The large porosity is used as a sponge to incorporate chemical species getting a two phases material. We describe the steps of the synthesis of glass ceramics for nuclear waste containment, from nanocomposite aerogels loaded with actinides surrogates (Ce and Nd). The glass synthesis is obtained without melting, by a control of several solid phase transformations: sintering, viscous flow, crystallization and foaming. Thanks to their high resistance to thermal shock and water corrosion, these glass ceramics are certainly good candidates as actinides containment materials.

scholarly journals Reactive transport calculations to evaluate sulphide fluxes in the near-field of a SF/HLW repository

2019 ◽  
Vol 98 ◽  
pp. 10005
Author(s):  
Marek Pękala ◽  
Paul Wersin ◽  
Veerle Cloet ◽  
Nikitas Diomidis
Keyword(s):  
Reactive Transport ◽  
Spent Nuclear Fuel ◽  
Near Field ◽  
Opalinus Clay ◽  
High Level Waste ◽  
Waste Containment ◽  
Geological Repository ◽  
High Level ◽  
Reducing Bacteria ◽  
Hlw Repository

Radioactive waste is planned to be disposed in a deep geological repository in the Opalinus Clay (OPA) rock formation in Switzerland. Cu coating of the steel disposal canister is considered as potential a measure to ensure complete waste containment of spent nuclear fuel (SF) and vitrified high-level waste (HLW) or a period of 100,000 years. Sulphide is a potential corroding agent to Cu under reducing redox conditions. Background dissolved sulphide concentrations in pristine OPA are low, likely controlled by equilibrium with pyrite. At such concentrations, sulphide-assisted corrosion of Cu would be negligible. However, the possibility exists that sulphate reducing bacteria (SRB) might thrive at discrete locations of the repository’s near-field. The activity of SRB might then lead to significantly higher dissolved sulphide concentrations. The objective of this work is to employ reactive transport calculations to evaluate sulphide fluxes in the near-field of the SF/HLW repository in the OPA. Cu canister corrosion due to sulphide fluxes is also simplistically evaluated.

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