Laboratory studies of the diffusive transport of 137Cs and 60Co through potential waste repository soils

Itakura, Takashi; Airey, David; Leo, Chin Jian; Payne, Timothy E.; McOrist, G. D.

doi:10.1016/j.jenvrad.2010.04.015

Cited by 9 publications

(3 citation statements)

References 29 publications

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“…Within the DGR, clay engineered barriers, usually placed between the metal canister containing the radioactive waste and external concrete barriers play a significant role in radionuclide retention. Clays have low permeability and diffusivity, high sorption capacity and strong buffering properties [4][5][6]. Among the clays used for this purpose, smectites are generally considered to be the most efficient, due to their ability to undergo strain without fracturing, their low hydraulic conductivity, high cation sorption capacity, and ability to expand and enter into close contact with both waste and rock [7].…”

Section: Introductionmentioning

confidence: 99%

Examination of competitive lanthanide sorption onto smectites and its significance in the management of radioactive waste

Galunin

Alba

Santos

et al. 2011

Journal of Hazardous Materials

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The competitive effect of La and Lu (analogues of radionuclides appearing in radioactive waste) in the sorption in four smectites was examined. Sorption and desorption distribution coefficients (K(d); K(d,des)), and desorption rates (R(des)) were determined from batch tests in two media: deionized water and, to consider the influence of cement leachates, 0.02 mol L(-1) Ca. The competitive effect was lower when high-affinity sites were available, as in the water medium at the lowest range of initial lanthanide concentration, with high K(d) for La and for Lu (5-63×10(4) L kg(-1)). Lower K(d) was measured at higher initial concentrations and in the Ca medium, where Lu showed a stronger competitive effect. This was confirmed by fitting the sorption data to a two-solute Langmuir isotherm. The desorption data indicated that sorption was virtually irreversible for the scenarios with high sorption, with an excellent correlation between K(d) and K(d,des) (R(2) around 0.9 for the two lanthanides). Assuming that radioactive waste is a mixture of radionuclides, and that Ca ions will be provided by the cement leachates, this would reduce the retention capacity of clay engineered barriers.

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Section: Introductionmentioning

confidence: 99%

Examination of competitive lanthanide sorption onto smectites and its significance in the management of radioactive waste

Galunin

Alba

Santos

et al. 2011

Journal of Hazardous Materials

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“…Migration of Co and Cs radionuclides in soil/groundwater system is important for safety disposal radioactive waste containing of these nuclides. Investigations on the behavior of radioactive Cs and Co in soil are addressed in many publications (Xiangke et al, 1999;Hakem et al, 2000;Shihab et al, 2001;Solovitch-Vella and Garnier, 2006;Itakura et al, 2010;Seliman et al, 2010Seliman et al, , 2012. Those publications determined some factors affecting the movement of radiocesium or/and radiocobalt in soil.…”

Section: Introductionmentioning

confidence: 99%

Modeling of 137Cs and 60Co transport in calcareous soils by groundwater

Ramzi¹

2014

J. Soil Sci. Environ. Manage.

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The fate of transport of radionuclides is one of the most important factors to be considered for the safety assessment of repositories of radioactive wastes in porous media. Laboratory batch and column experiments were investigated to assess the transport of 137 Cs and 60 Co in calcareous loam and clay soils leached with groundwater (GW) using convection-dispersion equation model (CDE). Fractionation of Cs and Co in eight sequential fractions in the soils was also measured. Results showed that the distribution coefficient (Kd) values for 137 Cs found to be much more as compared to 60 Co. It was ranged from 20 to 395 ml/g, depending on soil and radionuclide characteristics. The CDE model provided a fairly good fit to the experimental breakthrough curves (BTCs) of both solutes. The retardation factor (R) was 821 and 118 for 137 Cs, while it was 65 and 88 for 60 Co, for both soils, respectively. The dispersion coefficient (D) was 2.0 and 2.8 for Cs, and 0.6 and 0.7 cm 2 /min for Co for loam and clay soils, respectively. The silt+clay was the major soil fraction in retaining Cs followed by sand fraction, for both soils, while the carbonate was the major soil fraction in retaining Co followed by silt+clay, Fe oxides, and sand for loam soil, and silt+clay, sand and Fe oxides for clay soil. No large change was observed in 137 Cs retaining with leaching. The leaching consistently reduced the magnitude of 60 Co bound to carbonate and increased fraction bound to silt+clay.

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“…Within the DGR, clay-engineered barriers, which are usually placed between the metal canister containing the radioactive waste and external concrete barriers, play a major role in radionuclide retention. The clay minerals used tend to have low permeability and diffusivity, a high sorption capacity, and strong buffering properties (Meunier et al, 1998;Landais, 2006;Itakura et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition

et al. 2013

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Laboratory studies of the diffusive transport of 137Cs and 60Co through potential waste repository soils

Cited by 9 publications

References 29 publications

Examination of competitive lanthanide sorption onto smectites and its significance in the management of radioactive waste

Examination of competitive lanthanide sorption onto smectites and its significance in the management of radioactive waste

Modeling of 137Cs and 60Co transport in calcareous soils by groundwater

Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition

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