Porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency. The Scientific Basis of Nuclear Waste Management 2019-03-07

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Advanced Nuclear Fuel Cycles And Radioactive Waste Management: Nuclear Development

porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency

All data on the fuel cycle schemes considered in this study including mass flows, waste generation, cost data, and other data such as activities, decay heat and neutron sources of spent fuel and high-level waste along time are included in the computer tool and can be displayed. . The samples showed the various element concentration ranges; 0. In a safety case stochastic calculations are often performed to take account of the uncertainty in parameter values. Less than 10% of the chloride is extracted, meaning that the main part of chloride is trapped in the minerals or nonconnected pores. This study aims to benchmark developments of the technique adapted for high salinity low water activity pore waters by: 1 investigating the factors that might influence the results of the isotope diffusive exchange technique for saline solutions through solution-solution experiments; and 2 apply the adapted diffusive exchange method to rock samples previously equilibrated with synthetic solutions of known chemical and isotopic composition.

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Organisation for Economic Co

porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency

Evolution of the activity in the waste as function of time. It is expected that the salinities in the Opalinus Clay of the potential siting regions in Northern Switzerland will not significantly exceed those of the reference porewater of Benken. The significance of the results are discussed with respect to the corresponding current-potential curves of the solutions. Each technical chapter carries its own conclusions. However, this effect is not proportional to the disposed amount of actinides because most actinides are strongly solubility limited.

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(PDF) Extraction of water and solutes from argillaceous rocks for geochemical characterisation: Methods, processes and current understanding

porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency

Overall, disposal in reducing conditions results in very late, i. Mots-clés Contrôle géochimique, transfert, modèle prédictif. The most broadly based case study is that for the chloride profile through the Opalinus Clay in the southern limb of the Mont Terri anticline Fig. . In case of a fast spontaneous back reaction of the molecular irradiation products a temperature increase followed by thermo-mechanical consequences seems possible.

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Diffusion as the main process for mass transport in very low water content argillites: 1. Chloride as a natural tracer for mass transport—Diffusion coefficient and concentration measurements in interstitial water

porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency

Regarding Scheme 2c, the in-pile inventory shown in Figure 2. For a transmutation strategy with multiple recycling of the fuel, the deployment phase takes many decades. The salinized porewater was likely diluted by freshwater, as evidenced by its depleted isotopes and low salinity relative to standard seawater. Finalmente, se presentan algunos ejemplos de técnicas fiables e información, en función del propósito del estudio geoquímico. The price of natural uranium which is an important factor in fuel cycle cost for the reference Scheme 1a has a moderate impact on fuel cycle costs for schemes involving reprocessing and recycling. Also, each waste package is assumed to contain the waste from generating the same amount of electrical energy, i. In particular, they show that it is possible to establish a strategic progression towards a maximal reduction of the waste source term and a maximal use of uranium resources.

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Extraction of water and solutes from argillaceous rocks for geochemical characte

porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency

. As these depend on the amount and composition of the fuel which is reloaded into the reactors, it is necessary to make assumptions regarding the efficiency of the fuel recovery processes. Clay-rich confining units above and below the Opalinus Clay as supplementary migration barriers Above and below the Opalinus Clay, a series of low-permeability clay-rich or evaporitic formations are found between the host rock and the regional Jurassic and Triassic limestone aquifers in Northern Switzerland. Elsevier Waber, Niklaus; Schneeberger, Raphael; Mäder, Urs; Wanner, Christoph 2017. They are strongly partitioned in the continental crust and their average content varies as a function of rock type. Since the actinides are mostly recovered, minor actinide management techniques, in fact, always reduce the total decay heat of the waste. The Uranium-Radium decay chain is dominating the total dose of the performance assessment for salt over a very long time for all three calculated cases.

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Noble Gases as Environmental Tracers in Sediment Porewaters and Stalagmite Fluid Inclusions

porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency

However, for nuclear generated electricity, total cost is dominated by the capital cost component while fuel cycle cost accounts for no more than some 20%. Particularly in a vertical, but also in a lateral, direction these confining units act as supplementary radionuclide transport barriers Nagra b. In this context, it is a consistent finding that several fission products are more mobile than the actinides. Recognising the uncertainty margins on input cost data, the results from the following economic assessments provide relative indicators of differences between alternative schemes rather than absolute cost values. The Stratigraphy of the basin consists of the Cretaceous Mungo River Formation, overlain by the Tertiary Mpundu Formation. Fuel cycle cost is only a small fraction of total nuclear electricity generation cost.

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The isotopic composition of pore

porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency

On the other hand, the readsorption of chloride to the surface of clays seems unlikely; has shown the nonadsorption of the main part of anions and especially chloride, on the surface of clays in natural water, and have shown anion adsorption on the surface of clays only when these anions form complexes with divalent cations. The radionuclides that have migrated through the host clay formation reach the surrounding aquifers. After termination of the disposal in the respective disposal section, the section will be backfilled and sealed to maintain it in a brine-free state. They are generally yellowish brown to reddish brown in color owing to the ferruginous cement present. This means that, for the purpose of the present study, there is no need for a transient modelling.

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Nuclear Energy Agency

porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency

However, this effect is not proportional to the amount of disposed actinides because most of them are strongly solubility limited. Some conditions for this alternative scheme have been chosen arbitrarily. These two cases are a disposal facility for waste coming from fuel cycle 1a and fuel cycle 3cV1. It concerns two water extraction techniques based on vacuum distillation and two pore-water equilibration techniques radial diffusion in liquid phase and diffusive exchange in vapor phase. The present document provides a synthesis of available extract. Coming from this maximum bulk temperature the upper boundary of the heat load for the disposal drifts has been determined.

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Extraction of water and solutes from argillaceous rocks for geochemical characte

porewater extraction from argillaceous rocks for geochemical characterisation oecd publishing nuclear energy agency

Die hydrogeologischen Eigenschaften des Opalinustons, die unter dem Gesichtspunkt der Langzeitsicherheit relevant sind, werden beschrieben und veranschaulicht. It means that chloride can be located 1 in some pores enclosing water with concentrated chloride, 2 in the vicinity of cation compensation sites, near argillaceous layers, and 3 in some minerals. Scheme 1a has the highest maximum calculated dose because all the generated iodine is going into the geological repository. Access to the facility is provided by two shafts. Discussion This discussion section is intended to clarify which role the presented performance assessment results might play with regard to the intent of the project, i. New waste types of advanced fuel cycles have to be investigated carefully before a feasibility of disposal could be attested. Experimental data obtained during transient and steady parts of diffusion allow for the assessment of the diffusion coefficient and initial concentration in pore water, respectively.

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