Reactive transport modeling of uranium 238 and radium 226 in groundwater of the Königstein uranium mine, Germany

Nitzsche, Olaf; Merkel, Broder J.

doi:10.1007/s100400050215

Cited by 19 publications

(17 citation statements)

References 4 publications

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“…However, all of them only incorporate the resolution of the reactive migration in the aqueous phase and do not take into account sequestered isotopes in the solid phase, either in the crystalline lattice or exchanged/adsorbed [28]. These codes have been applied to solve problems of isotope transport in porous or fissured geological media ( 14 C or 36 Cl [15]) without taking into account heterogeneous reactions.…”

Section: Opalinusmentioning

confidence: 99%

“…Box models when considering transport through an equivalent porous media (near field) and fracture [8] 2005 networks (far field). Considered radionuclides are those of long life and high mobility ( 129 I, 36 Cl, 135 Cs, 99 Tc, 79 Se, 93 Mo, 14 C, 126 Sn) plus an actinide chain ( 229 Th, 233 U, 237 Np, 241 Am, 241 Pu, 245 Cm). Transport processes include advection/diffusion.…”

Section: Dossiermentioning

confidence: 99%

“…To avoid carrying out detailed migration calculations for all of the radionuclides in the radiological inventories, only the radionuclides which have a long enough half-life or which migrate fast enough are selected. The list of radionuclides considered in the transport studies include 14 C, 36 135 Cs and 147 Sm. The heaviest actinides (Cm, Am, and Pu) are not considered in simulations because they are strongly retarded by the clay and most of their isotopes are relatively short-lived.…”

Section: Safirmentioning

confidence: 99%

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Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

Juncosa¹,

Font

Delgado

2010

Radiochimica Acta

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Radioactive decay / Coupled problems / Isotopic migration / Repository safety analysis / HLWSummary. Radioactive decay is an important subject to take into account when studying the thermo-hydro-dynamic behavior of the buffer clay material used in the containment of radioactive waste. The modern concepts for the multibarrier design of a repository of high level waste in deep geologic formations consider that once canisters have failed, the buffer clay material must ensure the retention and/or delay of radionuclides within the time framework given in the assessment studies. Within the clay buffer, different chemical species are retarded/fixed according to several physicochemical processes (ion exchange, surface complexation, precipitation, matrix diffusion, ...) but typical approaches do not consider the eventuality that radioactive species change their chemical nature (i.e. phase) thereby affecting their reactive behavior.The radioactive decay of an element takes place independently of the phase (aqueous, solid or gaseous) to which it belongs. This means that, in terms of radionuclide fixation, some geochemical processes will be effective scavengers (for instance mineral precipitation of crystal growth) while others will not (for instance ion exchange and/or sorption).In this contribution we present a reactive radioactive decay model of any number of chemical components including those that belong to decay series. The model, which is named FLOW-DECAY, also takes into account flow and isotopic migration and it has been applied considering a hypothetical model scenario provided by the project ENRESA 2000 and direct comparison with the results generated by the probabilistic code GoldSim. Results indicate that FLOW-DECAY may simulate the decay processes in a similar way that GoldSim, being the differences related to factors associated to code architecture.

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Section: Opalinusmentioning

confidence: 99%

Section: Dossiermentioning

confidence: 99%

Section: Safirmentioning

confidence: 99%

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Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

Juncosa¹,

Font

Delgado

2010

Radiochimica Acta

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“…According to this simplicity only one uranium species was used for modelling of uranium interaction with the rock surface. The interaction and transport modelling was accomplished in the environment of computer code PHREEQC (Parkhurst and Appelo 1999;Nitzsche and Merkel 1999). The interaction of uranium with the surface was modelled via a formal exchange site, and kinetic character of uranium release recognized in experiments was taken into account.…”

Section: Mathematical Modellingmentioning

confidence: 99%

Modelling of uranium release from waste rock pile

Vopálka

Beneš

Doubravova

2006

Uranium in the Environment

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Abstract. Uranium release/uptake on material of waste rock pile No. 66 at Schlema-Alberoda (Saxony, Germany) was studied by both static (batch) and dynamic (column) experiments with the aim to obtain input data for modelling of uranium migration in the pile. Most of the experiments were carried out by radiotracer method using 233 U as the label. An ambiguous influence of humic acid (concentration 10 and 50 mg/L) on the migration of uranium was observed. The column elution experiments were modelled using PHREEQC that enabled to respect the kinetic character of the desorption process.

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“…Zhu et al (2001) carried out multi-component reactive-transport modelling of natural attenuation of an acid groundwater plume at Bear Creek uranium-mill tailings site, USA, which helped to simulate radionuclide migration, including chemical interactions with the solid matrix and double-porosity effects. Modelling of radioactive reactive transport in groundwater at the Königstein uranium mine, Germany, was carried out by Nitzsche and Merkel (1999), which indicated slow migration of uranium. Nair et al (2010) studied the long-term decay-chain transport of uranium in a heterogeneous anisotropic medium of groundwater and identified the necessity for monitoring of short-lived progeny radionuclides apart from their long-lived parents in the groundwater in the vicinity of uranium tailings ponds.…”

Section: Introductionmentioning

confidence: 99%

Groundwater flow and radionuclide decay-chain transport modelling around a proposed uranium tailings pond in India

et al. 2012

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Extensive hydrogeological investigations followed by three-dimensional groundwater flow and contaminant transport modelling were carried out around a proposed uranium tailings pond at Seripalli in Andhra Pradesh, India, to estimate its radiological impact. The hydrogeological parameters and measured groundwater level were used to model the groundwater flow and contaminant transport from the uranium tailings pond using a finite-element-based model. The simulated groundwater level compares reasonably with the observed groundwater level. Subsequently, the transport of longlived radionuclides such as 238 U, 234 U, 230 Th and 226 Ra from the proposed tailings pond was modelled. The ingrowths of progenies were also considered in the modelling. It was observed that these radionuclides move very little from the tailings pond, even at the end of 10,000 y, due to their high distribution coefficients and low groundwater velocities. These concentrations were translated into committed effective dose rates at different distances in the vicinity of the uranium tailings pond. The results indicated that the highest effective dose rate to members of the public along the groundwater flow pathway is 2.5 times lower than the drinking water guideline of 0.1mSv/y, even after a long time period of 10,000 y.

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Reactive transport modeling of uranium 238 and radium 226 in groundwater of the Königstein uranium mine, Germany

Cited by 19 publications

References 4 publications

Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

Modelling of uranium release from waste rock pile

Groundwater flow and radionuclide decay-chain transport modelling around a proposed uranium tailings pond in India

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