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dc.contributor.authorWeerd H van de
dc.contributor.authorLeijnse A
dc.contributor.authorHassanizadeh SM
dc.contributor.authorRichardson-van der Poel MA
dc.date.accessioned2012-12-12T16:29:41Z
dc.date.available2012-12-12T16:29:41Z
dc.date.issued1994-04-30
dc.identifier715206005
dc.identifier.urihttp://hdl.handle.net/10029/258026
dc.description.abstractAbstract niet beschikbaar
dc.description.abstractA study of uranium transport in one of the best studied "natural analogue sites", the Koongarra site of Alligator Rivers uranium deposit (Australia), is carried out. The purpose of this research is to test the simulation package METROPOL, developed at RIVM to simulate transport of radionuclide, over large time scales. At the Koongarra site secondary uranium mineralization and dispersed uranium, is present from the surface down to the base of weathering, some 25 meters deep. In the Koongarra uranium deposit, the transport processes have been going on for a few (1-3) million years, and during this period many climatological, hydrological and geological changes have taken place. Field data show that three layers can be distinguished in the Koongarra area: i) a top layer which is fully weathered, ii) an intermediate layer which is partially weathered (the transition zone) and iii) a lower layer which is unweathered. The groundwater velocities are largest in the transition zone which has been moving downward as the weathering process proceeds. The transport of uranium in the transition zone is simulated with the finite element code METROPOL. It has been adapted to account for the movement of the transition zone and to describe the dissolution of uranium in the orebody by a non-equilibrium relation. In the simulations a qualitatively reasonable agreement between calculated and measured soluble uranium concentration in the present transition zone is achieved. In this study was shown that over large timescales geologic processes may have a large impact on the transport of radionuclides ; over large timescales, the movement of the transition zone will have a large impact on the uranium concentration distribution. The simulation results in this study are stongly influenced by the parameters values, which are difficult to estimate for a period of some million years. The largest uncertainties are associated with the boundary conditions.
dc.description.sponsorshipDGM/SVS EZ
dc.format.extent88 p
dc.language.isoen
dc.relation.ispartofRIVM Rapport 715206005
dc.relation.urlhttp://www.rivm.nl/bibliotheek/rapporten/715206005.html
dc.subject05nl
dc.subjectgrondwaternl
dc.subjectstromingnl
dc.subjecttransportnl
dc.subjectradioactief afvalnl
dc.subjectzoutlaagnl
dc.subjectondergrondse opslagnl
dc.subjectwiskundig modelnl
dc.subjectrisiconl
dc.subjectsimulatienl
dc.subjecturaniumnl
dc.subjectsorptienl
dc.subjectgroundwateren
dc.subjectflowen
dc.subjecttransport processesen
dc.subjectnuclear wasteen
dc.subjectsalt domesen
dc.subjectdisposalen
dc.subjectunderground storageen
dc.subjectmodellingen
dc.subjectrisksen
dc.subjectsimulationen
dc.subjecturaniumen
dc.subjectdispersionen
dc.subjectsorptionen
dc.subjectgeochemistryen
dc.subjectadsorptionen
dc.subjectweatheringen
dc.subjectaustraliaen
dc.subjectkoongarraen
dc.subjectverspreidingen
dc.subjectgeochemieen
dc.subjectadsorptieen
dc.subjectverweringen
dc.subjectaustralieen
dc.titleINTRAVAL phase 2, test case 8, Alligator Rivers Natural Analogue - Modelling of uranium transport in the weathered zone at Koongarra (Australia). Final reporten
dc.title.alternative[INTRAVAL fase 2, test case 8, Alligator Rivers Natuurlijk Analogon - Modellering van uraniumtransport in de verweerde zone in Koongarra (Australie). Eind rapport.]nl
dc.typeReport
dc.contributor.departmentLBG
dc.date.updated2012-12-12T16:29:42Z
html.description.abstractAbstract niet beschikbaar
html.description.abstractA study of uranium transport in one of the best studied "natural analogue sites", the Koongarra site of Alligator Rivers uranium deposit (Australia), is carried out. The purpose of this research is to test the simulation package METROPOL, developed at RIVM to simulate transport of radionuclide, over large time scales. At the Koongarra site secondary uranium mineralization and dispersed uranium, is present from the surface down to the base of weathering, some 25 meters deep. In the Koongarra uranium deposit, the transport processes have been going on for a few (1-3) million years, and during this period many climatological, hydrological and geological changes have taken place. Field data show that three layers can be distinguished in the Koongarra area: i) a top layer which is fully weathered, ii) an intermediate layer which is partially weathered (the transition zone) and iii) a lower layer which is unweathered. The groundwater velocities are largest in the transition zone which has been moving downward as the weathering process proceeds. The transport of uranium in the transition zone is simulated with the finite element code METROPOL. It has been adapted to account for the movement of the transition zone and to describe the dissolution of uranium in the orebody by a non-equilibrium relation. In the simulations a qualitatively reasonable agreement between calculated and measured soluble uranium concentration in the present transition zone is achieved. In this study was shown that over large timescales geologic processes may have a large impact on the transport of radionuclides ; over large timescales, the movement of the transition zone will have a large impact on the uranium concentration distribution. The simulation results in this study are stongly influenced by the parameters values, which are difficult to estimate for a period of some million years. The largest uncertainties are associated with the boundary conditions.


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