Description

The safe disposal of radioactive wastes by burial in deep geological formations requires long-term predictions of the future behaviour of the wastes and their engineered repository. Such predictions can be tested by evaluating processes analogous to those which will occur in a repository, which have been long active in the natural geochemical environment.

The Pocos de Caldas Project is a comprehensive study of two ore deposits in Minas Gerais, Brazil, aimed at looking at uranium and thorium series radionuclide and rare-earth element mobility, the development and movement of redox fronts, and the nature of natural groundwater colloids. A multidisciplinary team of experts from 27 laboratories carried out a fully integrated study of the geology, geomorphology, hydrogeology, geochemistry, hydrochemistry and geomicrobiology of the two sites for nearly four years. This book contains 20 papers covering the detailed findings, with particular emphasis on their significance for radioactive waste disposal, especially on the use of the data in testing models of radionuclide movement. It will interest economic geologists, geochemists and performance assessment modellers involved in the geological disposal of radioactive wastes.

Table of Contents

PART 1. The Pocos de Caldas Project: an introduction and summary of its implications for radioactive waste disposal. The regional geology of the Poços de Caldas alkaline complex: mineralogy and geochemistry of selected nepheline syenites and phonolites. Hydrothermal and supergene uranium mineralization at the Osamu Utsumi mine, Poços de Caldas, Minas Gerais, Brazil. The supergene thorium and rare-earth element deposit at Morro do Ferro, Poços de Caldas, Minas Gerais, Brazil. Origin and growth rates of pitchblende nodules at the Osamu Utsumi mine, Poços de Caldas, Brazil. Isotopic geochemical characterization of selected nepheline syenites and phonolites from the Poços de Caldas alkaline complex, Minas Gerais, Brazil. Geomorphological and hydrogeological features of the Poços de Caldas caldera analogue study sites. Ground water chemistry and geochemical modeling of water-rock interactions at the Osamu Utsumi mine and the Morro do Ferro analogue study sites, Pocos de Caldas, Minas Gerais, Brazil. Natural decay series studies of the redox front system in the Poços de Caldas uranium mineralization. The interpretation of 238U-234U-230Th-226Ra disequilibria produced by rock water interactions. Uranium and thorium isotopes in groundwaters from the Osamu Utsumi mine and Morro do Ferro natural analogue sites, Poços de Caldas, Brazil. Rare-earth elements in groundwaters from the Osamu Utsumi mine and Morro do Ferro analogue study sites, Poços de Caldas, Brazil. Light rare earth elements and natural series radionuclides within the Morro do Ferro. Chemical and physical characterization of suspended particles and colloids in waters from the Osamu Utsumi mine and Morro do Ferro analogue study sites, Poços de Caldas, Brazil. Microbiological analysis at the Poços de Caldas natural analogue study sites. Testing models of trace element geochemistry at Poços de Caldas. Movement of the redox front at the Osamu Utsumi uranium

Details

No. of pages:
614
Language:
English
Copyright:
© 1993
Published:
Imprint:
Elsevier Science
Electronic ISBN:
9780444598912
Print ISBN:
9780444899347

About the editors