Titre du document / Document title

Mobilization of thorium, radium and radon radionuclides in ground water by successive alpha-recoils

Auteur(s) / Author(s)

HONGBING SUN ; SEMKOW T. M. ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

Department of Geological and Marine Sciences, Rider University, Lawrenceville, NJ 08648, ETATS-UNIS
Department of Environmental Health and Toxicology, State University of New York at Albany, Albany, NY 12201, ETATS-UNIS

Résumé / Abstract

Alpha-recoil is an important way for the mobilization of α-decay daughters in ground water. The processes of decay and recoil from ²³⁸U to ²²²Rn and from ²³²Th to ²²⁰Rn are successive. The release rates of successive recoils in this study are quantitatively estimated under two extreme conditions: complete adsorption; and no adsorption of recoil elements by the porous medium. The recoil probability, recoil embedding and effective surface area are considered during the analysis. The result of this study shows that the recoil supply rates in the porous medium decrease down the decay chains. For the isotopes within the same decay chains, recoil emanation ratios of daughters to parents are usually greater than I under both end-member conditions. This is consistent with the higher daughter to parent ratios observed in the field measurements. It is also found that the emanation ratios of Th, Ra and Rn show little change with the change of porosity in general. Radon emanation is most efficient at 15-20% porosity under the condition of complete adsorption. The calculated radioactivity ratios of daughters to parents from this study can provide a partial explanation for the disequilibrium of radioactivity of daughters relative to parents observed in natural water. Because of the low solubility of thorium, radium and radon, the emanation rates calculated under the condition of complete adsorption are closer to the natural conditions.

Revue / Journal Title

Journal of hydrology   ISSN 0022-1694   CODEN JHYDA7 

Source / Source

1998, vol. 205, n^o1-2, pp. 126-136 (15 ref.)

Langue / Language

Anglais

Editeur / Publisher

Elsevier Science, Amsterdam, PAYS-BAS  (1963) (Revue)

Mots-clés anglais / English Keywords

thorium ; radium ; radon ; mobilization ; ground water ; adsorption ; probability ; radionucleids ; U-238 ; Rn-222 ; Th-232 ; porosity ; hydrochemistry ;

Mots-clés français / French Keywords

Thorium ; Radium ; Radon ; Mobilisation ; Eau souterraine ; Adsorption ; Probabilité ; Radionucléide ; U 238 ; Rn 222 ; Th 232 ; Porosité ; Hydrochimie ;

Mots-clés espagnols / Spanish Keywords

Torio ; Radio ; Radón ; Agua subterránea ; Adsorción ; Probabilidad ; Radionucleido ; U 238 ; Rn 222 ; Th 232 ; Porosidad ; Hidroquímica ;

Localisation / Location

INIST-CNRS, Cote INIST : 13239, 35400007508964.0100