An analytical procedure has been developed for the age determination of highly enriched uranium samples exploiting the mother/daughter pair 235U/231Pa. Protactinium is separated from bulk uranium through highly selective sorption to silica gel and is subsequently quantified using alpha-spectrometry. The method has been validated using uranium standard reference materials of known ages. It affor...

OBJECTIVES Increased risk of circulatory system diseases (CSDs) was observed in nuclear workers handling uranium and plutonium in Russia and the UK. This work examines the CSD mortality after chronic intake of uranium among 2897 workers (79,892 person-years) at a uranium processing plant (1960-2006) in France. METHODS Cumulative exposure to different uranium compounds, classified by their iso...

A combination of EXAFS, transmission electron microscopy and energy-dispersive X-ray was used to conduct a molecular and atomic analysis of the uranium complexes formed by Acidithiobacillus ferrooxidans. The results demonstrate that this bacterium accumulates uranium as phosphate compounds. We suggest that at toxic levels when the uranium enters the bacterial cells, A. ferrooxidans can detoxify...

An improved sample preparation procedure for trace-levels of lanthanides in uranium-bearing samples was developed. The method involves a simple co-precipitation using Fe(III) carrier in ammonium carbonate medium to remove the uranium matrix. The procedure is an effective initial pre-concentration step for the subsequent extraction chromatographic separations. The applicability of the method was...

The present paper describes the individual analytical methodologies (Thermal Ionization Mass Spectrometry, Inductively Coupled Plasma Mass Spectrometry and Alpha Spectrometry) that were developed for uranium age determination and discusses their advantages and drawbacks. With respect to a potential application of the methods (e.g. Fissile Material Cut-off Treaty), the discussion focuses on high...

The preparation of a family of bis(imido) uranium(VI) complexes stabilized by mono- and bidentate pyrrolyl ancillary ligands is described. X-ray crystallographic studies of dipyrrolylmethane (dpm) derivatives show that the pyrrolyl coordination mode in these uranium(VI) ions is unexpected in comparison to analogous transition metal and lanthanide chemistry. The ability of the coordinated pyrrol...

During the course of geochemical investigations on uraniferous coals and shales it became necessary to determine if dry distillation of these substances would result in the formation of volatile uranium compounds. Several selected substances have been retorted and material balances based on the uranium contents of the original substances and of the retort chars obtained from them indicate that,...

The presence of depleted uranium in the soil of former Yugoslavia after the 1999 conflict raised great public concern all over the world. The so-called Balkan-syndrome is often linked with depleted uranium contamination. An excellent compilation of data about DU and its possible impact on health and environment can be found in the 1999 UNEP report and publications from the Swedish Radiation Pro...

Stimulating the microbially-mediated precipitation of uranium biominerals may be used to treat groundwater contamination at nuclear sites. The majority of studies to date have focussed on the reductive precipitation of uranium as U(IV) by U(VI)- and Fe(III)-reducing bacteria such as Geobacter and Shewanella species, although other mechanisms of uranium removal from solution can occur, including...

A chitosan resin derivatized with 3,4-dihydroxybenzoic acid moiety (CCTS-DHBA resin) was newly synthesized for the collection/concentration of trace uranium by using cross-linked chitosan (CCTS) as base material, and the adsorption behavior of uranium as well as 60 elements on the resin was examined by passing the sample solutions through a mini-column packed with the resin. After the elution o...