The distribution of depleted uranium contamination in Colonie, NY, USA

Abstract

Uranium oxide particulates were dispersed into the environment from a factory in Colonie (NY, USA) by prevailing winds during the 1960's and '70's. Uranium concentration and isotope ratios from bulk soil samples have been accurately measured using inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) without the need for analyte separation chemistry. The natural range of uranium concentrations in the Colonie soils has been estimated as 0.7 -2.1 µg g -1 , with a geometric mean of 1 µg g -1 ; the contaminated soil samples comprise uranium up to 500 ± 40 µg g -1. A plot of 236 U/ 238 U against 235 U/ 238 U isotopes ratios describes a mixing line between natural uranium and depleted uranium (DU) in bulk soil samples; scatter from this line can be accounted for by heterogeneity in the DU particulate. The end-member of DU compositions aggregated in these bulk samples comprises (2.05 ± 0.06) x10 -3 235 U/ 238 U, (3.2 ± 0.1) x10 -5 236 U/ 238 U, and (7.1 ± 0.3) x10 -6 234 U/ 238 U. The analytical method is sensitive to as little as 50 ng g -1 DU mixed with the natural uranium occurring in these soils. The contamination footprint has been mapped northward from site, and at least one third of the uranium in a soil sample from the surface 5 cm, collected 5.1 km NNW of the site, is DU. The distribution of contamination within the surface soil horizon follows a trend of exponential decrease with depth, which can be approximated by a simple diffusion model. Bioturbation by earthworms can account for dispersal of contaminant from the soil surface, in the form of primary uranium oxide particulates and uranyl species that are sorbed to organic matter. Considering this distribution, the total mass of uranium contamination emitted from the factory is estimated to be c. 4.8 tonnes.

Contribution des isotopes de l’uranium à l’expertise des sources de ce radioélément dans l’environnement

“…Dans l'environnement d'autres installations nucléaires, on observe un marquage de l'environnement en uranium-236. Ainsi, à proximité du site de Colony (New York, USA), les sols témoignent de variations importantes des concentrations en uranium, allant de 0,7-2,1 µg.g -1 dans les sols non-influencés à 500 µg.g -1 dans les sols les plus contaminés par les rejets (Lloyd et al, 2009 …”

Ecological and corrosion behavior of depleted uranium

“…Istraživanja disperzije čestica oksida uranijuma, nastalih tokom sagorevanja otpadnog metala OU, u fabrici za proizvidnju OU u Colonie (NI, USA), procenjeno je, da je najmanje 3,4 t OU deponovano u okruženju fabrike na površini 1 km 2 a da su čestice OU detektovane na udaljenosti od 600 m od fabrike u pravcu dominantnog vetra. U prikupljenim česticama zemljišta i prašine identifikovani su mešoviti oksidi UO 2 +x i U 3 O 8 , 20-64 μm u prečniku [56,57].…”

Pathways of Radioactive Substances in the Environment

“…26 The transport of DU particles will depend on particle properties (i.e., size and density) and on prevailing meteorological conditions. 51 54,55 investigated the dispersion of aerosols formed during the combustion of waste metal at a uranium and DU processing factory in Colonie (NY, USA). The distribution of the DU aerosol was controlled by prevailing winds, with DU contamination found up to 600 m from the factory.…”