Speciation of radionuclides

Lujaniene G, Lujanas V, Jankunaite D, et al. 1999. Speciation of radionuclides of the Chernobyl origin in aerosol and soil samples. J Environ Radioact 49 107-114. 

This second edition retains the structure of the first edition. It aims to provide a comprehensive review of the current science of speciation, covering relevant methodological, analytical and modelling aspects as well as giving an overview of recent work on speciation in various spheres. It is divided into two parts, the first dealing with the more methodological aspects and the second with specific compartments of the environment, with the speciation of radionuclides, and presents a review of current trends and developments. 

Classical speciation of radionuclides is described in Chapter 13. Methodology for single and sequential extraction of soil to assess radionuclide availability to plants is similar to that used for heavy metals, and has recently been reviewed (Kennedy et al., 1997). Therefore, only recent applications of sequential extraction to speci-ate both natural and anthropogenic nuclides are discussed below. 

Nicholson, S. and Shaw, P.N. (1991) An investigation into the organic speciation of radionuclides in marine organisms. AEA Report EE-0070, Harwell Laboratory, Oxon, UK, 30 pp. 

Pollard, P.M. (1985) A survey of the current potential analytical techniques for the speciation of radionuclides in nuclear waste repository groundwaters and simulation leachates. AERE R.11496. UKAEA Harwell, Oxon, UK, 41 pp. 

Sparkes, S.T., Sanders, T.W. and Long, S.E. (1987) A literature survey of the organic speciation of radionuclides. AERE Report R12487, Harwell, Oxford, UK, 25 pp. 

Good summaries of accepted experimental techniques can be found in the references that are cited for individual radionuclides in the sections below. Nitsche (1991) provides a useful general summary of the principles and techniques of solubility studies. A large number of techniques have been used to characterize the aqueous speciation of radionuclides. These include poten-tiometric, optical absorbance, and vibrational spectroscopy. Silva and Nitsche (1995) summarize the use of conventional optical absorption and laser-based photothermal spectroscopy for detection and characterization of solution species and provide an extensive citation list. A recent review of the uses of Raman and infrared spectroscopy to distinguish various uranyl hydroxy complexes is given by Runde et al. (2002b). 

Runde W., Neu M. P., Condrdson S. D., Ei J., Ein M., Smith D. M., Van-Pelt C. E., and Xu Y. (2002b) Geochemical speciation of radionuclides in soil and solution. In Geochemistry of Soil Radionuclides. SSSA Special Publication Number 59 (eds. P. Zhang and P. Brady). Soil Science Society of America, Madison, Wisconsin, pp. 45-60. 

These observations indicate that the speciation of radionuclides in the atmosphere is dependent on their source, their mechanisms of production and the nature of the particular environment. While some species are gaseous, others are associated to particles with properties and suspension times that are strongly dependent on the particle size and density. 

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