Technically enhanced naturally occurring radionuclides (TENORM) in phosphogypsum: Comparison CCRI(II)-S5

Abstract

Within the frame of mutual cooperation between the IAEA and the BIPM, the Consultative Committee for Ionizing Radiation Section II-Measurement of Radionuclides accepted an IAEA-organized interlaboratory comparison in 2008 on the determination of technically enhanced naturally occurring radionuclides in phosphogypsum. The study was piloted by the Chemistry Unit at the IAEA's Laboratories in Seibersdorf (Austria). This report presents the methodology applied in conducting this comparison and the results. Activity results for Pb-210, Ra-226, Th-230, U-234, U-235 and U-238 were reported by three National Metrology Institutes (NMI) and five other expert laboratories or designated institutes. Four different approaches were used to calculate the nominal value of the reported results and associated uncertainties, and the results from each individual participant were evaluated and compared with this nominal reference value. The reported measurement results evaluation demonstrated agreement amongst the participating laboratories.

Towards zero-waste valorisation of rare-earth-containing industrial process residues: a critical review

“…Phosphogypsum may contain specific activities of 226 Ra between one and two orders of magnitude higher than those of natural gypsum, depending on the uranium content of the ore (Menzel, 1968). Due to the enrichment of radionuclides, phosphogypsum is classified as a technologically enhanced naturally occurring radioactive material (TENORM) (Shakhashiro et al, 2010;Tayibi et al, 2009;Gezer et al, 2012). The decay of 226 Ra in the phosphogypsum will result in the formation and reappearance of daughter nuclides and radioactive equilibrium will be re-established.…”