Radiochemical methods used by the IAEA's laboratories at Seibersdorf for the determination of 90Sr, 144Ce and Pu radionuclides in environmental samples collected for the International Chernobyl project

Determination of 90Sr/90Y in Wheat Grains, Soil, and Deposition Samples by TBP Extraction and Cerenkov Counting

“…Table 1 shows the distribution coefficients of some elements for the system 100% TBP/14M HNO 3 reported by Tinker et al (1997 and literature cited therein). After washing the organic phase, yttrium is either stripped with water or with diluted HNO 3 or is precipitated as a hydroxide by the addition of ammonia and ethanol (BMU 2000;LaRosa et al 1992;Tinker et al 1997). The most serious problem related to the extraction of 90 Y with TBP is the coextraction of thorium isotopes, some of them having short-lived daughter nuclides emitting high-energy beta radiation.…”

Radionuclides from Chernobyl hot particles in the environment of North-Eastern Poland - A leaching experiment

“…The refractory fraction samples were ashed in 450°C. For a sub-sample of about 10 g of ash of each one original sample a typical mineralisation procedure [14] was applied next. Tracers ( 6 Pu, 232 U, 243 Am, l48 Gd) were added in all cases prior to the wet mineralisation.…”

“…The separation order was: Cs before any radiochemistry, Th and Pu, Sr, U, rare earths and Am -Cm. Plutonium and thorium were separated after the adjustment of the Pu oxidation step [14] using DOWEX-1 anion exchange pressurised columns [4] when the samples were dissolved in 8 M HNO3. Strontium was separated just from 8 M HNO3 effluent using Sr-resin produced by Eichrom Ltd., and the polyethylene columns long for 9 cm and having 7 mm of inner diameter.…”

“…From the effluent the rare-earths and Am -Cm isotopes were separated using a typical procedure [16] only very slightly modified, as it was described in a previous article [17]. All alpha spectrometric sources were prepared using NdF3 method [18,14], and measured on Silena AlphaQuatrro spectrometer with Canberra PIPS detectors. The w Sr was measured using liquid scintillation spectrometer Wallac Gurdian 1414-003 with Hi-Safe 3 cocktail and plastic, diffuse type vessels.…”

A study of the bioavailability of90Sr,137Cs, and239+240Pu in soils at two locations of Spain affected by different radionuclide contamination events

“…The procedure used for the determination of plutonium is based on an optimization of various methods proposed by other authors [6,7]. The soil samples were calcined at 600 C, and acid digested with HF and HNO 3 .…”