Speciation Analysis of Radionuclides in the Environment - NSK-B SPECIATION project report 2009 (original) (raw)
Related papers
Speciation analysis of 129I, 137Cs, 232Th, 238U, 239Pu and 240Pu in environmental soil and sediment
Applied Radiation and Isotopes, 2012
The environmental mobility and bioavailability of radionuclides are related to their physicochemical forms, namely species. We here present a speciation analysis of important radionuclides including 129 I (also 127 I), 137 Cs, 232 Th, 238 U and plutonium isotopes ( 239 Pu and 240 Pu) in soil (IAEA-375) and sediment (NIST-4354) standard reference materials and two fresh sediment samples from Øvre Heimdalsvatnet Lake, Norway. A modified sequential extraction protocol was used for the speciation analysis of these samples to obtain fractionation information of target radionuclides. Analytical results reveal that the partitioning behaviour, and thus the potential mobility and bioavailability, are exclusively featured for the individual radionuclide. Iodine is relatively mobile and readily binds to organic matter, while plutonium is mainly bound to both organic matter and nitric acid leachable fractions. Thorium is predominated in nitric acid leachable fraction and caesium is primarily observed in nitric acid and aqua regia leachable fractions and residue. Our analytical results reveal that around 50% of uranium might still remain in the residue which could not be extracted with aggressive acid, namely, aqua regia.
A procedure for the sequential determination of radionuclides in soil and sediment samples
Journal of Radioanalytical and Nuclear Chemistry, 2017
We present a new radiochemical procedure for the sequential determination of Sr, Am, Pu, Th and U radionuclides. For the validation, seven IAEA certified reference materials were analyzed for 239 Pu, 240 Pu, 241 Pu, 238 U and 232 Th isotopes by ICP-MS, 243 Am by alpha spectrometry and 90 Sr by low level gas proportional counting. The sequential method was then used for determining the radionuclide profiles in one sediment core collected in the River Rhine, near Augst, downstream of the Swiss nuclear power plants.
Chemical Speciation Analysis and Environmental Behaviour of 127I and 129I
2011
This thesis deals with chemical speciation analysis and behaviour of the anthropogenic radioisotope I as well as stable iodine I in environmental samples such as freshwater, seawater, soils, sediments and seaweed. The behaviour and chemical speciation of iodine (I and I) in environmental samples are very complex and strongly dependent on several factors, such as water/soil/sediment chemistry, seaweed type, different pH, Eh, quantity and quality of organic matter, microbiological activity as well as differences in contaminant origin. The I isotope, where the main inventory has been present in the biosphere for a relatively short time, may not show the same behaviour as the stable I isotope. The present study illustrates this. Chemical speciation analysis of I and I as iodide, iodate and total inorganic iodine in seawater samples from the Baltic Proper, Skagerrak and Kattegat has been carried out. The general trend in variability of the iodide and iodate speciation of the two iodine i...
Journal of Environmental Radioactivity, 2001
The aim of the present study was to determine the forms of Cs, Sr and Pu occurring in di!erent soil horizons using sequential extraction of samples taken from four sites located along a pollution gradient from the copper}nickel smelter at Monchegorsk in the Kola Peninsula, Russia, and from a reference site in Finnish Lapland in 1997. A selective sequential-leaching procedure was employed using a modi"cation of the method of Tessier, Cambell and Bisson ((1979). Analytical Chemistry, 51, 844}851). For Cs the organic (O) and uppermost mineral (E1) layer were studied, for Sr and Pu only the uppermost organic layer (Of). The fraction of Cs occurring in readily exchangeable form in the organic layer was about 50% at the reference site and decreased as a function of pollution, being 15% at the most polluted site in the Kola Peninsula. There was a clear positive correlation in the O layer between the distance from the smelter and the percentage of Cs extracted in the readily exchangeable fraction (Spearman correlation r "0.7805, p"0.0001), whereas in the E1 layer no correlation was evident. The distribution of Sr in the Of layer was similar at all sites, with the highest amounts occurring in exchangeable form and bound to organic matter, whereas stable Sr showed a somewhat di!erent distribution with the highest amount in the oxide fraction. Most of the Pu was bound to organic matter. Chemical pollution a!ected the exchangeable fraction of Pu, 0265-931X/00/$ -see front matter 2000 Elsevier Science Ltd. All rights reserved. PII: S 0 2 6 5 -9 3 1 X ( 0 0 ) 0 0 1 0 3 -X which was about 1% at the most polluted site and 4}6% at the other sites.
Environmental Science & Technology, 2002
Quadrupole inductively coupled plasma mass spectrometry has been used to rapidly establish the chronology of recent aquatic sediments via measurements of the activities of 239 Pu, 240 Pu, and the atom ratio 240 Pu/ 239 Pu. Following addition of 0.007 Bq of a 242 Pu spike isotope, Pu is leached from 3-20 g aliquots of dry-ashed sediments with HNO 3. A selective anion exchanger is used to preconcentrate Pu into ∼2 mL aliquots, which are directly analyzed using a pneumatic nebulizer and double-pass spraychamber operating at 60 µL/min solution uptake rate. The ICPMS data collection is performed for 10 min per sample. The U concentrations were 0.01-0.05 µg/L in the analyzed solutions, and the interference of 238 U 1 H + upon 239 Pu + was negligible. The method has been applied to determining Pu activities, inventory, and 240 Pu/ 239 Pu in a complete sediment core from Old Woman Creek (Huron, OH). The Pu activity profiles, obtained in ∼6 h of instrumental measurement time, are in agreement with a γ spectrometric 137 Cs profile. Peak 239+240 Pu and 137 Cs activities in the core were 1.60 (0.02 and 47.8 (0.8 Bq/kg, respectively; inventories were 108 (2 Bq/m 2 239+240 Pu and 2710 (40 Bq/m 2 137 Cs. Detection limits, based upon the analysis of 20 g samples, were 0.004 Bq/kg 239 Pu, 0.012 Bq/kg 240 Pu, and 0.012 Bq/kg 239+240 Pu. 240 Pu/ 239 Pu atom ratios of 0.16-0.19 were obtained for all core intervals containing detectable Pu, which indicates that global fallout is the source of these radionuclides.
scientific article, 2014
Distributions of 239,240Pu, 238Pu and 137Cs activity concentrations in the cores of sediments in the shallow lake, flooded and upland forest soils taken in the vicinity of Vilnius city were analyzed. The radiochemical, alpha-spectrometric and mass spectrometric methods were used for the plutonium evaluation and c-spectrometry was used for the radiocesium evaluation. The only peak of enhanced radionuclide activity concentrations was determined for the lake bottomsediments, whereas vertical profiles of the radionuclide activity concentrations in flooded and upland forest soil cores were distinguished by two peaks. The obtained values of the activity concentration ratio 238Pu/239,240Pu and the isotopic ratio 240Pu/239Pu indicated that the global fallout was a source of plutonium in the investigated environment. Chernobyl derived radiocesium was detected solely in the surface layers (2–11 cm) of the studied sample cores.The contribution of the Chernobyl deposits amounted to about 2.26, 6.11 and 20.9 % of the total radiocesiuminventory in the bottom sediments, the upland soil and flooded soil, respectively.
Determination of alpha-emitting Pu isotopes in environmental samples
The Analyst, 2002
This paper presents an improved radiochemical procedure for the determination of alpha-emitting Pu isotopes in environmental samples (soils, sediments, vegetation) by alpha-particle spectrometry. Quantitative Pu recovery yields were obtained (average 60%), 0.1 mBq being the average minimum detectable activity by the complete technique. Special efforts were made to ensure the removal of traces of different natural alpha-emitting radionuclides, which can interfere with the correct determination of 239+240 Pu and 238 Pu concentrations. The radiochemical procedure was validated by application to reference material and by participation in intercomparison exercises. This radiochemical procedure was applied to the different layers of a high-resolution sediment core taken from a lake in Sweden. The 239+240 Pu and 238 Pu/ 239+240 Pu profiles obtained in the high-resolution sediment core correctly reproduced the expected evolution of these quantities as observed historically in the atmosphere, validating the procedure for this purpose and showing the power of these radionuclides for dating purposes.
Mobilisation of 137Cs and 90Sr from sediments: potential sources to arctic waters
Sci Total Envir, 1997
Tracer studies ('34Cs and '?3r) have been used to investigate the kinetics of sorption and mobilisation of radionuclides from marine sediments. Distribution coefficients (K, ml g-') for 134Cs in seawater-sediment systems varied with contact time, mixing conditions, sediment type, and salinity, and appeared to be correlated with cation exchange capacity. After 1 year contact time under static conditions, K, for 134Cs ranged from 740 to 1680 ml g-'. Extraction studies showed that the majority of 134Cs was strongly bound to sediment components, although a small fraction (l-10%) was easily displaced and remained in dynamic equilibrium with soluble species. Kinetic modelling using a simple box model indicated that the uptake of ionic Cs to sediments could be described by a two-component function. The relatively fast component probably reflects diffusion through the sediment-water microlayer followed by surface sorption to sediment (ion exchange). Rate constants for transfer between seawater and the exchangeable fraction were similar for the different sediments, 0.23 f 0.03 d-t for uptake and 0.12 f 0.04 dd' for removal. The slow component is thought to represent strong fixation within the mineral lattice; rate constants for fixation showed greater variation, ranging from 0.01 to 0.1 dd'. Ionic ?Sr was rather conservative in seawater, showing little transfer to sediments: K, was 11 + 2 ml g-r. Furthermore, *'Sr bound to sediments by ion exchange was easily displaced. Sequential extraction of Irish Sea and Stepovogo sediments indicated, however, that 90Sr was rather less mobile than the ionic tracer. This might reflect the presence of different WSr species in the discharge (i.e. non-ionic) or a different water-sediment interaction mechanism in the natural environment. For both radionuclides, K, in freshwater was a factor of 100 higher than in seawater, indicating that r3'Cs and 90Sr can be mobilised if freshwater sediments are transferred to the marine environment. 0 1997 Elsevier Science B.V.