137Cs, 40K, 90Sr, 238, 239+240Pu, 241Am and 243+244Cm in forest litter and their transfer to some species of insects and plants in boreal forests: Three case studies

Results for ¹³⁷Cs, ⁴⁰K, ⁹⁰Sr, ^238,239+240Pu, ²⁴¹Am and ^243+244Cm measurements in plant, insects and forest litter samples collected at three sites in Poland are presented. New results are compared with some existing data for locations examined during previous studies. Insect samples were introduced now for the first time. Relatively high activities of ⁹⁰Sr were noticed for spruce bark beetle (Ips typographus) and those for ¹³⁷Cs, plutonium and ²⁴¹Am for forest dung beetle (Anoplotrupes stercorosus). Faster than caused by physical decay decrease of radiocesium activity was noticed for the majority of plant and litter samples. The results for ^239+240Pu for litter were similar to previous results, but the activities of ²³⁸Pu were smaller. The activity ratio between ²⁴¹Am and ^239+240Pu was found lower than expected for known proportions between global and Chernobyl fallout. Thus a kind of dynamic behavior of Pu and Am in the forest ecosystem is concluded. Transfer factors and aggregation coefficients were estimated and discussed for both plants and insects as well as between insects and the part of plants (or litter) they feed on. Many of them were never presented before.The authors are thankful to the Polish State Committee for Scientific Research for financial support of this investigation, Grant No. PG04 07520.     

Determination of 137Cs, 90Sr, 40K radionuclides in food grain and commercial food grain products

Following up transfer of strontium from soil to plants requires determination of isotope in the surface layer of soil and a chosen plant. The most endangered food products are plants including commonly grown grain, which constitutes a basic feeding component for both people and animals. Indeed large amounts of ¹³⁷Cs, ⁹⁰Sr get into organisms of people and animals with the food, therefore determination of radioactivity of elements in food products and animal fodder is very essential. Choice of proper diet allows to limit the level of human organism denaturation. The aim of this paper was to study relocation of ⁹⁰Sr, ¹³⁷Cs, ⁴⁰K isotopes from soil to grain and then from grain to food products. There were investigated soil, wheat, barley, groats, flour, macaroni and breakfast flakes. Based on the obtained results there were calculated effective weighted doses [nSv] from consumption of 1 kg of a product for different age groups.     

Sorption of 14C, 99Tc, 137Cs, 90Sr, 63Ni, and 241Am onto a rock and a fracture-filling material from the Wolsong low- and intermediate-level radioactive waste repository, Gyeongju, Korea

Sorption experiments for radionuclides such as ¹⁴C, ⁹⁹Tc, ¹³⁷Cs, ⁹⁰Sr, ⁶³Ni, and ²⁴¹Am were conducted using two different groundwaters (GM-1 and SS-5) and solid materials (granodiorite and fracture-filling material) sampled from the Wolsong low- and intermediate-level radioactive waste (LILW) repository, Gyeongju, Korea. The distribution coefficients of the radionuclides, K _d’s, were obtained and their sorption properties were discussed for each radionuclide. For all sorbing radionuclides, the K _d values for the fracture-filling material were observed to be higher than those for granodiorite regardless of the groundwater. The K _d values were increased in the sequence ⁹⁹Tc < ¹⁴C < ⁹⁰Sr < ¹³⁷Cs < ⁶³Ni < ²⁴¹Am regardless of sorbent types implying that the sorption of radionuclides onto geological media is affected by their chemical behavior in accordance with geochemical environments. Anionic radionuclides such as ¹⁴C and ⁹⁹Tc showed very low K _d values both for the granodiorite and fracture-filling material. The mineralogical composition of the geological media and groundwater conditions was also observed to be important in the sorption of sorbing radionuclides, especially in the case of strongly sorbing radionuclides.     

Measurement of the radioactivity of 238U, 226Ra, 210Pb, 228Th, 232Th, 228Ra, 137Cs and 40K in tea using gamma-spectrometry

The aim of the present work was to determine the concentration of radionuclides in all kinds of tea available at the local Egyptian market. Radioactivity of the nuclides ²³⁸U, ²²⁶Ra, ²¹⁰Pb, ²²⁸Th, ²³²Th, ²²⁶Ra, ¹³⁷Cs and ⁴⁰K were measured in tea by direct γ-ray spectrometry using HPGe detector and their mean values were 16.0±5.3, 3.1±0.7, 34.3±3.4, 3.4±1.2, 3.0±0.6, 3.1±0.8, 0.9±0.2 and 623±25 Bq·kg⁻¹, respectively.     

Die Methoden zur schnellen Bestimmung wichtiger Radionuklide (89Sr, 90Sr, 131J und 89Cs)

Ohne Zusammenfassung     

90Sr and239+240Pu238Pu241Am in some samples of mushrooms and forest soil from Poland

Strontium-90, plutonium and americium activity concentrations in a few samples of forest soils, some species of mushrooms and fern leaves have been determined. These results are compared with cesium activity concentrations in the same materials obtained in a previous work. Radiochemical procedures are described. The origin of the contamination (Chernobyl accident or nuclear test explosion release) is discussed. The⁹⁰Sr activity concentration ranges from 0.6 Bq/kg (mushroom samples) to 48.4 Bq/kg (fern leaves). For^239+240Pu, it ranges from not detected above background (mushrooms, fern) to 10.8 Bq/kg (humus layer of forest soil). The maximum concentration of²⁴¹Am is found to be 2.4 Bq/kg (humus sample) and for²³⁸Pu it is 0.85 Bq/kg (also in the humus sample).     

Simultaneous analysis of 137Cs, 90Sr, 238Pu and 239+240Pu in Brazilian seawater

Methodologies for simultaneous analysis of ¹³⁷Cs, ⁹⁰Sr, ²³⁸Pu and ^239+240Pu were developed and applied to seawater samples. ¹³⁷Cs levels in Brazilian coastal seawater ranged from 0.12 to 4.7 Bq·m^-3, for ⁹⁰Sr from 2.0 to 8.6 Bq·m^-3, for ^239+240Pu from 0.8 to 4.5 mBq·m^-3 and for ²³⁸Pu it was of 1.9 mBq·m^-3. The artificial radioactivity levels in Brazilian seawater are typical values due to fallout deposition.     

90Sr, 137Cs, 238Pu, 239+240Pu and 241Am levels in terrestrial and marine ecosystems around the Italian base in Antarctica

During the last 14 years the Radioecology Laboratory of Parma University and the General Chemistry Institute of Urbino University collaborated on a radioecological programme having the aim to observe the evolution of antropogenic radioactivity in Antarctica in the period 1987-2001. The artificial radionuclides considered were ⁹⁰Sr, ¹³⁷Cs, ^239+240Pu,²³⁸Pu and ²⁴¹Am. The contamination seems to be higher in the continental environment rather than in the marine one. Mosses, algae and lichens showed the highest values for all radionuclides analyzed. The results prove that the Antarctic continent is interested by radioactive pollution. As far as ¹³⁷Cs is concerned, a progressive decrease was observed.     

238Pu, 239+240Pu, 241Am, 90Sr and 137Cs in mountain soil samples from the Tatra National Park (Poland)

Activity concentrations and inventory for ²³⁸Pu, ^239+240Pu, ²⁴¹Am, ⁹⁰Sr, and ¹³⁷Cs in soil from Tatra Mountains of Poland are presented. Soil samples were collected using 10 cm diameter cores down to 10 cm and sliced into 3 slices. Details of the applied procedure are described with the quality assurance program. The maximum activity concentrations found for various samples were: 1782±13 Bq/kg, 17.4±0.9 Bq/kg, 3.4±0.3 Bq/kg and 84±7 Bq/kg for ¹³⁷Cs, ^239+240Pu, ²⁴¹Am and ⁹⁰Sr, respectively. The maximum cumulated deposition of ^239+240Pu is 201±8 Bq/m². The origin of radionuclides is discussed, based mostly on the observed isotopic ratio of Pu. Significant correlations were found between ^239+240Pu, ²⁴¹Am and ¹³⁷Cs. The effective vertical migration rate seems to be in the order of: ⁹⁰Sr≫Pu>Am>Cs.     

First results studying the transmutation of 129I, 237Np, 238Pu, and 239Pu in the irradiation of an extended natU/Pb-assembly with 2.52 GeV deuterons

An extended U/Pb-assembly was irradiated with an extracted beam of 2.52 GeV deuterons from the Nuclotron accelerator of the Laboratory of High Energies within the JINR in Dubna, Russia. The lay-out of this experiment and first results are reported. The Pb-target (diameter 8.4 cm, length 45.6 cm) is surrounded by a ^natU-blanket (206.4 kg) and used for transmutation studies of hermetically sealed radioactive samples of ¹²⁹I, ²³⁷Np, ²³⁸Pu and ²³⁹Pu. Estimates of transmutation rates were obtained as result of measurements of gamma-activities of the samples. Information about the spatial and energy distribution of neutrons in the volume of the lead target and the uranium blanket was obtained with sets of activation threshold detectors (Al, Y and Au) and solid state nuclear track detectors (SSNTD). An electronic ³He neutron detector was tested on-line. A comparison of experimental data with theoretical model calculations using the MCNPX program was performed yielding satisfactory results. Collaboration “Energy plus Transmutation” This work is dedicated to the cherished memory of Professor Vladimir Pavlovich Perelygin from the JINR in Dubna, Russia.     

Evaluation of measurements of 238Pu, 239Pu and 240Pu in urine at the microbecquerel level using thermal ionization mass spectrometry and alpha-spectrometry at Los Alamos National Laboratory: Results of a two year comparison test (LA-UR-06-8055)

The Intercomparison Studies Program (ISP) at the Oak Ridge National Laboratory (ORNL, Oak Ridge, TN, USA) provides natural-matrix urine quality-assurance/quality-control (QA/QC) samples to radiobioassay analysis laboratories. In 2003, a single laboratory (Los Alamos National Laboratory LANL, Los Alamos NM USA) requested a change in the test-samples provided previously by the ISP. The change was requested to evaluate measurement performance for analyses conducted using thermal-ionization mass spectrometry (TIMS). Radionuclides included ²³⁹Pu at two activity levels (75–150 μBq^·sample⁻¹ and 1200–1600 μBq^·sample⁻¹) and ²³⁸Pu (3700–7400 μBq^·sample⁻¹). In addition, ²⁴⁰Pu was added to the samples so that the ^239+240Pu specific activity was 3700–7400 μBq^·sample⁻¹. In this paper, the results of testing during the period May, 2003 through September, 2005 are presented and discussed.     

Simultaneous determination of238Pu,239+240Pu,241Pu,241Am,242Cm,244Cm,89Sr,and90Sr in vegetation samples,and application to Chernobyl-fallout contaminated grass

A radiochemical procedure is described for the simultaneous determination of²³⁸Pu,^239+240Pu,²⁴¹Pu,²⁴¹Am,²⁴²Cm,²⁴⁴Cm,⁸⁹Sr, and⁹⁰Sr in vegetation samples. The method was applied for the determination of these, radionuclides in grass, collected near Munich after the fallout from the reactor accident at Chernobyl, USSR. The specific activities observed were (in Bq kg^–1 dry weight):²³⁸Pu, 0.077;^239+240Pu, 0.15;²⁴¹Pu, 3.9;²⁴¹Am, 0.031;²⁴²Cm, 3.0;²⁴⁴Cm, 0.008;⁸⁹Sr, 2000;⁹⁰Sr, 99.     

Vertical migration of plutonium-239 + -240, americium-241 and caesium-137 fallout in a forest soil under spruce.

The vertical activity distributions of fallout 238Pu, 239+240Pu, 241Am, 134Cs and 137Cs in a forest soil (Hapludult) were determined at several locations in a spruce stand separately according to their origin (global fallout or Chernobyl fallout). To determine the rate of migration of these radionuclides in each soil horizon, the observed depth profiles of the radionuclides were evaluated with a compartment model. In the top organic horizons (LOf1 and Of2), the migration rates for all radionuclides from both sources were above 0.5 cm per year. In the Oh horizon the migration rates observed for global fallout Pu, Am and Cs were similar (0.2-0.4 cm per year). Compared with Pu, however, the mobility of Am is slightly, but statistically significantly, enhanced. The highest rate in this layer was found for Chernobyl-derived radiocaesium (2 cm per year). In the layers of the mineral horizon (depth 0-2, 2-5 and 5-10 cm) the observed migration rates were very similar for global fallout Pu (0.08-0.7 cm per year) and Am (0.1-2 cm per year). In comparison, the migration rate of global fallout radiocaesium was about half in each layer. The highest rate was observed again for Chernobyl-derived radiocaesium (0.5-3 cm per year).