Plutonium, 137Cs and 90Sr in selected invertebrates from some areas around Chernobyl nuclear power plant

Title:Plutonium, ¹³⁷Cs and ⁹⁰Sr in selected invertebrates from some areas around Chernobyl nuclear power plant

Author: Jerzy W. Mietelski, Svetlana Maksimova, Przemysław Szwałko, Katarzyna Wnuk, Paweł Zagrodzki, Sylwia Błażej, Paweł Gaca, Ewa Tomankiewicz, Olexandr Orlov

Reference: Journal of Environmental Radioactivity, Volume 101, Issue 6, June 2010, Pages 488-493

DOI:http://dx.doi.org/10.1016/j.jenvrad.2008.04.009

Keywords: Plutonium; ⁹⁰Sr; ¹³⁷Cs; Chernobyl; Invertebrates; Radioactive contamination of biota

Abstract: Results are presented for ¹³⁷Cs, ⁹⁰Sr and plutonium activity concentrations in more than 20 samples of terrestrial invertebrates, including species of beetles, ants, spiders and millipedes, collected in the highly contaminated area of the Chernobyl exclusion zone. The majority of samples were collected in Belarus, with some also collected in the Ukraine. Three other samples were collected in an area of lower contamination. Results show that seven samples exceed an activity concentration of 100 kBq/kg (ash weight – a.w.) for ¹³⁷Cs. The maximum activity concentration for this isotope was 1.52 ± 0.08 MBq/kg (a.w.) determined in ants (Formica cynerea). Seven results for ⁹⁰Sr exceeded 100 kBq/kg (a.w.), mostly for millipedes. Relatively high plutonium activity concentrations were found in some ants and earth-boring dung beetles. Analyses of activity ratios showed differences in transfer of radionuclides between species. To reveal the correlation structure of the multivariate data set, the Partial Least-Squares method (PLS) was used. Results of the PLS model suggest that high radiocesium activity concentrations in animal bodies can be expected mainly for relatively small creatures living on the litter surface. In contrast, high strontium activity concentrations can be expected for creatures which conduct their lives within litter, having mixed trophic habits and a moderate lifespan. No clear conclusions could be made for plutonium.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X08000696

Territory contamination with the radionuclides representing the fuel component of Chernobyl fallout

Title: Territory contamination with the radionuclides representing the fuel component of Chernobyl fallout

Author: V.A Kashparov, S.M Lundin, S.I Zvarych, V.I Yoshchenko, S.E Levchuk, Y.V Khomutinin, I.M Maloshtan, V.P Protsak

Reference: Science of The Total Environment, Volume 317, Issues 1–3, 30 December 2003, Pages 105-119

DOI: http://dx.doi.org/10.1016/S0048-9697(03)00336-X

Keywords: Chernobyl accident; Terrestrial density of contamination; Plutonium; Radioactive fallout; Fuel particles

Abstract: The data obtained through a series of experiments were used to specify the correlation of activities of the fuel component radionuclides of Chernobyl fallout and to create the maps of the 30-km Chernobyl zone terrestrial density of contamination with ¹⁵⁴Eu, ²³⁸Pu, ^239+240Pu and ²⁴¹Am (on 01.01.2000). In the year 2000, total inventories of the fuel component radionuclides in the upper 30-cm soil layer of the 30-km Chernobyl zone in Ukraine (outside the ChNPP industrial site, excluding the activity located in the radioactive waste storages and in the cooling pond) were estimated as: ⁹⁰Sr—7.7×10¹⁴ Bq; ¹³⁷Cs—2.8×10¹⁵ Bq; ¹⁵⁴Eu—1.4×10¹³ Bq; ²³⁸Pu—7.2×10¹² Bq; ^239+240Pu—1.5×10¹³ Bq; ²⁴¹Am—1.8×10¹³ Bq. These values correspond to 0.4–0.5% of their amounts in the ChNPP unit 4 at the moment of the accident. The current estimate is 3 times lower than the previous widely-cited estimates. Inventories of the fuel component radionuclides were also estimated in other objects within the 30-km zone and outside it. This allowed more accurate data to be obtained on the magnitude of a relative release of radionuclides in the fuel particles (FP) matrix during the Chernobyl accident outside the ChNPP industrial site. It amounts to 1.5±0.5% of these radionuclides in the reactor, which is 2 times lower than the previous estimates. Two-thirds of the radionuclides release in the FP was deposited on the territory of Ukraine.

URL: http://www.sciencedirect.com/science/article/pii/S004896970300336X

A prognostic estimation of the area contaminated with alpha-emitting transuranium isotopes in Belarus following the Chernobyl accident

Title: A prognostic estimation of the area contaminated with alpha-emitting transuranium isotopes in Belarus following the Chernobyl accident

Author: V.A. Knatko, V.D. Asimova, A.E. Yanush, Yu.N. Golikov, I.I. Ivashkevich, L.A. Kouzmina, Yu.I. Bondar

Reference: Journal of Environmental Radioactivity, Volume 83, Issue 1, 2005, Pages 49-59

DOI: http://dx.doi.org/10.1016/j.jenvrad.2004.07.005

Keywords:Chernobyl accident;^238,239,240Pu and ²⁴¹Am;Belarus

Abstract: As a result of the Chernobyl accident, some regions of Belarus have been contaminated with the plutonium isotopes ^{238,239,240,241}Pu. Considering the importance of the environmental impact of the alpha-emitting radionuclides we have carried out a prognostic estimation of the area contaminated with ^238,239,240Pu and ²⁴¹Am (the latter being a decay product of ²⁴¹Pu) in Belarus. The calculations were made using measurements of ^238,239,240Pu activity concentrations in soil samples from about 600 settlements in the affected region, together with the estimated activity ratio A(²⁴¹Am)/A(^238,239,240Pu). The area contaminated with alpha-emitting transuranium isotopes predicted for the year 2006 has been compared with that estimated for 1986.The results show that by 2006, the area of inhabited districts where contamination with ^238,239,240Pu and ²⁴¹Am exceeds the threshold level of 740 Bq/m², will be 3.7 times larger, reaching approximately 3.5 × 10³ km². Of this, almost 20% will have a contamination level of 1850–3700 Bq/m².

URL: http://www.sciencedirect.com/science/article/pii/S0265931X05000640

Resolving Chernobyl vs. global fallout contributions in soils from Poland using Plutonium atom ratios measured by inductively coupled plasma mass spectrometry

Keywords: Chernobyl; Contamination; Plutonium; Poland; Soils; Isotopic ratios; Inductively coupled plasma, mass spectrometry

Abstract: Plutonium in Polish forest soils and the Bór za Lasem peat bog is resolved between Chernobyl and global fallout contributions via inductively coupled plasma mass spectrometric measurements of ²⁴⁰Pu/²³⁹Pu and ²⁴¹Pu/²³⁹Pu atom ratios in previously prepared NdF₃ α spectrometric sources. Compared to global fallout, Chernobyl Pu exhibits higher abundances of ²⁴⁰Pu and ²⁴¹Pu. The ratios ²⁴⁰Pu/²³⁹Pu and ²⁴¹Pu/²³⁹Pu co-vary and range from 0.186 to 0.348 and 0.0029 to 0.0412, respectively, in forest soils (²⁴¹Pu/²³⁹Pu=0.2407×[²⁴⁰Pu/²³⁹Pu]−0.0413; r²=0.9924). Two-component mixing models are developed to ap portion ^239+240Pu and ²⁴¹Pu activities; various estimates of the percentage of Chernobyl-derived ^239+240Pu activity in forest soils range from <10% to >90% for the sample set. The ²⁴⁰Pu/²³⁹Pu–²⁴¹Pu/²³⁹Pu atom ratio mixing line extrapolates to estimate ²⁴¹Pu/²³⁹Pu and the ²⁴¹Pu/^239+240Pu activity ratio for the Chernobyl source term (0.123±0.007; 83±5; 1 May 1986). Sample ²⁴¹Pu activities, calculated using existing alpha spectrometric ^239+240Pu activities, and the ²⁴⁰Pu/²³⁹Pu and ²⁴¹Pu/²³⁹Pu atom ratios, agree relatively well with previous liquid scintillation spectrometry measurements. Chernobyl Pu is most evident in locations from northeastern Poland. The ²⁴¹Pu activities and/or the ²⁴¹Pu/²³⁹Pu atom ratios are more sensitive than ²⁴⁰Pu/²³⁹Pu or ²³⁸Pu/^239+240Pu activity ratios at detecting small Chernobyl ^239+240Pu inputs, found in southern Poland. The mass spectrometric data show that the ²⁴¹Pu activity is 40–62% Chernobyl-derived in southern Poland, and 58–96% Chernobyl in northeastern Poland. The Bór za Lasem peat bog (49.42° N, 19.75° E), located in the Orawsko-Nowotarska valley of southern Poland, consists of global fallout Pu.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X03002522

Determination of plutonium from different sources in environmental samples using alpha-spectrometry and AMS

Title: Determination of plutonium from different sources in environmental samples using alpha-spectrometry and AMS

Author:　Bisinger, T. ; Hippler, S. ; Michel, R. ; Wacker, L.; Synal, H.-A.

Reference: Nuclear Instruments & Methods in Physics Research, Section B (Beam Interactions with Materials and Atoms) April 2010, vol.268, no.7-8, pp. 1269-72.

DOI: 10.1016/j.nimb.2009.10.150

Keywords: Plutonium; Chernobyl; Fallout; AMS; Alpha-spectrometry

Abstract: A reliable and sensitive method for the determination of plutonium in environmental samples by a combined use of alpha-spectrometry and accelerator mass spectrometry (AMS) is presented. Different environmental samples contaminated with plutonium from the Chernobyl accident and other sources were investigated using both methods. Plutonium was chemically separated using extraction chromatography. As a chemical yield tracer, ²⁴²Pu was applied for both AMS and alpha-spectrometry. After the alpha-spectrometric measurements, the samples were converted to targets suitable for the AMS measurements. AMS was especially chosen in addition to alpha-spectrometry, because it allows the determination of ²⁴⁰Pu/²³⁹Pu isotopic ratios as well as detecting the beta-emitting radionuclide ²⁴¹Pu. Besides the generally used activity ratios of ²³⁸Pu/^239,240Pu, there are now further optional isotopic ratios available using this method. By combining AMS with alpha-spectrometry, all relevant plutonium isotopes can be measured. Thereby a reliable distinction of different sources of plutonium in the environment is possible.

URL: http://www.sciencedirect.com/science/article/pii/S0168583X09011999

Lichen (sp. Cladonia ) as a deposition indicator for transuranium elements investigated with the Chernobyl fallout

Title: Lichen (sp. Cladonia ) as a deposition indicator for transuranium elements investigated with the Chernobyl fallout

Author: Paatero, Jussi / Jaakkola, Timo / Kulmala, Seija

Reference: Journal of Environmental Radioactivity, 38 (2), p.223-247, Jan 1998

doi: 10.1016/S0265-931X(97)00024-6

Kewords: Plutonium, Lichen (Cladonia), Chernobyl fallout

Abstract: The feasibility of employing carpet-forming lichens (sp. Cladonia) as a measure for the deposition of transuranium elements was investigated with the Chernobyl fallout. In Finland, the deposition of these elements after the accident was very uneven. The highest deposition values for ²³⁸Pu, ^239,240Pu, ²⁴¹Am, ²⁴²Cm and ^243,244Cm were 5.7, 3.0, 1.3, 98 and 0.025 Bq m⁻², respectively. The amount of deposited ^239,240Pu was, however, only some percent of the fallout of the nuclear test explosions of the 1950s and the 1960s. Instead, practically no ²⁴²Cm was released into the environment during the weapons’ testing.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X97000246

Deposition of artificial radionuclides from atmospheric Nuclear Weapon Tests estimated by soil inventories in French areas low-impacted by Chernobyl

Title: Deposition of artificial radionuclides from atmospheric Nuclear Weapon Tests estimated by soil inventories in French areas low-impacted by Chernobyl

Author: Le Roux, Gaël / Duffa, Céline / Vray, Françoise / Renaud, Philippe

Reference: Journal of Environmental Radioactivity, 101 (3), p.211-218, Mar 2010

doi: 10.1016/j.jenvrad.2009.10.010

Keywords: Atmospheric deposition; ¹³⁷Cs; Plutonium; Americium; Nuclear Weapon Tests; France

Abstract: Soil inventories of anthropogenic radionuclides were investigated in altitudinal transects in 2 French regions, Savoie and Montagne Noire. Rain was negligible in these 2 areas the days after the Chernobyl accident. Thus anthropogenic radionuclides are coming hypothetically only from Global Fallout following Atmospheric Nuclear Weapon Tests. This is confirmed by the isotopic signatures (²³⁸Pu/^239+240Pu; ¹³⁷Cs/^239+240Pu; and ²⁴¹Am/^239+240Pu) close to Global Fallout value. In Savoie, a peat core age-dated by ²¹⁰Pb_ex confirmed that the main part of deposition of anthropogenic radionuclides occurred during the late sixties and the early seventies. In agreement with previous studies, the anthropogenic radionuclide inventories are well correlated with the annual precipitations. However, this is the first time that a study investigates such a large panel of annual precipitation and therefore of anthropogenic radionuclide deposition. It seems that at high-altitude sites, deposition of artificial radionuclides was higher possibly due to orographic precipitations.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X09002434

Association of dissolved radionuclides released by the Chernobyl accident with colloidal materials in surface water

Title: Association of dissolved radionuclides released by the Chernobyl accident with colloidal materials in surface water

Author: Matsunaga, Takeshi / Nagao, Seiya / Ueno, Takashi / Takeda, Seiji / Amano, Hikaru / Tkachenko, Yu.

Reference: Applied Geochemistry, 19 (10), p.1581-1599, Oct 2004

doi:10.1016/j.apgeochem.2004.02.002

Keywords: radionuclides, 137Cs, 90Sr, Plutonium, colloids

Abstract: The association of dissolved ⁹⁰Sr, ^239,240Pu and ²⁴¹Am with natural colloids was investigated in surface waters in the Chernobyl nuclear accident area. A 4-step ultrafiltration (UF) study (239,240Pu and 76% of ²⁴¹Am are distributed in colloids of the two size fractions larger than 10 kDa (nominal molecular weight limit of the filter, NMWL), while ⁹⁰Sr was found exclusively (85–88%) in the lowest molecular size fraction below 1 kDa (NMWL) for the Sahan River water at the highly contaminated area close to the Chernobyl Nuclear Power Plant (ChNPP). Consistent results were obtained by 2-step fractionation (larger than and smaller than 10 kDa (NMWL)) for river and lake waters including other locations within about 30 km away from ChNPP. It is likely that Pu and Am isotopes were preferentially associated with dissolved organic matter of high molecular size, as suggested by the fact that (i) only a few inorganic elements (Mg, Ca, Sr, Si, Mn, Al) were found in the colloidal size ranges, and (ii) the positive correlation between dissolved organic C (DOC) concentrations and UV absorbance at 280 nm, a broad absorption peak characteristic of humic substances (HS) was found. A model calculation on the complexation of Pu and Am with HS as an organic ligand suggests that the complexed form could be dominant at a low DOC concentration of 1 mgC L⁻¹, that is commonly encountered as a lower limit in fresh surface water. The present results suggest the general importance of natural organic colloids in dictating the chemical form of actinides in the surface aquatic environment.

URL: http://www.experts.scival.com/kanazawa/pubDetail.asp?id=2942700456&o_id=36

ASSESSMENT OF THE RADIONUCLIDE COMPOSITION OF “HOT PARTICLES” SAMPLED IN THE CHERNOBYL NUCLEAR POWER PLANT FOURTH REACTOR UNIT

Title: ASSESSMENT OF THE RADIONUCLIDE COMPOSITION OF “HOT PARTICLES” SAMPLED IN THE CHERNOBYL NUCLEAR POWER PLANT FOURTH REACTOR UNIT

Author: Farfan, E. / Jannik, T. / Marra, J.

Reference: HEALTH PHYSICS JOURNAL, Oct 2011

Keywords: 21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; AMERICIUM; BURNUP; CESIUM; CESIUM ISOTOPES; CONFINEMENT; CURIUM; EUROPIUM; NUCLEAR POWER PLANTS; PLUTONIUM; RADIOISOTOPES; SHELTERS

Abstract: Fuel-containing materials sampled from within the Chernobyl Nuclear Power Plant (ChNPP) 4th Reactor Unit Confinement Shelter were spectroscopically studied for gamma and alpha content. Isotopic ratios for cesium, europium, plutonium, americium, and curium were identified and the fuel burnup in these samples was determined. A systematic deviation in the burnup values based on the cesium isotopes, in comparison with other radionuclides, was observed. The conducted studies were the first ever performed to demonstrate the presence of significant quantities of {sup 242}Cm and {sup 243}Cm. It was determined that there was a systematic underestimation of activities of transuranic radionuclides in fuel samples from inside of the ChNPP Confinement Shelter, starting from {sup 241}Am (and going higher), in comparison with the theoretical calculations.

URL: http://www.osti.gov/bridge/product.biblio.jsp?query_id=2&page=0&osti_id=1024191

Estimating the exposure of small mammals at three sites within the Chernobyl exclusion zone – a test application of the ERICA Tool

• Title: Estimating the exposure of small mammals at three sites within the Chernobyl exclusion zone – a test application of the ERICA Tool

Author: Beresford, N.A. / Gaschak, S. / Barnett, C.L. / Howard, B.J. / Chizhevsky, I. / Strømman, G. / Oughton, D.H. / (…) / Copplestone, D.

Reference:  Journal of Environmental Radioactivity, 99 (9), p.1496-1502, Sep 2008

doi: 10.1016/j.jenvrad.2008.03.002

Keywords:Thermoluminescent dosimeter; External dose rate; ERICA; Plutonium; Caesium; Strontium; Small mammals; Chernobyl

Abstract: An essential step in the development of any modelling tool is the validation of its predictions. This paper describes a study conducted within the Chernobyl exclusion zone to acquire data to conduct an independent test of the predictions of the ERICA Tool which is designed for use in assessments of radiological risk to the environment.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X08000477