Vertical distribution of radionuclides in soil of a grassland site in Chernobyl exclusion zone

Title: Vertical distribution of radionuclides in soil of a grassland site in Chernobyl exclusion zone

Author: Peter Bossew, Michael Gastberger, Herbert Gohla, Peter Hofer, Alexander Hubmer

Keywords: Chernobyl; Radionuclides; Vertical migration in soil

Abstract: Five soil profiles from a site about 8 km SE of the Chernobyl NPP were investigated for the vertical distribution of radionuclides. The average ¹³⁷Cs-inventory at the site is about 2.6 MBq/m² (reference date 1 May 1986). Apart from ¹³⁷Cs, the following radionuclides have been identified (their activity ratios to ¹³⁷Cs in brackets): ¹³⁴Cs (0.537), ¹²⁵Sb (0.068), ⁶⁰Co (0.0022), ¹⁵⁴Eu (0.016), ¹⁵⁵Eu (0.020), ^94gNb (9.5E-5), ^239/240Pu (0.0088), ²³⁸Pu (0.040), ⁹⁰Sr (0.30) and ²⁴¹Am (0.011). Apparent vertical migration velocities are between 0.14 and 0.26 cm/a, apparent dispersion coefficients range from 0.02 to 0.13 cm²/a. The rankings of the velocities v for different radionuclides are (Sr, Cs, Sb, Co, Pu)<AmD, the following rankings have been found: (Nb, Sr, Cs)<Am<Eu, Csp=0.1 level).

URL: http://www.sciencedirect.com/science/article/pii/S0265931X03002364

Distribution and migration of ⁹⁰Sr in components of the Dnieper River basin and the Black Sea ecosystems after the Chernobyl NPP accident

Title: Distribution and migration of ⁹⁰Sr in components of the Dnieper River basin and the Black Sea ecosystems after the Chernobyl NPP accident
Author: N.Yu. Mirzoyeva, V.N. Egorov, G.G. Polikarpov

URL: http://www.sciencedirect.com/science/article/pii/S0265931X13000489

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

Kinetics of dissolution of Chernobyl fuel particles in soil in natural conditions

Keywords: Chernobyl; Fuel particles; Dissolution kinetics; Sr-90; Mobility; Soil

Abstract: Kinetic of fuel particles dissolution under natural environmental conditions has been investigated using the data on ⁹⁰Sr speciation in soils collected from 1995 to 1997 within the Chernobyl nuclear power plant 50 km zone. The dependency of fuel particles dissolution constants on the soil acidity (pH=4–7) has been obtained on the basis of large and statistically reliable experimental data. Results show that between 2 and 21% of ⁹⁰Sr activity is associated with weathering resistant fuel particles. Therefore, these particles would not influence the radiological situation in the near future. The map of the main agrochemical characteristics and the map of the fuel particles dissolution constants have been created for the 30-km zone territory. According to the prognosis of dynamics of fuel particles dissolution in the investigated zone, a radiological situation along the fuel paths of radioactive fallout in present time reached a stable state. An increasing in absolute contents of ⁹⁰Sr mobile forms in neutral soils will be observed in the next 10–20 yr. However, the difference between the maximum level of mobile forms contents and their existing contents will not exceed 20%.

Use of 129I and 137Cs in soils for the estimation of 131I deposition in Belarus as a result of the Chernobyl accident

Keywords: Chernobyl; ¹²⁹I; ¹³¹I; ¹³⁷Cs; Soils

Abstract: Using radioactivity measurements for ¹³¹I and ¹³⁷Cs and nuclear activation analysis (NAA) or accelerator mass spectrometry (AMS) for ¹²⁹I, ratios of ¹³¹I/¹³⁷Cs and ¹²⁹I/¹³⁷Cs have been determined in soils from Belarus. We find that the pre-Chernobyl ratio of ¹²⁹I/¹³⁷Cs in Belarus is significantly larger than expected from nuclear weapons fallout. For the Chernobyl accident, our results support the hypothesis that there was relatively little fractionation of iodine and caesium during migration and deposition of the radioactive cloud. For sites having ¹³⁷Cs >300 Bq/kg, ¹²⁹I can potentially give more reliable retroactive estimates of Chernobyl ¹³¹I deposition. However, our results suggest that ¹³⁷Cs can also give reasonably good (±50%) estimates for ¹³¹I in Belarus.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X01000807

Classification of hot particles from the Chernobyl accident and nuclear weapons detonations by non-destructive methods

Keywords: Hot particles; Chernobyl; Weapons tests; Fallout; Characterisation; Analysis

Abstract: Both after the Chernobyl accident and nuclear weapon detonations, agglomerates of radioactive material, so-called hot particles, were released or formed which show a behaviour in the environment quite different from the activity released in gaseous or aerosol form. The differences in their characteristic properties, in the radionuclide composition and the uranium and actinide contents are described in detail for these particles. While nuclear bomb hot particles (both from fission and fusion bombs) incorporate well detectable trace amounts of ⁶⁰Co and ¹⁵²Eu, these radionuclides are absent in Chernobyl hot particles. In contrast, Chernobyl hot particles contain ¹²⁵Sb and ¹⁴⁴Ce which are absent in atomic bomb HPs. Obvious differences are also observable between fusion and fission bombs’ hot particles (significant differences in ¹⁵²Eu/¹⁵⁵Eu, ¹⁵⁴Eu/¹⁵⁵Eu and ²³⁸Pu/²³⁹Pu ratios) which facilitate the identification of HPs of unknown provensence. The ratio of ²³⁹Pu/²⁴⁰Pu in Chernobyl hot particles could be determined by a non-destructive method at 1 : 1.5. A non-destructive method to determine the content of non-radioactive elements by Kα-emission measurements was developed by which inactive Zr, Nb, Fe and Ni could be verified in the particles.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X01000133

Bioindication of the anthropogenic effects on micropopulations of Pinus sylvestris, L. in the vicinity of a plant for the storage and processing of radioactive waste and in the Chernobyl NPP zone.

Keywords: Bioindication; Pinus sylvestris L.; Chromosome aberrations; Chernobyl accident

Abstract: Results of a comparative analysis of the frequency and spectrum of cytogenetic anomalies are presented for reproductive (seeds) and vegetative (needles) samples taken from Scotch pine (Pinus sylvestris, L.) micropopulations growing at sites with differing levels of radioactive contamination in the Chernobyl NPP 30 km zone, and at the location of a facility for the processing and storage of radioactive wastes (the ‘Radon’ LWPE, near the town of Sosnovy Bor in the Leningrad Region). The data obtained indicate the presence of genotoxic contaminants in the environment of the tree micropopulations. Chemical toxins make the main contribution to the environmental contamination in the Sosnovy Bor area as compared with the influence of ionising radiation in the Chernobyl 30 km zone. The higher radioresistance of seeds of Scotch pine growing on the area of the ‘Radon’ LWPE and in the centre of Sosnovy Bor town was revealed with acute γ-radiation.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X02001224

Fukushima set for epic clean-up

DOI: 10.1038/472146a

Keywords: RADIOISOTOPES ,MARINE pollution, CHERNOBYL,JAPAN, UKRAINE,FUKUSHIMA Daiichi Nuclear Power Plant

Abstract: The article focuses on the clean-up strategies related to the damaged nuclear reactors of Fukushima Daiichi Nuclear Power Plant in Japan. Environmental and radiological health expert at Colorado State University Ward Whicker suggest that sampling efforts in the locations of the nuclear accident are necessary to monitor radionuclides concentration in the marine environment. Moreover, similar strategy at Chernobyl Nuclear Accident in Ukraine in 1986 is being considered.

URL: http://www.nature.com/news/2011/110411/full/472146a.html

Higher Plant Assays for the Detection of Genotoxicity in Air Polluted Environments.

Title: Higher Plant Assays for the Detection of Genotoxicity in Air Polluted Environments.

Author: William F. Grant

Reference: Ecosystem Health, Volume 4, Issue 4, pages 210–229, December 1998

DOI: 10.1046/j.1526-0992.1998.98097.x

Keywords:Genotoxicity,Air pollution

Abstract: Since the beginning of time pollution has been created by human activities. However, the intensity and the severity of the different kinds of pollution have emerged only in the last few decades and many intricate facets have been revealed. It is gradually being recognized that our health and the ecosystem are being severely affected by environmental chemicals that enter the atmosphere. Plants comprise a large portion of our biosphere and constitute a vital link in the food chain. In this review, types of mutagenic chemicals found both indoor and outdoor are given and several higher plant bioassays for screening and monitoring environmental mutagens are discussed. One plant ideal for monitoring and testing for air pollution is Tradescantia. This species has been used to test for mutagenicity of radioisotope-contaminated air following the Chernobyl nuclear accident and monitoring around nuclear power plants. One of the greatest contributions of plant bioassays will be their continued use for ambient air monitoring and testing for genotoxicity which can be carried out on a global scale.

URL: http://onlinelibrary.wiley.com/doi/10.1046/j.1526-0992.1998.98097.x/abstract

Recent sedimentation in the Black Sea: New insights from radionuclide distributions and sulfur isotopes

Title: Recent sedimentation in the Black Sea: New insights from radionuclide distributions and sulfur isotopes.

Author: Yücel, Mustafa; Moore, Willard S.; Butler, Ian B.; Boyce, Adrian; Luther, George W.

Reference: Deep-Sea Research Part I, Oceanographic Research Papers. Aug2012, Vol. 66, p103-113. 11p.

DOI: http://dx.doi.org/10.1016/j.dsr.2012.04.007

Keywords: Black Sea; Sediment; Mass accumulation rate; Pyrite; Sulfur isotope

Abstract: ► Mass accumulation rates (MAR) in the abyssal Black Sea were 61 to 76 g m⁻² yr⁻¹. ► These values point to increasing MARs for the past century. ► In the cores with turbidites, we used Chernobyl-derived Cs-137 to compute MAR. ► In turbidite-impacted cores, MAR can be as high as 5230 g m⁻² yr⁻¹. ► Fast deposition was reflected in the pyrite sulfur isotopic ratios as well.

URL: http://www.sciencedirect.com/science/article/pii/S096706371200088X