Estimation of doses received in a dry-contaminated residential area in the Bryansk region, Russia, since the Chernobyl accident

Title: Estimation of doses received in a dry-contaminated residential area in the Bryansk region, Russia, since the Chernobyl accident

Author: K.G. Andersson, J. Roed

Reference: Journal of Environmental Radioactivity, Volume 85, Issues 2–3, 2006, Pages 228-240

DOI: http://dx.doi.org/10.1016/j.jenvrad.2004.08.019

Keywords: Radiation dose; Radiocaesium; Urban; Chernobyl; Preparedness; Dry deposition

Abstract: In nuclear preparedness, an essential requirement is the ability to adequately predict the likely consequences of a major accident situation. In this context it is very important to evaluate which contributions to dose are important, and which are not likely to have significance. As an example of this type of evaluation, a case study has been conducted to estimate the doses received over the first 17 years after the Chernobyl accident in a dry-contaminated residential area in the Bryansk region in Russia. Methodologies for estimation of doses received through nine different pathways, including contamination of streets, roofs, exterior walls, and landscape, are established, and best estimates are given for each of the dose contributions. Generally, contaminated soil areas were estimated to have given the highest dose contribution, but a number of other contributions to dose, e.g., from contaminated roofs and inhalation of contaminants during the passage of the contaminated plume, were of the same order of magnitude.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X05002183

Gamma-dose rates from terrestrial and Chernobyl radionuclides inside and outside settlements in the Bryansk Region, Russia in 1996–2003

Title: Gamma-dose rates from terrestrial and Chernobyl radionuclides inside and outside settlements in the Bryansk Region, Russia in 1996–2003

Author: Valery Ramzaev, Hidenori Yonehara, Ralf Hille, Anatoly Barkovsky, Arkady Mishine, Sarat Kumar Sahoo, Katsumi Kurotaki, Masafumi Uchiyama

Reference: Journal of Environmental Radioactivity, Volume 85, Issues 2–3, 2006, Pages 205-227

DOI: http://dx.doi.org/10.1016/j.jenvrad.2004.04.014

Keywords: Chernobyl accident; Cesium; Terrestrial radionuclides; Gamma-dose rates; Effective doses

Abstract: In order to estimate current external gamma doses to the population of the Russian territories contaminated as a result of the Chernobyl accident, absorbed gamma-dose rates in air (DR) were determined at typical urban and suburban locations. The study was performed in the western districts of the Bryansk Region within the areas of 30 settlements (28 villages and 2 towns) with the initial levels of ¹³⁷Cs deposition ranging from 13 to 4340 kBq m⁻². In the towns, the living areas considered were private one-story wooden and stone houses. DR values were derived from in situ measurements performed with the help of gamma-dosimeters and gamma-spectrometers as well as from the results of soil samples analysis. In the areas under study, the values of DR from terrestrial radionuclides were 25 ± 6, 24 ± 5, 50 ± 10, 32 ± 6, 54 ± 11, 24 ± 8, 20 ± 6, 25 ± 8, and 18 ± 5 nGy h⁻¹ at locations of kitchen gardens, dirt surfaces, asphalt surfaces, wooden houses, stone houses, grasslands inside settlement, grasslands outside settlement, ploughed fields, and forests, respectively. In 1996–2001, mean normalized (per MBq m⁻² of ¹³⁷Cs current inventory in soil) values of DR from ¹³⁷Cs were 0.41 ± 0.07, 0.26 ± 0.13, 0.15 ± 0.07, 0.10 ± 0.05, 0.05 ± 0.04, 0.48 ± 0.12, 1.04 ± 0.22, 0.37 ± 0.07, and 1.15 ± 0.19 μGy h⁻¹ at the locations of kitchen gardens, dirt surfaces, asphalt surfaces, wooden houses, stone houses, grasslands inside settlement, grasslands outside settlement, ploughed fields, and forests, respectively. The radiometric data from this work and the values of occupancy factors determined for the Russian population by others were used for the assessments of annual effective doses to three selected groups of rural population. The normalized (per MBq m⁻²¹³⁷Cs current ground deposition) external effective doses to adults from ¹³⁷Cs ranged from 0.66 to 2.27 mSv y⁻¹ in the years 1996–2001, in accordance with professional activities and structures of living areas. For the areas under study, the average external effective doses from ¹³⁷Cs were estimated to be in the range of 0.39–1.34 mSv y⁻¹ in 2001. The average external effective doses from natural radionuclides appeared to be lower than those from the Chernobyl fallout ranging from 0.15 to 0.27 mSv y⁻¹.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X05002171

Validation of 131I ecological transfer models and thyroid dose assessments using Chernobyl fallout data from the Plavsk district, Russia

Title: Validation of 131I ecological transfer models and thyroid dose assessments using Chernobyl fallout data from the Plavsk district, Russia

Author: I. Zvonova, P. Krajewski, V. Berkovsky, M. Ammann, C. Duffa, V. Filistovic, T. Homma, B. Kanyar, T. Nedveckaite, S.L. Simon, O. Vlasov, D. Webbe-Wood

Reference: Journal of Environmental Radioactivity, Volume 101, Issue 1, January 2010, Pages 8-15

DOI: http://dx.doi.org/10.1016/j.jenvrad.2009.08.005

Keywords: Chernobyl accident; Iodine-131; Environment modeling; Models validation; Population; Thyroid dose

Abstract: Within the project “Environmental Modelling for Radiation Safety” (EMRAS) organized by the IAEA in 2003 experimental data of ¹³¹I measurements following the Chernobyl accident in the Plavsk district of Tula region, Russia were used to validate the calculations of some radioecological transfer models. Nine models participated in the inter-comparison. Levels of ¹³⁷Cs soil contamination in all the settlements and ¹³¹I/¹³⁷Cs isotopic ratios in the depositions in some locations were used as the main input information. 370 measurements of ¹³¹I content in thyroid of townspeople and villagers, and 90 measurements of ¹³¹I concentration in milk were used for validation of the model predictions.A remarkable improvement in models performance comparing with previous inter-comparison exercise was demonstrated. Predictions of the various models were within a factor of three relative to the observations, discrepancies between the estimates of average doses to thyroid produced by most participant not exceeded a factor of ten.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X09001751

Important factors governing exposure of the population and countermeasure application in rural settlements of the Russian Federation in the long term after the Chernobyl accident

Title: Important factors governing exposure of the population and countermeasure application in rural settlements of the Russian Federation in the long term after the Chernobyl accident

Author: S Fesenko, P Jacob, R Alexakhin, N.I Sanzharova, A Panov, G Fesenko, L Cecille

Reference: Journal of Environmental Radioactivity, Volume 56, Issues 1–2, 2001, Pages 77-98

DOI: http://dx.doi.org/10.1016/S0265-931X(01)00048-0

Keywords: Countermeasures; Chernobyl; Rural settlements; Remediation; Russia

Abstract: Rural settlements located in areas of the Russian Federation contaminated after the Chernobyl accident and exceeding an annual dose of 1 mSv a⁻¹ have been classified according to ¹³⁷Cs contamination density, internal dose and the neighbourhood of forests. It has been shown that, with the exception of the most contaminated areas, the internal doses decreased in accordance with a decline in ¹³⁷Cs availability for plant root uptake. An inverse tendency was observed in areas with ¹³⁷Cs contamination above 555 kBq m⁻² which can be explained by a reduction or even termination of countermeasure application and by an increasing consumption of forest products in areas where restrictive countermeasures are still implemented. Twenty-seven settlements have been studied to estimate the effectiveness of countermeasures applied previously and to identify the most important factors governing the radiation exposure to the population and its change with time. It has been shown that the effectiveness of countermeasures which resulted in a decrease of up to 40% of doses has a tendency to decline in the long term.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X01000480

Model testing using data on 137Cs from Chernobyl fallout in the Iput River catchment area of Russia

Title: Model testing using data on ¹³⁷Cs from Chernobyl fallout in the Iput River catchment area of Russia

Author: Thiessen, K.M.; Sazykina, T.G.; Apostoaei, A.I.; Balonov, M.I.; Crawford, J.; Domel, R.; Fesenko, S.V.; Filistovic, V.; Galeriu, D.; Homma, T.; Kanyar, B.; Krajewski, P.; Kryshev, A.I.; Kryshev, I.I.; Nedveckaite, T.; Ould-Dada, Z.; Sanzharova, N.I.; Robinson, C.; Sjoblom, K.-L.

Reference: Journal of Environmental Radioactivity, 2005, vol.84, no.2, pp. 225-44

doi: 10.1016/j.jenvrad.2004.10.016

Keywords: Cesium-137; Model testing; Dose reconstruction; Chernobyl

Abstract: Data collected for 10 years following the Chernobyl accident in 1986 have provided a unique opportunity to test the reliability of computer models for contamination of terrestrial and aquatic environments. The Iput River scenario was used by the Dose Reconstruction Working Group of the BIOMASS (Biosphere Modelling and Assessment Methods) programme. The test area was one of the most highly contaminated areas in Russia following the accident, with an average contamination density of ¹³⁷Cs of 800,000 Bq m⁻² and localized contamination up to 1,500,000 Bq m⁻², and a variety of countermeasures that were implemented in the test area had to be considered in the modelling exercise. Difficulties encountered during the exercise included averaging of data to account for uneven contamination of the test area, simulating the downward migration and changes in bioavailability of ¹³⁷Cs in soil, and modelling the effectiveness of countermeasures. The accuracy of model predictions is dependent at least in part on the experience and judgment of the participant in interpretation of input information, selection of parameter values, and treatment of uncertainties.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X05001499

Mobility of radionuclides in undisturbed and cultivated soils in Ukraine, Belarus and Russia six years after the Chernobyl fallout

• Title: Mobility of radionuclides in undisturbed and cultivated soils in Ukraine, Belarus and Russia six years after the Chernobyl fallout

Author: Askbrant, S. / Melin, J. / Sandalls, J. / Rauret, G. / Vallejo, R. / Hinton, T. / Cremers, A. / (…) / Alexakhin, R.M.

Reference: Journal of Environmental Radioactivity, 31 (3), p.287-312, Jan 1996                 

doi: 10.1016/0265-931X(95)00054-E

Keywords:

Abstract: Six years after the accident at the Chernobyl Nuclear Power Plant, the behaviour of radionuclides in soils in rural areas of Ukraine, Belarus and Russia has been studied. Measurements were made to determine the total radioactive contamination, the fuel particle contribution, and the distribution and extractability of the radionuclides ¹³⁷Cs and ⁹⁰Sr. Inside the 30 km restriction zone around the plant, particles of highly irradiated fuel accounted for most of the radioactive contamination.

URL: http://www.sciencedirect.com/science/article/pii/0265931X9500054E