タグ「(radiation) deposition」
Title: The role of soil erosion and fluvial processes in the post-fallout redistribution of Chernobyl-derived caesium-137: a case study of the Lapki catchment, Central Russia
Author: A.V Panin, D.E Walling, V.N Golosov
Reference: Geomorphology, Volume 40, Issues 3–4, October 2001, Pages 185-204
DOI: http://dx.doi.org/10.1016/S0169-555X(01)00043-5
Keywords: Chernobyl; Caesium-137; Redistribution; Fluvial processes; Sediment; Soil erosion; Deposition
Abstract: The central area of the Russian Plain received substantial amounts Cs-137 fallout as a result of the Chernobyl accident in 1986, with inventories exceeding 40 kBq m−2 in many of the areas close to Chernobyl. Concern over the longer-term fate of this contamination has focused attention on the need to predict the post-fallout redistribution of the radiocaesium and, thus, future changes in the spatial distribution of contamination in the landscape. Since radiocaesium reaching the land surface as fallout is rapidly and strongly adsorbed by soil and sediment particles, any attempt to predict its post-fallout redistribution must focus on erosion and sediment delivery processes and must rely heavily on a knowledge of the geomorphological processes involved. This paper reports a detailed investigation of post-fallout Cs-137 redistribution in the 2.18-km2 Lapki catchment in the Middle-Russian Upland, which has required consideration of soil erosion processes, sediment delivery pathways, sediment delivery ratios and sediment sinks. The time elapsed since the Chernobyl accident is currently insufficient to result in significant reduction of Cs-137 inventories in eroding areas, but areas of deposition on both the lower slopes and on the balka sides and bottoms are already marked by significant increases in Cs-137 inventories. The results obtained emphasise that any attempt to develop meaningful predictions of the longer-term redistribution of Chernobyl-derived Cs-137 fallout within the Russian Plain must be based on a sound and detailed understanding of the linkage between the slopes and the balka systems and the fate of sediment entering the balka systems.
URL: http://www.sciencedirect.com/science/article/pii/S0169555X01000435
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
Title: Determination of 99Tc deposited on the ground within the 30-km zone around the chernobyl reactor and estimation of 99Tc released into atmosphere by the accident
Author: S. Uchida, K. Tagami, W. Rühm, E. Wirth
Reference: Chemosphere, Volume 39, Issue 15, December 1999, Pages 2757-2766
DOI: http://dx.doi.org/10.1016/S0045-6535(99)00210-6
Keywords: Technetium-99; Chernobyl accident; Forest soil; Deposition; Cesium-137; Migration
Abstract: Technetium-99 was determined in samples from the 30-km zone around the Chernobyl reactor. Concentrations of 99Tc in soil samples taken from three forest sites ranged from 1.1 to 14.1 Bq kg−1 dry weight for the organic soil layers, and from 0.13 to 0.83 Bq kg−1 dry weight for the mineral soil layers. In particular, for the organic layers, the measured 99Tc concentrations were one or two orders of magnitude higher than those due to global fallout 99Tc. The 99Tc depositions (Bq m−2), based on the sum of the depositions measured in organic and mineral layers, ranged from 130 Bq m−2 within the 10-km zone to about 20 Bq m−2 close to the border of the 30-km zone. Taking the corresponding measured 137Cs depositions into account, it was found that the activity ratio of ranged from 6 × 10−5 to 1.2 × 10−4. It was estimated that about 970 GBq of 99Tc had been released by the Chernobyl accident. This figure corresponded to 2%–3% of the total 99Tc inventory in the core.
URL: http://www.sciencedirect.com/science/article/pii/S0045653599002106
Title: 129I in lakes of the Chernobyl fallout region and its environmental implications
Author: N Buraglio, A Aldahan, G Possnert
Reference: Applied Radiation and Isotopes, Volume 55, Issue 5, November 2001, Pages 715-720
DOI: http://dx.doi.org/10.1016/S0969-8043(00)00353-5
Keywords: Accelerator mass spectrometry (AMS); Iodine; Deposition; Chernobyl; Reprocessing facilities
Abstract: We present seasonal results of 129I in fresh-water lakes located in central Sweden, an area over which the amount of fallout deposition from the Chernobyl accident varied significantly (2–120 kBq/m2 for 137Cs). 129I concentrations in the lakes ranged from 2.1 to 15.0×108 atoms per liter and did not show elevated concentration in lakes located in regions of high Chernobyl fallout. Apparently, the studied region is strongly influenced by 129I releases from the reprocessing facilities through precipitation. Desorption or resuspension of 129I from soils and sediments does not seem to be an active process to increase the concentration of 129I in the lakes.
URL: http://www.sciencedirect.com/science/article/pii/S0969804300003535
Title: Simulation of the chernobyl radioactive cloud over Europe using the eurad model
Author: H. Hass, M. Memmesheimer, H. Geiβ, H.J. Jakobs, M. Laube, A. Ebel
Reference: Atmospheric Environment. Part A. General Topics, Volume 24, Issue 3, 1990, Pages 673-692
DOI: http://dx.doi.org/10.1016/0960-1686(90)90022-F
Keywords: Forecast; accidental release; Chernobyl; long-range transport; deposition; radionuclides
Abstract: The opean cid eposition Model (EURAD) is used to investigate the long-range transport (LRT) and deposition of radioactive material in Europe during the first week after the Chernobyl accident. Emphasis is laid on using the model system in a forecast mode as possibly would be done shortly after such an event. Thus, meteorological fields are predicted with the PSU/NCAR mososcale model MM4.The multilayer Eulerian model CTM ( hemistry ransport ) is applied to compute transport and deposition of Cs-137 and I-131 using the predicted meteorological fields. However, the accident scenario was estimated using published data. The model results and performance are discussed by comparison with observations. It is demonstrated that the model can reproduce certain observed characteristics of the radioactive cloud, i.e. trends in surface air concentrations, arrival times and wet deposition patterns. This leads to the suggestion that the predictive capability of the EURAD-system has a relatively high level considering the fact that several simple approaches were used.
URL: http://www.sciencedirect.com/science/article/pii/096016869090022F
Title: Geographical mapping and associated fractal analysis of the long-lived Chernobyl fallout radionuclides in Greece
Author: N.P Petropoulos, M.J Anagnostakis, E.P Hinis, S.E Simopoulos
Reference: Journal of Environmental Radioactivity, Volume 53, Issue 1, 2001, Pages 59-66
DOI: http://dx.doi.org/10.1016/S0265-931X(00)00111-9
Keywords: Chernobyl fallout; Mapping; Fractal analysis; Deposition pattern
Abstract: Immediately after the Chernobyl accident, a soil sampling programme was undertaken in order to detect and quantitatively analyse the long-lived radionuclides in the Chernobyl fallout. Soil samples (1242 in number) of 1 cm thick surface soil were collected in Greece during the period from May–November 1986. The samples were counted and analysed using Ge detector set-ups. The fallout data have already been analysed, mapped and published. In an attempt to improve this analysis and also to extend it to other fallout radionuclides, an in-house unix-based data base/geographical information system (DBGIS) was developed. Multifractal analyses of the deposition patterns have also been performed. In the present work, an analysis of the results of the deposition of [, , , , , , , , ]and are presented together with relevant fractal analysis and three characteristic contour maps. The maximum detected values of the above-mentioned radionuclides were 149.5±0.1, 76.1±0.1, 32.9±0.2, 46±2, 4.56±0.02, 7.98±0.02, 79.1±0.4, 337±2, 20.1±0.2 and 3.02±0.02 kBq m−2, respectively. Furthermore, a statistical technique to compare contour maps was introduced and applied to explain the differences which appeared in the maps of the above-mentioned radionuclides.
URL: http://www.sciencedirect.com/science/article/pii/S0265931X00001119
