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Residual Contamination of Soils with Artificial Radionuclides Sr-90 and Cs-137
Kadlecová, Tereza ; Sedlářová, Barbora (advisor) ; Bruthans, Jiří (referee)
The review part of this bachelor thesis deals with sources of artificial radionuclides strontium- 90 and caesium-137, which are released into the environment mainly due to nuclear weapons tests and nuclear accidents. The most extensive contamination of the Czech Republic was caused by the Chernobyl accident in 1986. The transport of strontium-90 and caesium-137 through the environment is summarised, with emphasis on soil. In the experimental part of the work, the residual contamination of arable and meadow soil with these radionuclides was evaluated in the Veltrusy locality in relation to hydropedological properties. This site was chosen in connection with the project "Innovative methods for the detection of ultra-low concentrations of radionuclides to assess the vulnerability of drinking water sources in the event of a nuclear accident", which was carried out within the T. G. Masaryk Water Research Institute. It was found that contamination varies depending on land use, such as cultivated and uncultivated land. Strontium-90 was not measurable at either site, whereas caesium-137 was detectable at both of them. Most of the caesium-137 in the grassland soil was measured in the near-surface layer of the soil, whereas in the arable soil it was evenly distributed throughout the profile. The mobility of...
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Aktuální stav důsledků havárie černobylského jaderného reaktoru z agroekologického pohledu se zaměřením na kontaminaci zemědělské půdy
Ondračka, Tomáš
Bachelor thesis deals with the current agricultural soil contamination with radionuclides as a result of nuclear reactor accident at Chernobyl in 1986. The work is processed as a review of the literature on the issue. The thesis presents the physico-chemical properties of selected anthropogenic radionuclides. Due to the physical half-life work continues to address only radionuclides with long half-life, their transfer in the environment, focusing on the interaction of these radionuclides in the soil system. At the conclusion of this work a list of other important soil contaminants and their comparison with radio-contaminants is submitted.
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Agroekologické důsledky havárie reaktorů v japonské jaderné elektrárně Fukušima I. se zaměřením na vodní ekosystémy
Krejčí, Michal
This thesis deals with agroecological consequences of the Fukushima Daiichi power plant accident and it focuses on aquatic environment. It includes short history of radioactive elements in energetics. It also includes properties of the most important fission products. The thesis describes the accident of the power plant, fission products that were released into the environment through atmospheric release and direct discharges of contaminated water, measuring and monitoring of the contaminants, their movement and accumulation in river and marine ecosystems. The thesis focuses on radioisotope 137Cs, its accumulation in river and ocean sediments, sea algae and aquatic organisms. There is a special chapter about accumulation of 137Cs in fish which are a key component in aquatic ecosystems and also they are often consumed in Japan.
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Radiocesium v zemědělsky neobdělávaných půdách
Kubějová, Michaela
The diploma thesis Radiocaesium in agricultural uncultivated soils is focused on creation literary review, collection soil samples and then preparation of samples for gamaspectrometric analysis to determine content of the radionuclide (137Cs). In the first part of literature review radiocaesium and its sources in the environment are characterised. Radiocaesium transport in atmosphere, the 137Cs deposition on soil and its influence on human is included. In the next part, soil parameters, behaviour of radiocaesium in soil, following countermeasures, differences between soils in agroecosystems and agricultural uncultivated soils, contamination of soils with radiocaesium in Czech Republic are described. Materials, methodology and description of chosen locations are followed. The main part of the thesis is focused on determination of radiocaesium content in uncultivated soils. In 2013, soil samples (57 samples of 5-cm-top A organic profiles and 57 samples of deeper B mineral profiles from 5-12-cm of depth) were taken from four selected locations: Valašské Meziříčí-Juřinka, Velké Karlovice, Loukov, Prostřední Bečva. Soil samples were always collected in three specific areas: meadow, deciduous forest (mixed forest) and coniferous forest. The lowest values of 137Cs activity in soils were observed in Juřinka (average value in profiles A 16.9 +- 4.29 Bq.kg-1 and B 11.6 +- 2.53 Bq.kg-1), then in Loukov (average value in profiles A 38.8 +- 30.22 Bq.kg-1 and B 18.6 +- 12.60 Bq.kg-1). The highest values 137Cs in Velké Karlovice (in profiles A 64.7 +- 44.11 Bq.kg-1 and B 30.1 +- 21.50 Bq.kg-1), lower values in Prostřední Bečva (in profiles A 46.6 +- 30.01 Bq.kg-1 and B 24.9 +- 28.50 Bq.kg-1) were measured. Significant differences between 137Cs activity in top A soil profile and deeper B profile in all four locations were found (T-test, P less then 0.05). In all locations, the highest average values radiocaesium activities were observed in coniferous forest (average values in profiles A 65.7 +- 41.91 Bq.kg-1 and B 35.03 +- 28.94 Bq.kg-1), then in deciduous forest (average values in profiles A 33.8 +- 17.27 Bq.kg-1 and B 20.1 +- 7.51 Bq.kg-1) and the lowest in meadows (average values in profiles A 14.9 +- 4.53 Bq.kg-1 and B 10.7 +- 3.63 Bq.kg-1), (P less then 0.05). The 137Cs activities in soil profiles were converted from the radiocaesium activity concentration (Bq kg-1) to the 137Cs depositional density (kBq m-2), and the densities ranged from 0.93 to 12.94 kBq m-2. Results were processed to tables, graphs and map. In the closing part of thesis, our results were discussed and compared with published data and ecological importance of radiocaesium activity in agricultural uncultivated soils was also assessed.
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Determination of volume activity of gamma nuclide in environmental samples and assessment of influence of NPP Temelin on actual measured activity
DAVIDOVÁ, Lenka
In this thesis I target the assesment of a volume activity of gamma ray nuclides in the environment and the examination of the operation the Nuclear Power Station (NPS) Temelín in term of emitting the gamma ray nuclides and their environmental impact. There were collected data of several sorts of environmental samples for statistical analysis. The activity of gamma ray nuclides released by nuclear power plants to the environment after its initiation was compared to the activity of gamma ray nuclides contained it the environment before the initiation of the NPS. It was chosen five exemplary samples - , aerosoles, sediments, milk, soil and surface moisture, which have been scanning in years 1995 and 2005. In these samples, that have sufficient amount of data (sorts of milk, aerosoles and surface moisture) so the statistical analysis was relevant, it was proved, by the non-parametrical Mann-Whitney statistical testing, that there were no statistical difference between the data before and after the initiation of the NPS. The environmental impact wasn´t demonstrated. In these samples, that haven´t sufficient amount of data (sediments and soil), they were also tested (parametrical t. test) and it was proved that there were no statistical difference between the data before and after the initiation of the NPS. Because of very low quality of the testing, we have to use the box plot to ascertain the influence of NPS. In these plots the environmental impact wasn´t demonstrated as well.
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