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Impact of nitrogen on accumulation of Cs by Calla palustris
Benediktová, Eva ; Komínková, Dana (advisor) ; Petr, Petr (referee)
This work deals with the evaluation of Calla palustris utilization for phytoremediation and clarifying how nitrogen influences the uptake of cesium from aqueous solution. The plants were subjected to nitrogen exposure, which consisted of five different concentrations of NH4+ and NO3- and 0.5 mM CsCl, for eight days. The greatest amount of cesium (13.5%) accumulated the plants without the addition of nitrogen, the smallest amount accumulated plants with concentrations of 6: 3 (3.9%), 8: 4 (3.6%) and 10: 5 NH4NO3: NH4Cl (3.5%). Calla has proved to be suitable for phytoremediation, however with the need for longer exposure. Besides these main hypotheses it has been moreover shown that the state of plants affected the uptake of cesium and that nitrogen influenced the condition of the plant. Further it has not been observed noticeable difference in uptake of cesium in roots and stems with leaves.
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Impact of potassium on accumulation of Cs by Calla palustris
Poláková, Monika ; Komínková, Dana (advisor) ; Petr, Petr (referee)
Environmental contamination with radionuclides is a growing problem in the world. Phytoremediation seems to be a suitable method for the removal of radionuclides from the environment. The aim of this study was to determine the impact of potassium on accumulation of stable isotope 133Cs and evaluate the suitability of plant species Calla palustris for phytoremediation. Plants were grown in a water solution in a greenhouse and after one week of pre-cultivation were exposed to stable isotope 133Cs (0,5 mM CsCl). Potassium was added in five various concentrations in the form of K2SO4. The level of cesium in plants was measured after 8 days of exposition. Plants without added potassium absorbed the most cesium (11,52 %). Plants with the highest concentration of added K2SO4 10 mM (3,45 %), 5 mM (3,62 %), 2 mM (5,57 %) absorbed the least. Higher 133Cs accumulation was measured in the plant roots than in the above- ground plant parts. Total uptake of cesium by Calla palustris suggests the possibility to use Calla palustris for phytoremediation.
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Knowledge of population in a selected region about the Chernobyl Nuclear Power Plant accident consequences
PRAŽÁK, Marek
The Chernobyl nuclear disaster of April 26, 1986 is the worst nuclear accident in the history of mankind. An experiment conducted in the 4th reactor resulted in its explosion and a huge amount of radionuclides escaped into the environment in the course of the subsequent fire. The greater part of Europe was contaminated by radioactive fallout, including the former Czechoslovak Socialist Republic. From a health point of view, the most harmful radioactive substances causing radioactive contamination were caesium 137Cs and iodine 131I. The then government did not provide objective and true information to the citizens and the media depicted the disaster as an insignificant incident. I set the following goals of my thesis: a) to develop an overview of immediate and especially long-term consequences of the accident; b) to analyse the knowledge of the population of the South Bohemian Region of the consequences of the Chernobyl disaster depending on the age of respondents. For fulfilling the set goals, I set myself the following hypotheses: H1) the theoretical division of the population's knowledge will be normal; H2) the knowledge of persons over 45 years of age will statistically be significantly higher than that of younger people. I handled the given theme using available specialized literature, Internet sources and publications published by relevant institutions. In the introductory part I describe the construction of the power plant, basic technical parameters of the reactor used and the course and causes of the actual accident. The next section is focused on the consequences of the accident in individual time periods immediately, after 10 years and after 20 years. I devote myself both to influences on human lives and health and to environmental, social, economic and psychological consequences. Furthermore,I describe the situation in former Czechoslovakia and the way of informing the population by the then government. The last section of the theoretical part is dedicated to the present situation in the Chernobyl region and at the power plant itself. While compiling the research part of the thesis, I gathered data among the inhabitants of the South Bohemian Region through questionnaire investigation. I addressed a total of 280 respondents, of which 140 were under 45 years of age and 140 were over 45 years of age. The questionnaire contained 15 questions concerning basic, not professional knowledge in this area. For the purposes of my questionnaire investigation, I divided the South Bohemian Region into districts. The selection of individual towns within the framework of the questionnaire investigation was carried out at random, by drawing lots. 280 questionnaires were completed in all, of which 140 questionnaires were completed by respondents under 45 and 140 questionnaires were completed by respondents over 45. By drawing lots, I selected 100 questionnaires out of these completed questionnaires, each age group being included. The test of the set hypotheses and statistical evaluation are carried out using descriptive and mathematical statistics. I carried out statistical evaluation by testing normality, using X2-good agreement test. I mutually compared the knowledge of the groups monitored by testing using a two-sample t-test, based on the estimate of empirical parameters from each group. Based on statistical investigation I came to the conclusion that the division of the population's theoretical knowledge was normal, which confirms the first hypothesis. The results of the investigation also unambiguously confirmed the fact that the knowledge of the population over 45 years of age was statistically significantly higher than the knowledge of the younger group of respondents. As far as total evaluation is concerned, the average value of correct answers in case of the older group of respondents reached 71%, while the younger group showed just 44% of correct answers, which confirms the second se hypothesis.
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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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Content of cesium-137 in forest ecosystem in selected locations
SEBEROVÁ, Pavlína
The human and the whole environment are irradiated from the different sources (natural or artificial). The natural sources of radiation are cosmic and sun rays or the natural radiation of the Earth. The artificial sources mean cyclotrons, X-rays, particle accelerators, nuclear reactors and others. Natural cesium is located very rarely on Earth, but it has many artificial isotopes (for example Cs-137 and Cs-134). The Cs-137 is an artificial isotope produced by human. The first source of the Cs-137 became the nuclear tests and attacks used in the World War Two. In the 1960s (related a study of nuclear weapons) there were found out storing of Cs-137 in the surface soil layers. Even the peaceful use of the nuclear energy could cause the nuclear crash accompanied by a leakage of radioactive substances. The most tragic crash was an explosion of the nuclear power station Chernobyl in Ukraine. That crash contaminated the whole Ukraine and close states, but also Scandinavia. The spread of the Cs-137 depended on the rainfall and the air flow. Human has been affected by the radioactive elements even after the long time since the crash. Forest ecosystem seems to be the place with the largest amount of Cs-137 located. The Cs-137 may get into the human body though food; it has a very long half-time (30ys), it is stored in the top soil layers and through the root system of plants gets into the plants or mushrooms. The aim of this thesis is to determine and compare the content of the Cs-137 in the selected commodities in the forest ecosystem of Šumava using semiconductor gamma spectrometry. The research question was specified: Is the content of the Cs-137 in the selected commodities of the Šumava forest area significantly different? Based on an analysis of literature and consultation with the State Office for Nuclear Safety there were chosen areas, where was the highest fallout of radioactive elements. Therefore I sampled the area called Kvilda, Zadov and Churáňov. Further locations with the commodities of the forest ecosystem are Bavorov, Svinětice and Baranaviči. There are samples of soil, moss, spruce bark, cones and lichen. Not all commodities could be collected in all locations because there were picked in a small area and not all commodities occurred there. To determine the mass activity of the Cs-137 samples I used a semiconductor gamma spectrometry. The obtained spectra were evaluated through software GAMAT. The range of the values of mass activity of the Cs-137 in all samples is between 3-700 Bq.kg-1. The highest activity was measured in soil, where values reached up to 700 Bq.kg-1. High activity was also measured in moss in Kvilda, 513 Bq.kg-1. Samples of spruce bark, cones and lichens have low values activity. It was not reached out the value of 300 Bq.kg-1. Answer to the research question is that contamination of Sumava Cs-137 in selected commodities forest ecosystem is significantly uneven.
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Independent monitoring of Nuclear power plant Temelin environs by Regional centrum of SONS České Budějovice. Project of independent monitoring NPPTE in the case of Emergency incident.
ZEMAN, Karel
The State Office for Nuclear Safety (SONS) and the National Radiation Protection Institute (NRPI) are involved in independent monitoring of surrounding areas of nuclear power plants (NPPs), in accordance with the Czech legislative requirements (Decree No. 319/2002 Coll. on radiation monitoring network (RMS), as amended by Decree No. 27/2006 Coll.). The monitoring includes surveillance of environmental samples, in which radionuclides can be detected in case of emergency event, i.e. radioactivity release from the NPP. Another part of the monitoring is measurement of photon dose equivalent, continuously in the air (early detection network - SVZ) or using thermoluminescent dosimeters (TLD) placed in SONS monitoring points in the NPP vicinity. Environmental sampling and evaluation of photon dose equivalent in the air is carried out in regular intervals. The 137Cs and 131I activity is measured by gamaspectrometry method used with Gamat evaluation program, according to SONS internal procedure (VDMI). Tritium activity in surface water is measured by liquid scintillation spectrometer Beta TriCarb made by Canberra Packard Company, according to methodology CSN ISO 9698 (757635). Evaluation of dose equivalent rate is carried out continuously by LB 6360 proportional probe and LB 6500-3 Geiger-Muller tube located in RC Building in Ceske Budejovice. TLD evaluation is carried out by NRPI laboratory in Prague and the results are sent to SONS RC Ceske Budejovice. Goal of this work is to provide a set of results of the independent monitoring in surrounding areas of Temelin NPP (ETE) carried out between 1999 and 2009, by determination of volume, mass or surface activity of environmental samples (137Cs and 131I) and spot samples of water (3H) taken from SONS monitoring points near ETE . The set of such results should provide a baseline reference values for normal (pre-accident) situations. Additionally, based on the long term of the ETE surrounding surveillance, it can be shown that the ETE operation represents no threat to the health of the critical population group, and that the radiation situation in the ETE surrounding is stable. It can be also shown that the ETE operator meets requirements and conditions of authorized limits for discharging radionuclides into the environment. Procedures and method of independent environmental monitoring in the ETE surrounding during emergency events can be proposed on the basis of many years of experience with proven methodologies, experience with sampling locations, staffing and organization of measurement.
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