|
|
Determination of radionuclides in water and sediments
Bílek, Jiří ; Holubová, Zuzana (referee) ; Komendová, Renata (advisor)
This thesis has been prepared for DIAMO, Branch GEAM Dolní Rožínka. Literature research includes a description of the ionizing radiation, natural radionuclides, mining of uranium ore and mineral deposits; Běstvina and Licoměřice. The experimental part includes sampling, analysis and evaluation of the content of selected radionuclides in the two selected locations. The content of uranium and radium in sludge from mine water treatment plant is determined annually by an external laboratory, using of semiconductor gamma-spectrometric analysis (GSA). Determination of both radionuclides in waters in these areas is carried out in the Centre of testing laboratories (SZLAB) in Dolní Rožínka. Uranium and radium activity is below the detection limit. Sludges from Běstvina, according to the results of external laboratories, routinely show activity of both radionuclides. But activity in the waters from this locality is below the detection limit. The goal of this diploma thesis is to verify the radionuclide content in sludge from CDV Běstvina by another method. As a comparative method was chosen determination of uranium using the UV-VIS spectrophotometry with separation on silicagel. Location Licoměřice was chosen as a reference. Like a supplementary method for determining the concentration of uranium was chosen ICP-MS. For the determination of the radium was chosen radiochemical method scintillator ZnS (Ag).
|
|
| |
|
|
Radioactive wastes and the release of radioactive substances into the environment (learning program)
NOVÁK, Jan
This bachelor thesis, "Radioactive waste and the release of radioactive substances into the environment", is concerned (among others) with nuclear fuel and the biological effects of ionizing radiation. First, it briefly describes the history of this branch in the Czech Republic. Then the work is focused on the effects of ionizing radiation, divided into deterministic and stochastic effects. The work also contains a list of legislative norms regarding the handling of radioactive waste in the Czech Republic and the European Union. Protection of the environment and health against hazardous radioactive waste is at present regulated by several guidelines. The primary objective of this work was to compile a comprehensive basis for presentation to university students on the subject of radioactive waste and its impact on the environment. The concluding discussion presents the author's views on another possible application of e-learning in dealing with this branch of study at the University of South Bohemia.
|
|
|
The distribution of radioactive stroncium in organism
PAULŮ, Zuzana
The topic of my bachelor thesis is the distribution of radioactive strontium in organism. The thesis is divided into three main parts. In the first part I describe general problems of radioactive strontium, talk about possible ways of entrance of this radionuclide into organism and discuss resulting health hazards. In the second part I mentioned three case studies dealing with contamination by radioactive strontium. The first case study describes the long term contamination by 90Sr in the Techa river population. The second one is the study of a group of volunteers who received 85Sr and subsequently the excretion, elimination and retention of this radionuclide in the organism of the volunteers were observed. The last case study describes the influence of the external radiation on distribution of the radioactive strontium in the organism of rats. The third part of my graduation thesis contains the discussion on the problem of distribution of radioactive strontium in the organism of mammals. The aim of my bachelors thesis was to make analysis of the distribution of radioactive strontium in organism according to different ways of its entrance into the organism. My hypothesis was that the degree of damage to the organism does not depend on the way of entrance of this radioactive strontium into the organism. The hypothesis was rejected after I analysed and compared all avaliable data.
|
|
|
The most considerable of radionuclides at the accident of the nuclear power station, the experience of Chernobyl
HORÁKOVÁ, Magdaléna
At the nuclear power plant accident, the radionuclides with very short half-life come to enviroment, they decay the period from several second to several months. On the other sides come to enviroment radionuclides with long half-life. Their radionuclides occur in surrounding of the power plant for hundreds of years before they decay totally. Immediately after a nuclear power plant accident, radioiodine represents the most severe health hazard for population. Because it is a radionuclide with short half-life, it causes the danger during first months after the accident. Its health hazard lies in the fact, that it gets to food chains and irradiates a man, who consumed contaminated water and food. Radiocaesium and radiostrontiom are the next important radionuclides. They have long half-lifes, it means that will decay after hundred years after the accident and they endanger population a long time after the accident yet.
|
|
| |
|
|
Effectiveness evaluation of countermeasures adopted after the Chernobyl accident
ROTREKLOVÁ, Tereza
The utilisation of nuclear energy entails, like any other human activity, risk of occurrence of accidents and emergencies. On Saturday 26th April 1986 early morning in the fourth block of the Chernobyl nuclear power plant in Ukraine occurred the biggest industrial accident in the peace usage of nuclear energy. It led to a vast leakage of radioactive debris to the wide surrounding area. An accident of such extent has never been thought possible before and it has surprised national authorities responsible for emergency preparedness practically in all counties operating nuclear power plants. It was crucial to prepare and introduce many countermeasures to restrict exposure of persons and environment to radiation. The most affected countries have been today{\crq}s Byelorussia, Russia and Ukraine. Although international instructions and criteria for failure actions had existed even before the Chernobyl accident, the experience with their application was very limited. Needless to say, some short-term countermeasures had been neglected or insufficiently realised. Inhabitants were not informed about the accident in time and therefore they hid late. Also iodine prophylaxis did not start in time, which led to unnecessarily high irradiation of thyroid gland. The evacuation was, in view of decreasing external exposure, executed within possibilities efficiently. As for the long-term countermeasures related not only to the liquidation of the aftermath of the accident in the area of the nuclear power plant but especially the decontamination works in residential units and on contaminated soils, regulation of food chains and relocation of persons from the affected areas, preventive and health care of the inhabitants living in the contaminated territory - these measures were massive in scope and in principle mostly reasoned and effective. Unfortunately, the effectiveness of some of these measures was somewhat deteriorated by the fact they were introduced area-wide (only on the basis of the surface contamination and not on the estimation of exposure from whole-body measurements), were not fully substantiated and later had to by cancelled for economical reasons. Not only economical factors play an important role in the planning and application of the countermeasures (mainly long-term ones). Without question it is necessary to secure that the measures can be applied in the contaminated areas in view of their effectiveness in sufficient extent for time long enough and after a thorough evaluation of all pros and cons, expenses and gains. As well, it is needed to take into consideration the effect of social and psychological factors, where in practise a satisfactory progress has not been made yet. Many studies proved that the introduction of countermeasures affects the increase of psychosocial tension among the involved people. This negative attitude results from the public{\crq}s lack of information about radiation and about the possibilities of its reduction and consequent fear and anxiety due to the uncertainty regarding future. Because of the concealment of information about the Chernobyl accident, also distrust of citizens against authorities has remained to be a problem. However, the approach of public is very important in regard to the effectiveness of countermeasures. In order that the measures would be accepted as well as possible, it is needed to secure corresponding education programs and to engage public into discussions and decision-making within the introduced measures.
|
|
| |
|
| |
|
| |
guest ::
