|
| |
|
|
Application of semiconductor gamma spectrometry in experimental reactor physics
KUČERA, Jan
In the present bachelor thesis, a database for efficiency calibration of a gamma-spectrometry device with cascade summing correction was built using software developed by the company Canberra. The formation of the database consists in the construction of a model for a shielding of semiconductor detector and of models for measured radioactive samples with various geometries. The designed model was tested on measured spectra of gamma radiation and a selected calibration curve was compared with the results obtained by Research Center Rez using the MCNP method. Moreover, several theoretical results were obtained in the course of this work, including the technical parameters and usage of experimental reactors at Research Center Rez and the principles of gamma radiation spectrometry in the LR-0 reactor.
|
|
|
Risk assessment associated with the release of radioactive iodine from nuclear medicine department during a fire
RAMBOUSKOVÁ, Lucie
Nuclear medicine is the branch of medicine that is used to diagnosis and treatment with radioactive isotopes. Nuclear medicine is one of the least burdensome non-invasive methods of investigation. In contrast to diagnostic radiology, which shows the structure of organs , nuclear medicine provides information not only anatomical , but also on organ functions and metabolism. In many cases it is a unique diagnostic test that can detect the disease or its extent before, and thus increase the chance of successful treatment. When working with open emitters for nuclear medicine department can be assumed that may occur in the expected manner of use of radioactive sources only incident of First Instance ( spilling or splashing radiopharmaceuticals, patient pollution ) and very rarely an emergency occurs the second stage (the loss or theft of resources radiation). An extraordinary event is the third-degree radiation accident with very minimal probability of occurrence. The aim of the Bachelor thesis is to map the distribution and the storage of radioactive iodine in the Department of nuclear medicine of the hospitals in the Czech Republic, to determine the level of knowledge of the medical staff and members of the fire rescue Corps and their application in practice, in the release of radioactive iodine, and assess the degree of risk associated with the release of radioactive iodine in the fire. The hypothesis assumes that the medical staff and members of the fire rescue Corps know how to proceed in cases of leakage of radioactive iodine from the Department of nuclear medicine, and that the level of risks associated with the release of radioactive iodine in the fire is negligible. It is a form of qualitative research, research-questionnaire and interview-driven method. In an interview, polootevřený will be used and the type of closed questions. The research staff of the Department consists of a set of nuclear medicine and the members of the fire rescue Corps. Thesis will be used for more detailed study of the issue. It may also be used in lectures and seminars, health workers, and a fire department Rescue Corps.
|
|
|
Biodosimetry for persons exposed to alpha radiation: dependence on malignity (exp. work).
KŘÍŽOVÁ, Marcela
In the thesis I focus on evaluation of the effect of familiar occurrence of cancer on presence and number of micro-nuclei in blood preparations with particular groups of persons. One of the biodosimetry methods, test for presence, number and kind of micro-nuclei, was used. I was not investigating the dosages as such and connection of the number of micro-nuclei with the dose, however, I followed up the effect of potentially influencing side factor on presence and number of micro-nuclei, which is the familiar occurrence of tumour. As a lot of information about ionizing radiation, its sources, radioactivity, radio-biologically important quantities, mechanisms of effects, molecular and cellular changes and biodosimetric methods as such falls under the topic, the theoretical part of diploma project is dedicated to such information. In the practical part, evaluation of the number and kind of micro-nuclei with set groups of persons is carried out. These groups of persons are particularly exposed to ? radiation. They are employees of spa Lázně Jáchymov, former miners from already closed uranium mines in Příbram and current miners from uranium mines GEAM o. z. Dolní Rožínka. These selected persons are divided according to their workplaces into two groups, i.e. a group of persons without cancer occurrence in the family and a group of persons with occurrence of cancer in their families. The numbers of bi-nuclei cells without micro-nuclei and with micro-nuclei and the kinds of micro-nuclei were determined with all these persons using fluorescence microscope. Expression and comparison of percentages of bi-nuclei cells with micro-nuclei to total number of all bi-nuclei followed and then expression and comparison of proportion of micro-nuclei without centromeres to the number of micro-nuclei of both kinds (with centromeres and without centromeres) with all persons and groups were carried out. Based on the results gained from statistical assessment, it was found that differences between percentages of the two main compared groups of persons did not show higher genomic instability (statistically significant difference) in persons with familiar occurrence of cancer than in persons without cancer in the family. But by comparing the shares of micronuclei without centromeres was proved statistically significant difference between these main groups.
|
|
| |
|
|
The system of the safe storing of radioactive waste
NEUMANNOVÁ, Kateřina
We can hardly imagine today{\crq}s modern word of 21st century without usage of nuclear energy and ionizing radiation. We meet them in nuclear energetics, industry, health service and other different fields. Similarly to other human activities even here waste rises {--} radioactive waste which can be dangerous for a man and for the whole environment. Therefore it is very important to deal with it according to existing rules. Radioctive waste rises even in the Czech Republic and that is why an enhanced attention is very necessary here. Therefore I would like to break into these problems as much as I can and I would like to describe these problems in my bachelor work so that everybody is informed about basic information how to deal with radioactive waste in an understandable form. I think that everybody in this country, regardless to their education, should have a basic overview about problems of radioactive waste. I would be very pleased if this bachelor work could help people interested in these problems and if my work is used as an educational material. If readers find new interesting information, my work will be even more useful.
|
|
|
Health and safety at work with sources of ionizing radiation in healthcare
Pěnková, Jana ; Spirit, Michal (advisor) ; Soušková, Milena (referee)
The aim of this diploma thesis is to analyse health and safety system in department of nuclear medicine in Kolín hospital and evaluate its compliance with czech legislation. The thesis is compsed of four chapters. Chapter One gives a general introduction to health and safety issues and describes most important aspect of general health and safety legislation. Chapter Two explains the basic terms of ionizing radiation and radioactivity and focuses mainly on radiation protection, which is closely linked to the health and safety area. Chapter Three defines the legislative and institutional framework of health and safety in the area of ionizing radiation. This chapter is a starting point for Chapter Four, which analyzes the health and safety system in department of nuclear medicine in Kolín hospital, compares it with legislation requirements and evaluates the compliance.
|
|
|
The study of radioactivity and radiation problems and their comprehension by laical public
DVOŘÁKOVÁ, Romana
Radiation and radioactivity {--} these words awaken a sense of insecurity, unknowingness and sometimes even major concerns in many of people. On the other hand, only few people really have the right and sufficient information on this topic that is considered very important but also complicated and hard to understand. In my opinion, the majority of the public has no access to professional information on use of ionizing radiation and radioactivity. Therefore, they have insufficient knowledge of the topic and this fact results in concerns and fear of radiation that the public may hold. The hypothesis whether the amateur public is mainly afraid of medical sources of radiation, was determined for research in my bachelor thesis. Furthermore, I set several sub-hypotheses in order to gain a general picture of the points at issue and eliminate any ambiguous results. Moreover, the quantitative form of research was selected in order to reach the targets and verify the hypotheses. A questionnaire was used as a technique for collecting data. Members of the amateur public {--} patients of the hospital Mulačova nemocnice s r.o. in Pilsen {--} were selected as the statistical set for the purpose of the questionnaire survey. The objective of the thesis was to establish the concerns connected with various types of use of radioactivity and ionizing radiation, provide the objective and coherent perspective of the level of the amateur public{\crq}s awareness in this field, and propose the most effective way of presentation of information in order to spread the general awareness based on the data acquired and statistically processed. I would like to provide my bachelor thesis as a source of information to the general public. Furthermore, I would like to offer the results of this thesis to organizations dealing with these points at issue and as a course material for students of the University of South Bohemia in České Budějovice.
|
|
|
Radionuclides in the environment
LEVÝ, Leoš
Radionuclides occurring in the environment on Earth can be divided according to the mechanism of their origin into three main groups. Cosmogenic radionuclides are formed by continual cosmic radiation on the nuclei of stable elements especially in the upper levels of the atmosphere. Terrestrial radionuclides originate directly on our planet. The last group represent anthropogenic radionuclies which occur in the environment due to a controlled activity of man (e.g. nuclear plant outlets) or due to various accidents (the Cernobyl nuclear plant accident). For all mentioned radionuclides I give a description of their occurrence and concentration in the environment and their proportion on the total effective rate a man receives per year. Due to the fact that radon can represent up to 50 % of the total effective rate, it is dealt with in a special chapter. The paper aims at creating a unified overview of occurrence of radionuclides in the environment. To carry out this paper I presumed that there is an insufficient awareness in the inhabitants of the Czech Republic concerning this issue (lack of interest on the part of the population, reception of unverified, incomplete or misrepresented information from mass media or various interest groups). The questionnaire survey, the results of which are part of this paper, confirmed this premise and therefore it is possible to use this paper to improve the awareness concerning the dealt with issue.
|
|
|
Estimation of Tritium Activity in the River Vltavawith Respect to the Liquid Wastes from the Nuclear Power Plant Temelin.
ŠKOPEK, Petr
The main goal of this Thesis was to measure tritium activity in the Vltava River and in the vicinity of Temelín Nuclear Power Plant (hereinafter referred to as JETE) with the following objectives: Possibility to use the outlet of waste water damping unit (hereinafter referred to as VTOOV) as a control alerting system for nonstandard events in JETE, furthermore, monitoring of possible correlations between volume activity of tritium measured in VTOOV and activity above the limit value of the first quality class in selected sections of the Vltava River as well as comparison of the measured values with the results of other authors, and, finally, assessment of the relevance of the water quality estimated by the volume activity of tritium to the water quality according to other ingredients, i.e., stable isotopes of some metals and risk elements as well as general physical and chemical indicators. Theoretical part of the Thesis deals with radioactivity in general, activity of tritium, with regard to operation of nuclear plants, over the world and, especially, in the Czech Republic. The actual work consisted of collection of samples at predetermined places, preparation of these samples for measurement and measurement of tritium activity using scintillation spectrometer with liquid scintillator. Furthermore, basic chemical and physical properties of water, concentration of selected elements and also some anions were determined. The collected data were used for classification of waters from individual collection places into quality classes according to ČSN 75 7221. In all analyzed cases no activities were found which exceeded the limit values of liquid outlets from Temelín Nuclear Power Plant, given by regulations issued on waters by the District Health Office in Ceske Budejovice according to §8 of Act No. 138/73 Coll., in compliance with SÚJB requirements. This Thesis could be beneficial for possible utilization of VTOOV as a control alerting system for nonstandard events in JETE and also for assessment of impact of wastewaters from JETE on waters of the Vltava River.
|
guest ::
