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Surface contamination of optical elements studied by Low Energy Ion Scattering LEIS
Sekula, Filip ; Kolíbal, Miroslav (referee) ; Průša, Stanislav (advisor)
This thesis focuses on study of surface contamination of optical elements using the low energy ion scattering method, LEIS. Presence of surface contaminations on optical elements has a negative contribution on thin layers that are applied upon them. The contamination can occur between the steps of manufacturing process. By determining the composition of the contaminations it could be possible to increase effectiveness during the growth of thin layers. Measurement is realised on right angle prisms at room temperature. We also focus on construction of sample holder that would allow heating of samples in the preparation chamber. Later we measure reference spectra for quantification of surface contamination.
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Surface contamination of optical elements studied by Low Energy Ion Scattering LEIS
Sekula, Filip ; Kolíbal, Miroslav (referee) ; Průša, Stanislav (advisor)
This thesis focuses on study of surface contamination of optical elements using the low energy ion scattering method, LEIS. Presence of surface contaminations on optical elements has a negative contribution on thin layers that are applied upon them. The contamination can occur between the steps of manufacturing process. By determining the composition of the contaminations it could be possible to increase effectiveness during the growth of thin layers. Measurement is realised on right angle prisms at room temperature. We also focus on construction of sample holder that would allow heating of samples in the preparation chamber. Later we measure reference spectra for quantification of surface contamination.
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The evaluation of radiation burden of patients and the possibility of radiation emergence and management of emergencies at the nuclear medicine department of the Hospital České Budějovice, PLC
DAŇOVÁ, Kristína
The aim of my thesis was to evaluate radiation consequences in patients, and to evaluate unusual occurrences stemming from radiation at the department of nuclear medicine in hospital Ceske Budejovice. In the theory part, I worked with professional literature, applicable laws and internal documentation provided by the department of nuclear medicine in hospital Ceske Budejovice Plc The thesis reacted to the need of the department of nuclear medicine (dept. NM) in hospital Ceske Budejovice to evaluate the optimisation of doses for the patients and set local diagnostic levels. Different organisations worldwide deal with the question of optimising radiation protection, and their recommendations and standards are used in the Czech Republic. For this purpose, it is necessary to know the real activity of radiopharmaceuticals applied in each examination and to conduct a forecast resulting in effective doses also based on CT scans. The thesis also evaluates the occurrence of special radiation events really experienced at the department of NM (nuclear medicine) in the hospital mentioned above, the reasons for these events happening and precautions preventing them from happening in future. The owner of the permission for this activity, meaning the use of the source of ionizing radiation, has the duty to keep all documentation and paperwork in accordance with the law regulating nuclear power, abide by the rules of good practices and the real state of allowed practice. The occurrence of unusual events is closely connected with the documentation - internal emergency plan and monitoring program. (Law 263/2016) Therefore, it was recommended to compare these to the actual state and to review them based on the facts found. The values of applied activities and effective doses found were compared to the values published in the last report from UNSCEAR in 2016 and national referential values published in the bill about radiation protection no 422/ 2016. All results were inputted into tables and graphs. It was found that the applied activities at the department of NM in hospital Ceske Budejovice are in agreement with the values presented in UNSCEAR report and that they are lower than the national referential levels, which shows that there is optimised state of radiation protection for patients. The occurrence of concrete unusual radiation events at the department of NM in hospital Ceske Budejovice and their analysis revealed certain shortcomings in the process and the absence of security elements needed while holding radioactive liquid waste in storage at the hospital. It was necessary to find and implement such precautions, which will prevent similar type of events in future. The thesis will be handed in to the person tending to the radiation protection for the use of evaluation and providing the protection at the department of NM at the hospital Ceske Budejovice and to enable the documentation to be completed for the allowed activity.
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Hazards at Work in Temelín NPP Radiation Controlled Area.
KRČMÁŘ, Martin
During activities in controlled area of Nuclear Power Plant Temelín it is necessary to take certain measures with regard to the risks associated with ionizing radiation. These are primarily the requirements for protective equipment for individuals or workgroups. Principles and methods of storage material and technology, both at the workplace and outside. Necessary unavoidable introduction and salvaging objects across the boundary of the controlled area, whether it is tools or parts of the technology to be repaired or revised. At the workplace, there is a diverse waste that needs to be temporarily stored, sorted, and then passed to the workers involved in the disposal of this waste. The aim of this bachelor theses was to analyse existing methods and techniques used in operations in controlled areas, to check the reliability and adequacy of existing measures and procedures. Based on the performed analysis to propose measures to improve conditions for work in controlled area. Based on the study of expert resources and relevant legislation the theoretical part was developed. In the practical part, an analysis of several model activities that come into consideration in the controlled area of the Nuclear Power Plant Temelín was performed. Various changes were combined at the model activities with respect to both the workplace environment (source of ionizing radiation, surface contamination etc.) and various types of work (grinding, cutting, welding etc.). Also, methods of waste management, transports of technology or tools across the boundary of the controlled area were not omitted. Based on the analysis, it is possible to state that there were no serious deficiencies or reserves found in the measures used to prevent the risks related to the activities in the controlled area. The measures are not only fully functional, but the quality is at a high level. Also, we can not miss continuous effort of radiation control personnel to search for reserves and improvement, mainly due to acquired knowledge and experience in operation of the nuclear energetic device.
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Behavior of Personnel in Radiation Controlled Area /RCA/ in the Temelín Nuclear Power Plant.
SKOKOVÁ, Libuše
My bachelor´s work aims at measures and conventions of radiation protection of persons working in Temelín nuclear power plant radiation controlled area, mainly at using of personal work protective aids. The theoretical part gives description of measures and conventions for work in radiation controlled area and for usage of basic also special work protective aids, next of procedure for enter into/exit out from radiation controlled area, and description of barriers with measuring devices, where is carried out check of persons also clothing's surface contamination. Contains also description of personal doses optimalization system and of tools, used for implementation into practice. Detailed description of rules for usage of work protective aids, according to specific work conditions and radiation conditions, is included in this bachelor´s work. The main research part of this work are summaries of records about persons crossings of persons radiation controlled area borders, and about events of catching persons in measuring devices due to contamination. This summaries are processed into tables and graphs form and arranged so, that relationships between protective aids usage and contamination of workers are obvious. The aim of my work was to establish, whether presently applied rules of radiation protection are followed consistently and if there is a necessity for changes and improvement. For this finding were used all information about controlled area traffic, accessible legislation, statistical data from electronical personal dosimetry system and from electronical nearmiss, events and incidents database. The key findings are data and records about cases, when was necessary to dispose contamination of body surface by medical intervention. and about cases of body internal contamination. Medical interventions were necessary only rare, in year 2016 two times, during previous five years not once. There was not one case of body internal contamination throughout the whole time of Temelín nuclear power plant radiation controlled area operation. After evaluation of all the data, there is obvious, that measures and conventions of radiation protection, applied in Temelín nuclear power plant, are sufficient a there is no necessity of changes.
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Devices of radiation protection on the new nuclear source
LEŠTINA, Lukáš
The aim of the bachelor thesis is mapping the market with portable radiation protection devices offered by manufacturers specialized in nuclear measurement electronics, like Thermo Scientific, Canberra Packard and VF Černá Hora and subsequent comparison of for the purpose of finding operationally optimal solution of portable instrument for measurement of radiation quantities on a new nuclear source. At the beginning the reader is familiarized with occurrence of ionizing radiation, physical principles the instruments are based on and the radiation quantities by which the instruments interpret the final values. There is a description of the present state of portable measurement technologies used by radiation protection staff at Temelín Nuclear Plant. The description includes basic information, photos and specifications. A methodology with criteria of selection of new portable instruments was elaborated upon experience with the plant operation. Selected instruments from the large range by nuclear electronics manufacturers are described in an extra chapter. The discussion focuses on user comfort and suitability of the instruments based on the real situation of Temelín Nuclear Plant. Attention is also paid to versatility of the instruments and possibilities of their extension by additional devices like external probes of dose equivalent input, surface contamination or probes measuring dose equivalent input of neutrons. The instruments should correspond to the needs of the radiation protection staff as much as possible, so as they are able to fulfil the programme of monitoring on a new nuclear source in the most efficient manners.
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Measuring methods of surface contamination with radioactive substance in the nuclear power plant Temelin
PAPAN, Juraj
Monitoring of the occurrence and scope of surface contamination is performed by the Radiation Protection department in order to adopt adequate measures for the protection of persons from unwanted contamination and to inspect observation of limits for surface contamination and for items taken outside the controlled area. The chapter containing results and collected data includes a definition of the measured parameter and it stresses the surface contamination as a major health risk factor, which is demonstrated by conversion of surface contamination values into absorbed doses in the exposed body organs. This is followed by the principles, issues and factors affecting detection of ionizing radiation, particularly the surface activity, which is used to express the extent of surface contamination. The issues of detection are followed by a description of scope and principle of monitoring implementation within which the individual measurements are performed, taking into account the reference levels for specific measurements. The individual measuring procedures are accompanied with descriptions of their use. Apart from a summary description of the implementation of surface contamination monitoring in the nuclear power plant Temelín, one of the objectives of the thesis was the analysis of errors introduced into the measurement process by persons performing the measurements. The main objective of the thesis was to confirm the hypothesis that measures adopted by the Radiation Protection department, based on results from working measurements for the protection of workers who get into contact with radioactivity in form of surface contamination, are sufficient and that the limits for surface contamination of items taken outside the controlled area are not exceeded.
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Surface roughness and resistivity of thin films
Franc, J. ; Novotný, Jan
Surface finish of alumina thin film substrates was measured with stylus profilometer. A connection between the obtained values of Ra and the thin film resistance was studied. No correlation can be found owing to big stylus radius and computation method used in profilometer.
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