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Radiation exposure of persons working in the risk of ioniing radiation in the University Hospital in Pilsen
ULČOVÁ, Radka
The diploma thesis on "Radiation exposure of persons working at risk of ionising radiation at the Pilsen University Hospital" is divided into two parts. The first analyses personal effective doses of the employees of the Pilsen University Hospital in 20092013, and the second focuses on measurements of secondary radiation created after the activation of collimator systems of linear accelerators. The introduction of the theoretical part discusses the history of radiology, followed by a summary of information on the sources of ionising radiation, its characteristics, properties, methods of interaction with the environment and biological effects on organisms. The chapter on radiation protection focuses on basic legislative regulations relevant to the topic. In the Czech Republic, radiation protection of people working with sources of ionising radiation is mostly based on Act No. 18/1997 Coll., on peaceful uses of nuclear energy, and Regulation of the State Office for Nuclear Safety No. 307/2002 Coll., on radiation protection. The thesis also lists dose limits and basic information about personal dosimetry, and the theoretical section is concluded with information on the methods of protecting personnel and on provided healthcare. The thesis uses as its sources primary literature, internet links, current legislation and data from the database of the State Office for Nuclear Safety on records from personal dosimeters in the analysed period. The thesis had two objectives. The first was to compare levels of exposure at the Pilsen University Hospital. The analysis involved 579 persons in total; after arranging the data into tables and dividing employees into groups by the type of tasks they perform and their job, it was possible to compare median value indicators, confirming the hypothesis that persons carrying out intervention tasks are exposed to more ionising radiation. In order to compare the development of doses over time, a double-selection t-test was performed on data from 2009 and 2013, confirming the effectiveness of anti-radiation measures adopted at the University Hospital and a reduction in the exposure of employees in this period. The second objective was to confirm or deny the hypothesis that secondary radiation created by collimator systems, while measurable, is not sufficiently large to be detected by personal dosimeters. In order to achieve this objective, measurements were carried out at the Oncology and Radiology Clinic of the Pilsen University Hospital. The first measurements tried to determine the relationship between dose and time at various levels of energy, the second compared the relationship between dose and distance from the collimator plane and the third monitored the number of exposures until the collimator plates are saturated and dose is no longer increased. All results were arranged in tables and projected in charts. The results of the research confirmed the hypothesis that secondary radiation created during the use of high-energy equipment is just below the detection limits of personal dosimeters. For this reason, it is recommended to frequently rotate personnel working with the equipment.
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The use of personal dosimetry on nuclear power plants abroad
KAUCA, Michal
There is performed the analyse of the use of personal dosimetry on nuclear power plants abroad compared with the situation in Czech Republic in this work. There is made the quality compare the usage of particular kinds of personal dosimetry on basis of informations got from choice nuclear operations, and the compare it with the situation in Czech Republic. I chose the way of getting of data by e-mail. On basis of got informations I made the compare as was objective this work. By compare of situation in radiation protection was found, the used personal dosimeters abroad and in Czech Republic are the same type almost. Some states including Czech Republic go over to legalization of personal electronic dosimeter as primary instrument of radiation protection. The matter of interest is the situation in Slovakia, where is receded from this type of dosimeter as primary and they returned to the previous type of dosimeters. Another speciality are the authorised limits for radiation worker in controled zone also for pregnant women in Japan. It isn´t usual in other states. This work refers to influence of personal dosimetry over the level of radiation protection in nuclear establishment and also over the connection of safety disposal in personal dosimetry with approved legislative in choice states, over the necessity of the controle, the competence of personal and also the progressive research and development in personal dosimetry. It is necessary to see the radiation protection globally. The personal dosimetry will have been not only national problem but also international matter. The new development in the sphere of passive and electronic dosimeters up to the complete global concepts of control is operationed already today in many states and it is offered in the international market still more often.
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Development of system reduction and limitation of doses in persons working with sources of ionizing radiation and in inhabitants
TEPLÝ, Antonín
Development of system reduction and limitation of doses in persons working with sources of ionizing radiation and in inhabitants This dissertation discusses a system of limits and its development, i.e. how did the radiation dose limits change due to the safety of staff working with ionizing radiation and how did the limits of exposure of the population change. The introduction part of this dissertation deals with basic principles of radiation protection, namely with its optimization {--} with ALARA system. In the Current situation chapter there is a system of limits for reduction of radiation (Sec. 18 and 22 of the State Office for Nuclear Safety Decree No 307/2002 Sb.) and derived limits. The main part of this project focuses on monitoring of the practical development of the system of limits. In the Radiation Oncology Institute of the Faculty Hospital Na Bulovce (Ústav radiační onkologie Fakultní nemocnice Na Bulovce) archive I received data from the CSOD. I processed listing of both free-month and one-month doses received by the staff and I studied the way the doses decrease and mainly how does the number of personnel in whose cases the doses exceeded their limits decrease. I involved three most numerous groups of personnel. The first group consists of radiology assistants and analysts, the second group consists of medical doctors and physicists and the third group consists of medical nurses who were monitored only till 2003. The greatest decrease can be noticed since 2003 when the listings of radiation doses started being evaluated on monthly basis. I think that monthly evaluation of doses is a great landmark in the issue of protection of personnel involved with ionizing radiation. I transferred the data about these doses into several charts. I divided exceeded doses into individual scales and processed them statistically. There is a table in the discussion part of this dissertation work where even historical dose limits and dose equivalents are converted to mSv units (i.e. mSv/year) so that it would be possible to compare the limits. The process of radiation protection of the personnel in the Institute is also dealt with.
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Monitoring the personnel radiation load in percutaneous interventions
SKÁCELOVÁ, Lada
The discovery of ionising radiation at the turn of the nineteenth and twentieth centuries was a landmark for medicine: the methods based on the principle and effects of ionising radiation are used even in the present medicine to a considerable extent. As early as in the very beginnings, adverse affects of ionising radiation were observed, and from this early period the first references to the need of radiation protection date. The fields of medicine dealing with the application of ionising radiation, whether in the diagnosis or in the therapy of diseases, went through an extensive development in their over hundred-year history. It was in the technical sphere in particular where the most important progress was accomplished, thanks to the ever more advanced instrumentation put on the market, meeting the strict criteria of radiation protection. On the one hand, a large group of diagnostic and therapeutic procedures was replaced by new methods (based on ultrasound and magnetic resonance) that are not based on ionising radiation, and thus the patient or the attending personnel are not exposed to the harmful effects of the radiation. On the other hand, the interventional radiology has attained an unprecedented expansion. With the development of new interventional methods and procedures, the number and duration of interventions has been growing. The radiation load to which the intervening personnel are exposed has thus been rising despite the state-of-the-art instrumentation. The theoretical part of the dissertation describes the origin and types of the ionising radiation, its properties and interactions with the environment; a proportional part has been devoted to the biological effects of the radiation. The prime attention has been concentrated on radiation protection, its objectives, principles and methods of radiation protection. An overview of the current legislation and list of requirements on the radiation monitoring has been elaborated. In the chapter on personal dosimetry, the fundamental relations and quantities used in the radiation dosimetry have been described, as well as the types of personal dosimeters and protective equipment. In the practical part, the radiation load of the personnel attending percutaneous interventions in the department of interventional radiology of the Clinic of Radiology of the Teaching Hospital Olomouc was measured. Personal electronic radiation dosimeters Rados, type RAD 60S, were used. All the data obtained were processed using statistical methods, and, on the basis of the results thus obtained, the effectiveness of protection was determined, and the importance of the observation of the principles of radiation hygiene was evaluated. The presumed use of the results of this work in practice is in the optimisation of procedures and measures leading to the maximum possible reduction of the radiation load in percutaneous interventions, and to the education and guidance of personnel towards consequential compliance with all principles of the radiation hygiene.
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