Zugl.: Heidelberg, Univ., Diss., 2005

The thesis is generally focused on summarization of the information related to the high activity sealed sources of ionizing radiation, known as HASS, which are widely used in a variety of sectors in whole world and the Czech Republic as well. The thesis discusses specific cases of actual use of HASS, technical specification, types of occurring radionuclides and examples of use. The biological effects of ionizing radiation on humans related to HASS and some examples of specific adverse events are also described. In the intentions of this thesis is to take into account not only risks arising from incorrect manipulation, but also risks associated with potentially abuse of HASS by terrorist organization. For these reasons, the thesis outlines the basic security requirements associated to the international standards and also mentioned in legislation of CR. In connection with these requirements the suggestion of particular security system on specific workplaces with HASS is than discussed. To supplement the reader's imagination of the real problems of HASS in the Czech Republic, there is created a statistical overview of all HASS located in the Czech Republic. This includes the total number of HASS and the largest area of use devided into various areas of application (medicine, industry, research/education, etc.), representation of most commonly used radionuclides, the geographical distribution of HASS in the Czech Republic and the distribution in terms of the most common activities. The State Office for Nuclear Safety Registry was used as a source for this statistical overview. In the discussion part of the thesis, the real possibility of abuse of HASS and also a possible ways of gain from the perspective of a potential lone striker or a wider terrorist organization is discussed. In general, the following thesis is a logical synthesis of relevant information allowing the reader to obtain a relatively comprehensive view on the whole issue of HASS, especially from the perspective of the broader field of radiation protection emphasized on achieving a socially acceptable security level of all high activity sources of ionizing radiation.