Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 164-168).

Thesis (M.Soc.Sc.)--University of Hong Kong, 1987. / Also available in print.

The thesis deals with statistical investigation of selected tasks in population protection in emergency planning zones of nuclear power plants.The issues of population protection have been developing since 1930s up to now.Currently,the population protection is addressed particularly in concepts of population protection,while the most recent one is the Population Protection Concept until 2020 with an Outlook to 2030.The objective of the thesis was to compare awareness of the population in emergency planning zones of nuclear power plants.With regard to a potential extraordinary event,in this case a radiation accident,the awareness of the population plays a significant role.The theoretical part of the thesis analyzes population protection,legal regulations and documents dealing with this topic.It also defines measures in population protection which seek to mitigate impact of extraordinary events or emergency situations on health and lives of the population,property and the environment.The thesis also mentions emergency planning and describes types of emergency plans.The second section of the theoretical part describes selected statistical methods.The last chapter of the theoretical part describes methods of multidimensional statistics.The following hypotheses and partial hypotheses were formulated in the research part of the thesis to meet its objective: H1 There is no statistically significant difference between the emergency planning zone of the nuclear power plant Temelín and the emergency planning zone of the nuclear power plant Dukovany.H11 There is no statistically significant difference in awareness among men about a potential extraordinary event at NPP Temelín and NPP Dukovany.H12 There is no statistically significant difference in awareness among women about a potential extraordinary event at NPP Temelín and NPP Dukovany. H2 The awareness of the population in emergency planning zones of both the nuclear power plants has a theoretical distribution which is close to the normal distribution.H21 The awareness of the population (men) in the emergency planning zone of NPP Temelín has a theoretical distribution which is close to the normal distribution.H22 The awareness of the population (women) in the emergency planning zone of NPP Temelín has a theoretical distribution which is close to the normal distribution.H23 The awareness of the population (men) in the emergency planning zone of NPP Dukovany has a theoretical distribution which is close to the normal distribution.H24 The awareness of the population (women) in the emergency planning zone of NPP Dukovany has a theoretical distribution which is close to the normal distribution.All the formulated hypotheses were tested with methods of descriptive and mathematical statistics. The research was conducted with questionnaires handed out in the emergency planning zones of NPP Temelín and NPP Dukovany.The questionnaire consisted of 23 questions and it was filled out by 242 men and 270 women in the zones.All data used in the research were provided to me within the project "Population protection depending of differentiation of the population" safety survey (VG20132015122) performed at the department of radiology,toxicology and population protection at the Faculty of Health and Social Studies at the University of South Bohemia in České Budějovice in cooperation with the Fire Rescue Service of the Czech Republic.Results of the research have shown that the average awareness of the population living in the emergency planning zones of the nuclear power plants is less than 50% and that the knowledge of the population about a potential extraordinary event is not satisfactory.The population living in emergency planning zones of both the nuclear power plants could be exceptionally prepared for a potential non-standard situation, not only in the form of a Gauss curve.

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.

The thesis deals with the communication of the Temelín Nuclear Power Plant. Nuclear sources of energy are currently a sensitive issue. The planned extension of the Temelín NPP is also a frequently discussed topic in the Czech Republic; it affects many stakeholders and faces increased public and media interest. The goal of the thesis is to create a communication strategy of the Temelín NPP targeted to the public. The draft of the strategy is based on the conclusions of the SWOT analysis focused on the Temelín NPP communication, furthermore, on the analysis of selected online communication tools used by the Temelín NPP, and mainly on the quantitative survey conducted with the purpose to find out the actual public perception of the Temelín NPP and the public attitude to nuclear energy in general. The strategy also uses the knowledge of the company ČEZ media analysis and the findings of the sociological survey among inhabitants of the area close to Temelín compiled by STEM/MARK research agency.

The subject of this work is the repair of an air-handling unit. Possible causes of the problem are analyzed and multiple solutions are proposed. The first variant considers the refurbishment of the damaged component using thermal spray technology, including the choice of the best method. The second solution proposes the manufacture of a new part using machining in the environment of the company. This process requires an intermediate product to be made, and the choice of the correct machines from what the company has available, choice of the right tools and cutting conditions. The technical-economical evaluation compares the the expenses tied with both of the solutions. The chosen repair solution was used for the repair of the air-handling unit.

The goal of this thesis is to simulate the course of events during Dukovany Nuclear Power Plant blackout and to determine the optimal process of cooling down the cold branches of the primary circuit loops to secure the maximum amount of the primary fuel needed for the residual heat outlet so that the operating staff has as much time as possible for renewing the electric power supply. The first part of the thesis describes nuclear power plants built in the Czech Republic and in the world as well as reactor blocks whose construction is being considered. The detailed description of Dukovany’s steam generator is shared in chapter three. Following chapter summarizes blackouts that occurred at power plants around the world, events that might have led to blackouts in the Czech Republic, and it also describes current approach to blackout problematics at Dukovany Nuclear Power Plant. Chapters six and seven contain the core of the thesis. That includes detailed description of a mathematical model explaining the behaviour of a reactor block during blackout as well as the analysis of the results found.

The master's thesis deals with the analysis of source term of the spent nuclear fuel of the Dukovany Nuclear Power Plant in order to determine the proposals for the transfer of spent nuclear fuel to a deep geological repository in the Czech Republic. To introduce the reader into the issue are briefly described the main aspects, such as the development of the nuclear fuel used in the history of the Dukovany Nuclear Power Plant. These aspects have an influence on the final draft of the timetable. One of the important partial tasks is the processing of an estimate of the future range of spent nuclear fuel, which is based on the current ideas of company ČEZ, a.s. for the future direction of the fuel cycle at the Dukovany nuclear power plant. For the purposes of this work, the key data are the time dependencies of radioactivity and the development of residual heat in individual fuel assemblies. This data are calculated by the software called PAL440_R4, based on the prepared estimates of the spent nuclear fuel assortment. The calculated data are then edited and sorted by MS Excel. For the sake of completeness, the characteristic values and the time dependencies of the radioactivity and the development of residual heat in fuel assemblies. Final timetables for the transfer of spent nuclear fuel to a deep geological repository are processed in several variants, and their selection and application options are justified. For illustration are important parameters given in the form of tables and charts.

Viscous dampers are widely used to ensure seismic resistance of pipelines and equipment in nuclear power plants. Damping characteristics of these dampers are nonlinearly frequency dependent and thus causing complications in computational modelling of seismic response. Engineers commonly use two ways to deal with this nonlinearity: The first option is to consider damper by means of “snubber”. This is essentially linear spring element that is active for dynamic load and does not resist static loads. Snubber behaviour during seismic event is described by a equivalent stiffness (sometimes called pseudostiffness). The equivalent stiffness could be defined by the iterative calculations of piping natural frequencies and mode shapes taking into account seismic excitation. However, in complicated structures such as the main circulation loop of nuclear power plant the iterative calculation is difficult and could bring significant inaccuracies. On the other hand, the benefit of such modelling is a possibility to apply the commonly used linear response spectrum method for a solution. The second option is to describe damping characteristics using suitable rheological model. The seismic response is than determined by direct integration of the equations of motion. The behaviour of dampers is described exactly enough but the calculation and post-processing, especially nodal stresses time-histories, are time consuming. The goal of this work was to find a methodology for determining the seismic response of complex pipe systems with viscous dampers. Methodology allows a sufficiently accurate determination of the seismic response of piping systems and also allows obtaining of the results in effective time. The procedure is as follows. Firstly, specialized piping program (AutoPIPE) is used for the development of computational model. Next step is to determine a static response of structure and its verification with experimental measurements, if possible. Using script in Python language a computational model is converted from AutoPIPE into general finite element model in ANSYS system. Four-parameter Maxwell rheological model is used to describe behaviour of viscous dampers. Seismic load is represented by synthetic accelerograms. Newmark algorithm of direct integration of the equation of motion is used to obtain seismic response (only reactions and displacements in nodes of interest are necessary). Than is the equivalent stiffness is than gained from displacements and reactions as median value of their ratios. Received stiffness are subsequently transferred to AutoPIPE program where the seismic solution is performed using response spectra method. Finally, the dynamic response is combined with the static response and stress assessment according standards is done. The created methodology was applied in the seismic resistance calculation of the main circulation piping and piping of pressurizer in nuclear power plants type VVER 440 and type VVER 1000.

This thesis is focused on the design of passive cooling system for a nuclear reactor VVER- 1000.This type of reactor is located in the Czech Republic in the location of Nuclear power plant Temelín. The thesis states an overview of the different cooling systems of nuclear power plants. The thesis is focused on passive safety system especially on passive cooling system, so there was done an overview of currently used passive safety system. In the work is discussed nuclear safety and the maximum projected accident of VVER-1000, which is called LOCA accident. In the design part of the thesis was done thermal calculation of heat exchangers. Exchangers are designed as condensers with a natural flow, where cooling of system is provided by outside airflow in case an accident. The results are evaluated at the end of the thesis.