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Dose analysis of the MAPE Mydlovary staff
RŮŽIČKOVÁ, Eliška
In the previous century a uranium ore chemical processing plant was constructed about 20 km from České Budějovice called MAPE Mydlovary, which employed approximately 1,100 employees at various times. We can assume that radionuclides affected the company's employees during the processing of uranium ore and the subsequent storage of waste in the adjoining sludge lagoons. They were irradiated by a total of three radiation components, which included gamma radiation, short-lived radon decay products and long-lived radionuclides from the uranium decay chain emitting alpha radiation. This is why this bachelor's thesis is devoted to analysis and evaluation of the percentage of individual radiation components in the total dose received by former MAPE Mydlovary employees. The purpose of this work is to establish how the individual radiation components were distributed in the doses of radiation received by former employees. The dosimetric sheets of former MAPE Mydlovary employees, who received all three types of radiation, were analysed in order to answer the research question. Dosimetric sheets were reduced so that each sheet contained all the required information. The established average annual doses of all three types of radiation and the total effective doses were converted into a graph, evaluated and subsequently compared with the valid legislation. On the basis of evaluation of the acquired data we can state that long-lived radionuclides from the uranium decay chain emitting alpha radiation made up the highest percentage of the radiation doses received by former MAPE Mydlovary employees, at a total of 49%. Inhalation of short-lived radon decay products made up 29% and external gamma radiation just 22%. The radiation limit for radiation workers of 20 mSv/year on the total effective dose from exterior radiation and on the committed effective doses from internal radiation was exceeded by 8 former employees according to our current legislation. We must state that no rules were broken according to Czech legislation valid between 1960 and 1970, because the limit for radiation workers was set at 50 mSv/year.
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The history of uranium mining with particular emphasis on the 21st century
FUKA, Stanislav
Uranium is a chemical element with the brand U discovered in 1789 by German chemist Martin Heinrich Klaproth. Initially it was not particularly interesting for mankind, it was used mainly for colouring the glass. A major turning point came after the Second World War, when uranus began to be used for nuclear weapons and later for nuclear industry. At that time Czechoslovakia was the great world power in the production of uranium. The aim of my bachelor´s work is a description of the uranium research characteristics and development of uranium mining in the 20st and the 21st century in the Czech Republic and in the world. An intergovernmental contract between Czechoslovakia and the Soviet Union about an uranium supply was signed in 1945. Jáchymov was the key place for the Soviet Union, there was only a research carried out in other places of Czechoslovakia. There were exported 98 500 tons of the separated uranium ore and the concentrate to the USSR. The uranium industry employed 40 000 people in the fifties of the last century and it should be mentioned that a considerable part consisted of inmates and prisoners. At the turn of the fifties and sixties, the supply for military purposes is filled up and the uranium begins to be used mainly for nuclear energy. The mining is reduced after 1989 mainly due to an overproduction of uranium. The uranium mines are gradually closed and the places of extraction and chemical finishing departments of the ore are recultivated. The only mine, which is still in operation, is in Dolní Rožínka in the Bohemian-moravian highlands. A significant problem nowadays after the extraction seems to be the location of Stráž pod Ralskem, where the uranium is mined by the method of chemical infusion (In Situ Leach), and the chemical finishing department of the ore, mainly a MAPE Mydlovary. The price of remedial work estimated at 40 billion Czech crowns in Stráž pod Ralskem and will last approximately for the next 20 years. Redevelopment in the 5 MAPE Mydlovary is estimated in the tens of billions of Czech crowns and it will take about another ten years. Bachelor´s thesis is divided into two parts. In the theoretical part, there are described the sources and methods of uranium mining, the concepts of radioactivity, uranit. After that there is described the current state of environmental burdens in the MAPE Mydlovary in Českobudějovicko. In the practical part I deal with the issue of the impact of uranium mining on man and the environment, the development in uranium mining in developing countries and the perspective of the extraction and a comparison of the uranium reserves in the Czech Republic and in the world. A section of the practical part follows up the development of the price of uranium in world market.
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Issues of chemical toxicity in the former of uranium ore processing plant MAPE Mydlovary
VENCLÍK, Zdeněk
Since 1986 extensive reclamation works have taken place in the area. Aim of this works is to mend the damaged environment, eliminate impact of uranium processing, reduce contamination of ground water and radiation effects on the area. However after 29 years of reclamation works, risks of chemical and radiation toxicity are still present. Massive development of uranium mining occurred at the beginning of 20th century. Czech republic was not an exception and czech government decided to build chemical processing plant of uranium under a code name MAPE. chemical processing plantwas built near village Mydlovary, in the southeaster part of Czech republic. Construction began in 1959. Operation started in 1962. Uranium was processed either by acidic or alkalic leaching. During the operation of the plant 36 million tons of sludge were stored in nearby sludge beds. Operation of MAPE ended in the year 1991. This thesis focuses on problems of chemical toxicity in former uranium processing plant MAPE Mydlovary and nearby area. Primary aim was to assess potential risks of chemical toxicity resulting from MAPE operation which could influence health of former employees, citizens of nearby villages and the environment. In order to determine the risks it was necessary to analyse chemical substances used to process uranium, possible signs of uranium intoxication of living organisms, quality and direction of ground water flow in wider area of interest. Among substances used to process uranium were different kinds of gasoline, diesel, ammonia, nitric acid, sulphuric acids and its salts, sodium carbonate and barium chloride dyhydrate. In comparison to dangerousness of particular substances it was found that most occurring types of damage are types of damage to skin or eyes due to irritant or caustic effects. It was difficult to analyse the influence of uranium intoxication on living organisms because of limited availability of useful and relevant information . Therefore assessment of possible effects were established as the result of previous studies. Former employees of MAPE could have been exposed to several kinds of uranium compounds (UO2, UO3, (NH4)2U2O7), therefore effects of intoxication by these compounds were taken into the consideration. Most cases of chemical intoxication were localized in the renal and respiratory systems of living organisms. Ground waters of wider area of interest were estimated as main carrier of potential chemical intoxication of residents of nearby villages and environment. Analysis of quality and direction of spreading showed that villages close to processing plant can use ground water only for irrigation (in the village Mydlovary ground water cannot be used even for irrigation) . Furthermore there is a small risk of contamination of collecting borehole S4 near the city of Zliv. Water from this borehole is drinkable and worsening of the quality of this water could result in exceeding limits set by decree no. 274/2003. Nowadays former chemical processing plant of uranium MAPE Mydlovary represents one of the most severe ecological burdens in Czech republic. Reclamation works significantly reduce negative impacts of chemical processing plantand without these works present situation would pose both real threat to ecology and protection of public health.
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The radiation exposure of employees of the former uranium ore processing plant MAPE Mydlovary.
NOVOTNÁ, Dana
In 1959, approximately 20 km to the north-west of České Budějovice a construction of a chemical uranium ore plant MAPE began. The plant operation started in 1962 and finished in 1991. The premises of the former chemical plant MAPE Mydlovary consisted of a plant in which uranium ore was manufactured and the manufactured material from uranium mines was stored in adjacent sludge lagoons. Uranium ore has never been mined in this area, neither in its surroundings. It has always been imported from uranium mines. Uranium was made from the ores by either acid or alkali leaching. Although this former uranium ore plant MAPE Mydlovary hasn´t been economically active anymore, it is nowadays one of the biggest environmental burden which results from ore mining and it's processing in the Czech Republic. Therefore, it is important to carry out remediation and recultivation works which are currently provided by the state enterprise DIAMO. DIAMO company, in fact, is also the owner of the former plant MAPE Mydlovary. During the operation of the former ore plant MAPE Mydlovary, about 1,100 employees took turns in the company. During the uranium ore treating and its consequent waste store in the lunge lagoons, employees of the plant were exposed to the effect of radionuclides. For this reason, my diploma thesis deals with the effect of radiation on employees of the former chemical plant MAPE Mydlovary and aims at the doses which the employees received while working in the plant. The data were gathered from October 2013 to April 2014 and contain figures for a period of 1963-1996. These figures were gained from personal dosimetrical files of the employees and these files were provided by the state enterprise DIAMO. The first aim of the thesis was to monitor the rate of radiation and to compare the gained values among individual employees of the plant MAPE Mydlovary. The monitoring of the effect of radiation was carried out from personal files of the employees and the measured values were put into tables of Excel programme. The values were then compared and I also used descriptive figures statistics. The doses at the employees were found not to exceed any dose limits. The second aim of the thesis was to evaluate the measured values at several groups of employees according to the type of the work they do. The division into individual groups was carried out according to the scale of received doses. It deals with a group of employees who worked at least for 6 months with dustiness, another group working in a sludge lagoon, another group of workers who were responsible for the main manufacture but weren´t exposed to any dustiness (according to the type of work, these people were then divided either into the first or the second sub-group) and also a group of other employees who had their own dosimeter- this group served as a comparative reference in a statistic research. The measures values were evaluated by a statistic research. For this type of research, we used a parametric testing and a so-called Fischer´s F-test, which was applied thanks the Statistics function in a table processor MS Excel 2010. For this test, we used the level of significance = 0,05. Through the statistic research, we have found out that the highest measured values appeared at the employees who were working in the main manufacture but without any dustiness. This group of people was ranked as the first group. The lowest amount of received doses appeared at the employees who worked in the main manufacture, without any dustiness and were put into the second sub-group. The hypothesis that the doses of the MAPE Mydlovary employees are different within the groups has been confirmed. The hypothesis that the doses at the MAPE Mydlovary staff didn´t exceed any dose limits for the staff has been confirmed as well. The hypothesis that the doses at the MAPE Mydlovary staff were different in certain groups was confirmed.
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Radiation-induced cancer in the population of villages around MAPE Mydlovary
KREJČÍ, Klára
In 1959, the building of chemical preparation plant of uranium ore MAPE Mydlovary was initiated in a small village Mydlovary, near České Budějovice. In October 1962, the operation and processing of the uranium ore started. During operation, about 17 million tons of uranium ore were processed and the material from processed uranium ores was stored into the contiguous sludge lagoons. The operation of this plant was terminated in November 1991. The premises of MAPE Mydlovary were partially liquidated, decontaminated and handed over for privatization, nowadays there are recovery and reclamation works in process. Even though, MAPE Mydlovary is nowadays one of the most dangerous strains for environment, which emerged after mining and processing of uranium ores in the Czech Republic. The projection is to liquidate the consequences of this process for many more years from now. In immediate closeness to the premises of MAPE Mydlovary there lie the villages Mydlovary, Olešník and Zahájí. It can be assumed that during the processing of uranium ores and subsequent storing of waste into the contiguous sludge lagoons there could have been some impact on the inhabitants of these villages by radio nuclides. The possibility that there are still some sources of contamination and effect on the inhabitants of the three neighboring villages cannot be excluded nowadays, even after almost 23 years after the shutdown of the plant. For this reason this diploma thesis is dealing with the effects of the preparation plant MAPE Mydlovary on the inhabitants of Mydlovary, Olešník and Zahájí, specifically on the amount of deaths due to cancer diseases of inhabitants of these villages. Data was collected from October 2013 till April 2014 and it includes figures from the period 1971-2010. It was collected using non-standardized interviews and was provided by practicing physicians of the investigated villages; furthermore, data was collected from websites of the Czech Statistical Office. Aim of this thesis was to analyze and compare the deaths due to cancer diseases of the inhabitants in the surroundings of MAPE Mydlovary and of inhabitants in the whole Czech Republic (whole republic´s cancer disease mortality) and evaluate the possible influence of the radiation load on the number of deaths due to cancer diseases of inhabitants in the surroundings of MAPE Mydlovary. The analysis and comparison of the number of deaths was carried out using statistical research. Non parametric testing was used for the statistical research and the so called Fisher exact test was used, which is carried out by means of statistical software www.ncss.com. For this test the level of significance - = 0, 2 was used. The influence of the radiation load on the number of deaths due to cancer diseases is statistically significant only in the village Mydlovary, where it is possible to prove statistically an increased number of deaths due to cancer diseases in comparison to the number of deaths due to cancer diseases in the whole Czech Republic. Based on the evaluation of the obtained data we can state that the chemical preparation plant of uranium ore MAPE Mydlovary most likely had and still may have a negative impact on the inhabitants of the neighboring villages, especially on the inhabitants of the village Mydlovary. For this reason it is very important to continue with the recovery and reclamation works in the premises of the chemical preparation plant of uranium ore MAPE Mydlovary and their main objective is to protect the inhabitants of surrounding villages against possible exposure to the radio nuclides. Nevertheless, the impacts of processing the former chemical preparation plant of uranium ore MAPE Mydlovary will be eliminated for many more years.
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Possible risks of abuse of radioactive materials from the former uranium ore processing plant MAPE Mydlovary.
ŘEPA, Libor
Possible risks of using radioactive materials are a highly discussed topic nowadays. This work is dealing with this problem and it is focused on possible risks of using radioactive materials from the ex-treatment plant of uranium ores MAPE Mydlovary. In introductory chapters I am describing the current state of ex-treatment plant of uranium ores. I am dealing with the history of operation of MAPE, information about sludge lagoons and about stored sediments in them and other characteristics concerning this operation. For years, sediments in which radionuclides are contained have been stored in treatment plants and that is why I am dealing with ionizing radiation. Because the topic is the using of radioactive materials which can be used mainly by terrorists, I am also describing this worldwide phenomenon of recent years where I first of all focused on super-terrorism using radioactive weapons, namely so-called ?dirty bombs?. The target of this work is to find out possibilities of using radioactive materials from the ex-treatment plant. Therefore I measured values of radioactivity and exposition of radiation at some places with the help of exploratory research. That meant sampling of soils and water and also measurement of power of dose equivalent of radiation gamma. After gathering information of needed radiation values I carried out simulation of possible using of radioactive materials from the premises MAPE. By means of dirty bomb I used the programme TerEx at using radioactive material. Then I carried out several calculations which were focused on inhalation, ingestion or outdoor radiation from radioactive materials and also calculation how much it is necessary to gain a significant source of ionizing radiation. From these sources I have deduced impacts for individuals, society or environment. Based on analysis and evaluation of given problems, my set hypothesis ?By using radioactive materials from the ex-treatment plant of uranium ores MAPE Mydlovary a serious threat to people will not occur? was confirmed. Results of my work can be used as a study material for completing and broadening knowledge about risks resulting from using radioactive materials. Further an increase of foreknowledge and explanation of certain consequences of ionizing radiation on humans from materials from the ex-treatment plant of uranium ores MAPE Mydlovary, for inhabitants of Mydlovary and surrounding areas and also useful information for lay and professional society which is interested in these problems.
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