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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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Radioactive waste management in the department of nuclear medicine
VENCLÍK, Zdeněk
Radioactive waste management in the department of nuclear medicine is a complex process in which it is necessary to obey a number of lawful orders. These are based on physical and chemical properties of the radionuclide sources. At present these regulations particularly include Act No. 18/1997 Coll., on Peaceful utilisation of nuclear energy and ionizing radiation (the Atomic Act) and amendment to and alteration of some related acts in the wording and implementing Decree No. 307/2002 Coll., on Radiation Protection (which repeals Decree No. 184/1997 Coll.) in the wording of Decree No. 499/2005 Coll., which amends the Decree of the Czech National Council for nuclear safety No. 307/2002 Coll., on Radiation Protection. This legislation regulates the management of radioactive waste as a whole and deals with specific radionuclides in the annexes. It is necessary to comply with legislation whether the radioactive waste is generated in the actual production of radionuclides or during their diagnostic and therapeutic applications. All production and application processes give rise to certain materials contaminated with radionuclide sources but without the possibility of their further use. These contaminated and unusable materials are called radioactive waste. Radioactive waste arising from operation of nuclear medicine is basically divided into solid, liquid and gaseous. Solid radioactive waste is collected in refrigerators and lead safe deposits, depending on whether the waste is infectious or not. Liquid waste goes through the process of dilution in most cases, when there is a decrease of the volume activity limits and subsequent discharge to sewer. Gaseous waste is a negligible component of radioactive waste produced at nuclear medicine departments, so it is not often dealt with in more detail. No matter what kind of waste, the process of its disposal has a common goal of reducing its activity below specified limits (clearance levels), so that the waste can be without greater risk moved or released and disposed of as other, non-radioactive waste.
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