[en] In these paper the operation of the radioactive waste storages in the Czech Republic is explained

[en] In this paper environmental impacts of radionuclides and other pollutants released into environment from nuclear power plants (NPP) and coal fired power plants (CFPP) are compared. Assuming coal contains uranium and thorium concentrations of 1.3 ppm and 3.2 ppm, respectively, each typical 1000 MW_e CFPP released 5.2 tons of uranium (containing 36.92 kg of U-235) and 12.8 tons of thorium. Total releases in 1990 from worldwide combustion of ∼3300 million tons of coal totaled ∼4552 tons of uranium (contains ∼32317 kg of uranium-235) and ∼10860 tons of thorium are estimated. Based on the predicted combustion of 12,580 million tons worldly during the year 2040, cumulative releases for the 100 years of coal combustion following 1937 were predicted to be Planetary release (from combustion of 637,409 million tons): uranium: 828,632 tons (containing 5883 tons of uranium-235); thorium: 2,039,709 tons. According to the NCRP, the average radioactivity is 427 μCi/t of coal. This value was used to calculate the average expected radioactivity release from coal combustion. For 1990 the total release of radioactivity from worldwide 3300 million tons coal combustion was, therefore about 1,41 MCi. Another unrecognized problem is the gradual production of plutonium 239 through the exposure of uranium-238 in coal waste to neutrons from the cosmic rays. Other environmental impacts from NPP and CFPP are discussed. The fact that large quantities of uranium and thorium are released from CFPPs without restriction increases a paradoxical situation. Considering that the nuclear power industry has been compelled to invest in expensive measures to greatly reduce releases of radionuclides from nuclear fuel and fission products to the environment, should coal-fired power plants be allowed to do so without constraints. (J.K.)

[en] In this paper determination of dosimetric characteristics in a high energy radiation fields are described. The results obtained relatively to the tissue equivalent proportional counters are presented.The threshold values of an individual dosemeters were tested

[en] This report presents the results from measurements of aerosols of samples collected on the Measuring Points of Air Contamination. The activity concentrations of ¹³⁷Cs and ⁷Be in air during years 1993-1996 and the annual committed effective doses due to inhalation are summarized. During that period the concentrations of ¹³⁷Cs in air varied between 0.4 and 13.8 μBq m^-3. The annual committed effective doses due to inhalation of ¹³⁷Cs in air, according to the age, varied between 0.02 and 0.22 nSv from March 1993 through December 1996. During that period the concentrations of ^Be in air varied between 1.0 and 7.7 mBq m^-3 with an annual average of 2.8 mBq m^-3. Highest concentrations of ⁷Be in air were usually noted during the summer period. The annual committed effective doses due to inhalation of ⁷Be in air varied, according to age, from 1.1 to 1.8 nSv. (authors)

[en] In 1997 our laboratory organized intercomparison measurement in gamma spectrometry. The soil samples were delivered to 20 laboratories in 4 countries. The main aim was check the laboratory practice of member of the Slovak Radiation Monitoring Network. This summary contains the results of the intercomparison on the determination of radionuclides in soil by gamma spectrometry. The soil was collected in autumn 1996 near Namestovo (Orava region) from layer 0 -5 cm. Although data on 20 radionuclides were received, only data for ¹³⁴Cs, ¹³⁷Cs, ²²⁶Ra, ²²⁶Ra, ²³²Th and ⁴⁰K were statistically evaluated. The received activities are (mean activity, [Bq/kg]; standard deviation, [Bq/kg]; range [Bq/kg]): for ¹³⁴Cs: 1.05, 0.36, .0.31-1.85; for ¹³⁷Cs: 59.7, 1.6, 57.5-62.7; for ²²⁶Ra: 24.0, 1.5, 21.8-26.9; for ²³²Th: 27.3, 2.8, 22.4-33.1; for ⁴⁰K: 411, 39, 346-480. The used half-times and yields do not differ significantly. The differences between laboratories in reported results are due to mainly by sample treatment and spectra evaluation (used efficiency)

[en] The aims of this paper was: using radioactive indicator ⁶⁰Co to determine the speed of permeation of Co²⁺ across the skin depending on concentration of Co²⁺ in donor vehicle; to research the dominant routes of radionuclide permeation (intercellular, trans-cellular or appendageal; to assess the time profiles of Co²⁺ penetration across the skin. It was concluded that: the permeated fractions are the higher the lower is the concentration of Co²⁺ in donor solution; the permeated amounts of Co²⁺ are proportional to the concentration of these ions in donor vehicle; the dominant route of Co²⁺ penetration is along the follicles; it was proved that the principal penetration skin barrier for Co²⁺ is the upper layer. (authors)

[en] In this paper the results of monitoring of radon exposure in Slovakia by passive solid state nuclear track detectors (SSNTD ) (placed in about 6,000 selected dwellings, 1000 selected buildings of the kindergartens and basic schools, 12 selected spa buildings) and personal doses measured by SSNTD (130 miners from three ore mines and 13 tourist guides from seven show karst caves) are presented. The national survey results suggest that Slovak Republic may be among the countries with higher radon risk in Central Europe. The annual effective dose from indoor radon exposure is 2.1 mSv per inhabitants. The district with highest indoor radon concentrations and districts with high radon levels in spa buildings correlate with known presence of uranium in the soil. The soil is probably the main source of radon in Slovak dwellings, spa and school buildings too

[en] Our radon monitor was build at the Department of Nuclear Physics in the year 1992 till now it has been used for a continual monitoring of radon concentration in the outdoor atmosphere. The correctness of monitor measurements has been verified by series of radon pulses of different amplitude while the radon concentration in pulses has been determined by use of the scintillation cell of Lucas type. The obtainment of radon monitor Alpha Guard allows for a comparison of the operation of both monitors in real conditions. Our radon monitor is build on the basis of the large scintillation chamber. The inner diameter is 120 mm and its length is 200 mm. The volume of chamber is 4.5 liters. The inner space of the chamber is divided into 9 sectors to achieve good geometrical conditions for detection of radon. The walls of the sectors are coated by ZnS(Ag). Scintillations are collected through two glass windows placed at the ends of the chamber. At the flow rate of the air through the chamber of 0.5 l min^-1 and with an aerosol filter closely outside the chamber inlet the sensitivity of the scintillation chamber is 0.3 cpm at 1 Bw m^-3 of ²²²Rn concentration. The chamber background measured at the stable flow of the concentration of (8.3 ± 1.5) Bq m^-3. The monitor allows to obtain almost 80% of data of radon concentration in the outdoor atmosphere with an error less than 30%. A cylindric ionization chamber in a combination with DSP-technologies is used in Alpha Guard monitor (AG) for radon concentration measurement. The active volume of the ionization chamber is equal to 0.56 liters. In the diffusion mode of the operation the measured gas gets via a large surface glass fiber filter into the ionization chamber. The sensitivity of the detector is 0.05 cpm at 1 Bq m^-3 of ²²²Rn concentration. The background signal due to an internal detector contamination is less than 1 Bq m^-3. For the comparison of an operation of both radon concentration was measured in the same unventilated room. The results of tests show that the records of radon concentrations calculated on the basis of measured data are identical in the scope of counting errors. (authors)

[en] In this paper former legislation and current legislation for the quality assurance are compared. The State Office for Nuclear Safety in its regulatory activity in the QA area, reflected in the new legislation, is based on a gradual transition from a formal evaluation of quality assurance programmes to supervising activities to QA performance approach which means, besides other, that an appropriate responsibility for the quality of work is imposed on those persons who actually perform and supervise the work

[en] In the paper there are shown the results of measurement (by new developed method) from the ventilation stacks of NPP Dukovany and from ventilation stack of reactor in Nuclear Research Institute Rez in the time period 19996-1998. These results are compared with the results of similar former measurement from NPP Bohunice and from NPP Dukovany. This method can be recommended as a very useful independent method of monitoring of noble gases effluents from ventilation stacks of NPPs