[en] At the year 1998 the Standard of X radiation air kerma and dose equivalent and their rates of the Slovak Institute of Metrology was approved and declared as the national standard. From that time there were observed considerable progress of the measuring techniques and of the measurements, too. That reflected into the several upgrading of instrumentation of this standard and improvement of its metrological parameters. At 2004 was performed the revision of the national standard of air kerma,and dose equivalent of the X radiation and their rates and it was renamed to National standard of X radiation. There have been done the some modifications, upgrading and changing of the basic or auxiliary devices and of the measuring processes. All this modification, upgrading and changing brought the simplification and the improvement to the measurements, to the calibrations and to the tests made with utilisation of the national standard of X radiation. (author)

[en] Slovak Institute of Metrology is developing new metrology standard for high doses, based on the alanine-EPR as a reference dosimetry system. A Bruker e-scan EPR analyser developed specifically for alanine dosimetry has improved stability of EPR measurement, especially at lower dose range. The standard e-scan system provides sensitivity below 1 Gray. After further improvement of the system and lowering of dose determination expanded uncertainty down below 1 %, its utilisation for radiotherapy field is expected (authors)

[en] In this paper author deals with present effort in progress in question of small doses. Effects of small doses on organisms are discussed

[en] Selected radiation protection indicators of NPP Bohunice operation are published in poster - radioactive discharges to atmosphere and hydrosphere, personal doses, outage doses, maximum environmental doses. Limited parameters are also compared with authorized year limits. (authors)

[en] The purpose of this work was study the vertical distribution of ⁹⁰Sr and ¹³⁷Cs in uncultivated soils. The radionuclide contents in different soil layers and the cumulative deposition of radionuclides at the study sites were to be established with a view to possible identification of their sources. The present paper investigated the vertical distribution of ⁹⁰Sr and ¹³⁷Cs in uncultivated soil samples in central Bohemia and inventory of these radionuclides at representative sampling sites. These data provide the information about the availability, movement and environmental behaviour of these important radionuclides in the study region. The cumulative deposition of ⁹⁰Sr at sites 1, 2 and 3 were found of 700, 1390 and 970 Bq/m², respectively, The cumulative deposition of ¹³⁷Cs at sites 1, 2 and 3 were found of 260, 510 and 10000 Bq/m², respectively. The obtained values of ^9Sr are about 47% lower than the value of UNSCEAR inventories, but our average value of ¹³⁷Cs (3590 Bq/m²) agree with the cumulative deposition of ¹³⁷Cs from the atmospheric nuclear tests in northern 40 grad - 50 grad temperate zone according UNSCEAR inventories. The radioactive decay should have reduced the reported ⁹⁰Sr and ¹³⁷Cs inventories in the northern hemisphere to 2190 Bq/m² and 3580 Bq/m², respectively. The concentration of ⁹⁰Sr and ¹³⁷ Cs increased proportionally to the SOM content in soil, but the difference of the degree of correlation among ⁹⁰Sr and ¹³⁷CS could be explained by the fact that SOM held ¹³⁷Cs more strongly than ⁹⁰Sr. ¹³⁷Cs showed very low mobility in soil profiles in undisturbed soils, therefore, it was concentrated in the upper 10 cm of the soils. Although the concentration of ⁹⁰Sr increased with organic content through an anion exchange reaction, which is enhanced by SOM keeping high cationic exchange capacity, the retention of Sr was relatively weak in contrast to Cs. It is related with high mobility of Sr that is a member of group II in the periodic table and acts like Ca. The fact that the peak ⁹⁰Sr concentration usually could be found below 10 cm of the soil profile is a proof, whereas some 85% of the ¹³⁷Cs was found within 10 cm from the surface soil layers. It is well known that calcium plays an important role in the adsorption process. (authors)

[en] The publication has been set up as a proceedings of the conference dealing with health protection during work with ionizing radiation for different activities which involve the handling of ionizing radiation sources. The main conference topics are focused on current problems in radiation protection and radioecology. In this proceedings totally 83 papers are published

[en] In this work, the two-mutation model has been applied and compared with BEIR VI models for a prediction of the radon risk in various environments. The obtained results can be summarised into several points. The values of risk from the radon exposure predicted by the two-mutation model are comparable with the results obtained by BEIR VI for the short-time as well as for the long-time exposures. In the range of low exposures is this agreement of the results closer to the risk values assessed by the exposure-age-concentration model. In the range of higher exposures the results are closer to the values based on the age- duration model. The two-mutation model predicts the increase of dRR/dC with the increase of the radon concentration in the range of low concentrations. According to our results the inverse effect occurs only when the radon concentrations reach the value of 1500 Bq/m³. The two-mutation model can be taken as an universal model for the risk calculation in different environments, and for various smoking status. This model makes possible to analyse the influence of the fractionalisation of the exposure on the resulting RR. (authors)

[en] The ESTE system (Emergency Source Term Evaluation) is support instrument for off-site emergency response and its main objective is to assist to the crisis staff: - to mitigate radiological consequences of significant releases; - to manage the protective measures; - to manage emergency monitoring. At national level the ESTE system are implemented at the Emergency Response Centre of the Czech Republic (SUJB) and Austrian versions are implemented at the Crisis Centre of the Austrian Republic (BMLFUW). ESTE system can now be utilized not only in close (40 km) vicinity of the point of the release (NPP), but radiological impacts are now calculated across the whole country or over the country border. Puff Trajectory Model (PTM) with the background of geographical information system (GIS) is included in este. Numerical weather prediction data (wind fields) predicted for the whole or the part of the country are online connected with este and utilized for the puffs movement simulation and impacts calculations. It means that not only meteorological data from the point of release (measured or predicted), but 'meteorological data wind field' predicted for larger region across the country are used by the este system. (author)

[en] The aim of this study was to compare the amount of radiocaesium in chosen parts of food chains from localities in the Eastern Slovakia. Prevailing part of radiocaesium is in the upper layer of soils and specific activity of ¹³⁷Cs in the first layer for locality Stara Voda in 2000 achieved 152.4 Bq/kg¹. On the base of results from modified Tessier sequential extraction method we determined that more than 50 % of this radionuclide is in the soil in not extractable fraction. From studied species of mushrooms the highest value was determined in sample of Rozites caperata the and specific activity achieved 1822.0 Bq/kg¹ d. w. The aim of our study was to determine the amount of caesium in chosen parts of food chains from localities in Eastern Slovakia for period 2000-2004. On the base of obtained results we can conclude that radiocaesium migrates vertically in soils very slowly and prevailing part of caesium is in the upper layer. Prevailing part of radiocaesium is in the not extractable fraction. Extremely low concentration of caesium in soil solution is the factor limiting caesium uptake by the root systems, too. Mushrooms are characterised by high ability to accumulate radiocaesium. (authors)

[en] Illicit trafficking in nuclear materials (nuclear criminality) has become a problem, due to the circulation of a high number of radioactive sources caused by the changes of the organisational infrastructures to supervise these material within the successor states of the former Soviet Union. Aim of this paper is to point out the technical requirements and the practicability of an useful monitoring system at preselected traffic check points (railway and highway border crossings, industrial sites entry gates, international airports). The ITRAP lab test was designed to work as strict benchmark to qualify border monitoring systems 67 with very low false alarm rates, in addition the minimum sensitivity to give an alarm has been defined for fix-installed systems, pocket type and hand held instruments. For the neutron tests a special prepared Californium source (²⁵²Cf) was used to simulate the weapons plutonium. The source is shielded against gamma radiation, use a moderator and provides the required neutron rate of 20000 n/s at 2^rn distance. To test the false alarm rate (rate of false positive ) the same test facility , under the same background conditions, was used but without a radioactive test source. The ITRAP lab tests for the fix-installed systems started at May 1998 and first results were given in September 1998. Only 2 of 14 fix-installed monitoring systems could fulfil the minimum requirement for neutron detection. 7 of 14 fix-installed monitoring systems (50%) passed the ITRAP lab test. The analytical method developed and used for certification of installed radiation monitors in the Slovak Institute of Metrology consists in measurement of radiation activity of selected radionuclide in defined conditions. (authors)