Improvement of measuring methods and instrumentation concerning (222)Rn determination in drinking waters - RAD7 and LSC technique comparison.

A procedure for the determination of (222)Rn in environmental water samples using liquid scintillation counting (LSC) was applied and optimized. A minimum detectable activity of 0.029Bql(-1) in a 20ml glass vial (10ml water sample mixed with 10ml of liquid scintillation cocktail) has been achieved during 300min of measurement time. The procedure was compared with RAD7 radon detector measurements. (226)Ra content in the water was determined by gamma-ray spectroscopy. Applications to drinking waters collected from public drinking fountains in the Vojvodina (Serbia) are presented with annual effective dose for ingestion and inhalation for adults calculated.

Establishment of a method for ²²²Rn determination in water by low-level liquid scintillation counter.

A procedure for the determination of (222)Rn in environmental water samples using liquid scintillation counting (LSC) was performed. The (226)Ra content in the water was determined by gamma-ray spectroscopy. An application of this procedure to drinking water collected from a public drinking fountain in Vojvodina (Serbia) is presented, including calculations of the annual effective dose for ingestion and inhalation for adults.

Radioactivity in the indoor building environment in Serbia.

Measurement of activity concentrations of radionuclides in building materials and radon in indoor space is important in the assessment of population exposures, as most individuals spend 80 % of their time indoors. This paper presents the results of activity concentration measurements of: radon emanated from the soil, radionuclides (226)Ra, (232)Th and (40)K in the soil, indoor radon in the city of Novi Sad (the capital city of Vojvodina) using charcoal canisters and indoor radon in the Vojvodina region using alpha-track detectors and the radioactivity of some building materials. Influences of floor level, space under the rooms, boarding, and the heating system on indoor radon accumulation in the Vojvodina province, situated in the northern part of Serbia, are also presented in this paper. The total effective dose and the activity concentration index are calculated applying the dose criteria recommended by the European Union for building materials.

Different methods for tritium determination in surface water by LSC.

The main aim of this paper was to compare different methods of preparing water samples for tritium analysis by ultra-low-level background liquid scintillation counter, Quantulus 1220. Three methods of sample preparation for low-level tritium measurement have been implemented in the Nuclear Physics Laboratory in Novi Sad: electrolytic enrichment, direct method without electrolytic enrichment and sample Oxidizer 307 method. The examined fresh water samples were rainfall collected during 6 months and water from a stream in the Vinca nuclear research center collected over 3 months. The obtained results using these three methods showed satisfying agreement. The appropriate measuring time by LSC for each sample prepared according to different methods has been determined.

Airborne radioiodine in northern Serbia from Fukushima.

The results obtained with the monitoring system set up to assess the impact of the Fukushima accident on the environment of Vojvodina (Northern Province of Serbia) are presented and discussed. Aerosol, rain, fresh milk and spinach samples were collected daily in the weeks following the accident. In the aerosol samples, (131)I activity concentrations of several mBq m(-3) were measured, while in rain, milk and spinach samples, (131)I levels had values in a range of (0.3-1.7) Bq kg(-1). These are the first results on the impact of the Fukushima accident on the Pannonian basin region. Our results are compared with the reported values from other parts of the world.

Public exposure to radon in drinking water in Serbia.

Radon is the main source of natural radiation that is received by population. The results of radon activity measurements in water from public drinking fountain, from bottled drinking water and from tap water in the city of Novi Sad, Serbia, are presented in this paper. The measurements were performed by RAD 7 radon detector manufactured by DURRIDGE COMPANY Inc. The corrected value of radon concentration in one sample exceeded the European Commission recommendation reference level for radon in drinking water of 100 Bql(-1). In order to make the correlation between radon and radium concentrations in the tap water and in the water from public drinking fountain, the gamma-spectrometric measurements were performed. The results of (222)Rn activity concentration measurements from soil in the city of Novi Sad using RAD 7 detector are presented.

Monitoring for exposures to TENORM sources in Vojvodina region.

TENORM are found in a wide variety of waste materials, some raw mineral ores and in some consumer products (in trace amounts) where molecules of radionuclides may be bound to specific minerals used in the manufacturing process and can result in increases in radiation exposures to workers and the public. The aim of this paper is to understand this problem and to develop effective ways to protect humans and the environment from harmful exposure to the radiation in TENORM materials in the Vojvodina region. The results of measurement of indoor radon concentration in schools and kindergartens and dose-rate and gamma-spectrometry measurements of the workplace with TENORM materials are presented.

Search for TENORM in the Tisza River sediment.

Sediment samples from the Tisza River in Serbia were investigated for possible TENORM pollutants. The radionuclide content of the samples was determined by means of low-level high-resolution gamma-spectroscopy. In addition to the members of the natural radioactive chains of (238)U and (232)Th and the natural (40)K, Chernobyl origin (137)Cs was detected in 26 of the 28 samples tested. The higher concentration of (238)U in four locations along the river could be caused by extensive exploitation of phosphate fertilizers in the surrounding agricultural area (TENORM). Also, in one location the lowest (40)K and the highest (232)Th concentration in all samples were detected. Every unexpected distribution is an indication of radioactive contamination.