Vpliv sončne aktivnosti na okoljski dozni ekvivalent H*(10) v Sloveniji merjen s termoluminiscenčnimi dozimetri

Ambient dose equivalent H*(10) is measured to assess general population exposure to ionising radiation. From its spatial and time variations it is possible to identify sources of exposure. In Slovenia, semi-annual H*(10) is measured routinely with thermoluminescence dosimeters at 66 locations around the Nuclear Power Plant (NPP) Krško and at 50 other locations covering the rest of Slovenian territory. Since the Chernobyl accident contamination had ceased to contribute to ambient dose equivalents, we have been calculating correlation coefficients between annual mean number of sunspots and annual H*(10). These correlation coefficients were calculated for five locations in western Slovenia and for five annual H*(10) extracted from measurements around NPP Krško. Their ranges between –0.64 and –0.38 suggest a clear negative correlation between solar activity and H*(10). Mean annual H*(10) averted by solar activity in the past two solar maxima reached 0.070 mSv around NPP Krško (155 m.a.s.l.) and 0.132 mSv and 0.180 mSv at Kredarica (2515 m.a.s.l.). Quantifying the influence of the solar activity on the ambient dose equivalent helps us to better understand exposure of the general population to ionising radiation.Okoljski dozni ekvivalent H*(10) merimo, da ocenimo izpostavljenost populacije ionizirajočemu sevanju. Iz časovne in prostorske odvisnosti je mogoče ugotoviti vire izpostavljenosti. Polletne dozne ekvivalente H*(10) merimo rutinsko s termoluminiscenčmimi dozimetri na 66 lokacijah v okolici Jedrske elektrarne Krško (NEK) in na 50 drugih lokacijah na teritoriju Slovenije. Ker kontaminacija zaradi Černobilske nesreče ne prispeva več k okoljskemu doznemu ekvivalentu smo izračunali korelacijske koeficiente med povprečnim letnim številom sončnih peg in letnim H*(10). Korelacijske koeficiente smo izračunali za pet lokacij v Zahodni Sloveniji in pet lokacij v bližini NEK. Vrednosti korelacijskih koeficientov so v intervalu od -0.64 do -0.38, kar kaže na močno korelacijo med sončno aktivnostjo in H*(10). Zaradi sončeve aktivnosti so bili povprečni letni H*(10) v zadnjih dveh sončnih maksimumih zmanjšani za 0.070 mSv v okolici NEK (na nadmorski višini 155 m) in za 0.132 mSv in 0.180 mSv na Kredarici (na nadmorski višini 2515 m). Ovrednotenje vpliva sončeve aktivnosti na okoljski dozni ekvivalent boljša razumevanje izpostavljenosti populacije ionizirajočemu sevanju

Behaviour of beryllium-7 and lead-210 time series measured in Serbia and Slovenia over 1991-2015

6th International Conference on Radiation and Applications in Various Fields of Research (RAD), Book of Abstracts, Jun 18-22, 2018, Ohrid, Macedoni

Comparison of concentration activities of ruthenium isotopes measured over Slovenia and Serbia

6th International Conference on Radiation and Applications in Various Fields of Research (RAD), Book of Abstracts, Jun 18-22, 2018, Ohrid, Macedoni

Interlaboratory comparison on 137Cs activity concentration in fume dust

Proceeding of the 9th International Topical Meeting on Industrial Radiation and Radioisotope Measurement Applications, 6-7 July 2014, Valencia, Spain.; International audience; A comparison was conducted, between 11 European National Metrology Institutes and EC-JRC, on measurement of Cs-137 activity concentration in fume dust. As test material an activity standard produced from real contaminated fume dust was used. The standard material consisted of 13 cylindrical samples of compressed fume dust. The material contained Cs-137 and Co-60 of reference activity concentrations of (9.72 +/- 0.10) Bq/g and (0.450 +/- 0.018) Bq/g, respectively, for the reference date of 1 June 2013, determined using the comparison results. The organization and results of the intercomparison, as well as the process of obtaining reliable reference values are presented

Factor analysis of the beryllium-7 and lead-210 specific activities in surface air, and meteorological parameters

Međusobna povezanost specifičnih aktivnosti berilijuma-7 i olova-210 u prizemnom sloju atmosfere sa meteorološkim parametrima razmotrena je u faktorskoj analizi. Merenja su sprovedena u Beogradu, Republika Srbija, i u Ljubljani i Krškom, u Republici Sloveniji, tokom 1991–2015 godine. Na sve tri lokacije, faktorska opterećenja dva faktora pokazuju da je: 1) specifična aktivnost berilijuma-7 obuhvaćena faktorom 1 sa temperaturom, oblačnošću i relativnom vlažnošću; dok je 2) specifična aktivnost olova-210 obuhvaćena faktorom 2 sa količinom padavina i atmosferskim pritiskom. Iako je komunalitet već dva faktora veći od 0,5 za većinu posmatranih varijabli, tek uvođenjem trećeg faktora komunalitet za specifičnu aktivnost olova-210 i atmosferskog pritiska na sve tri merne lokacije raste na preko 0,5. Rezultati faktorske analize pokazuju da se specifične aktivnosti berilijuma-7 i olova-210 u prizmenom sloju atmosfere nalaze pod različitim dominantnim uticajima. Koncentracija berilijuma-7 je pod uticajem faktora regionalnog karaktera, koji je takođe dominantan za srednju temperaturu. Ova veza specifične aktivnosti berilijuma-7 i temperature preko dominantnog zajedničkog faktora važi i kada se broj faktora u analizi poveća na tri i četiri. Sa druge strane, na koncentraciju olova-210, kao i na količinu padavina i atmosferski pritisak, više uticaja ima lokalni faktor. Ova povezanost olova-210 sa druga dva meteorološka parametra, međutim, prestaje da važi sa povećanjem broja faktora u analizi na tri, kada se izdvaja specifičan faktor koji objašnjava preko 80% varijanse specifične aktivnosti olova-210.An association between the beryllium-7 and lead-210 specific activities in surface air and meteorological parameters is investigated using factor analysis. The measurements were conducted in Belgrade, Republic of Serbia, and Ljubljana and Krško, Republic of Slovenia, over 1991–2015. In all the locations, the factor loadings of two factors show that: 1) the beryllium-7 specific activity is encompassed by factor 1 together with temperature, cloud cover and relative humidity; while 2) the lead-210 specific activity, precipitation and atmospheric pressure are described by factor 2. Although the communalities of only two factors are already larger than 0.5 for most of the variables, an introduction of a third factor raises the communalities of all the variables above 0.5. The results imply that the beryllium-7 and lead-210 are under different dominant underlying mechanisms. The concentration of beryllium-7 seems to be primarily influenced by a mechanism of a regional character which is also a predominant factor for temperature. This association between the beryllium-7 specific activity and temperature prevails even when the number of factors in the analysis is raised to three and four. The lead-210 specific activity, on the other hand, together with precipitation and atmospheric pressure, is under an influence of a local mechanism, but that relationship between the variables ceases to hold when the number of factors is raised to three, and more than 80% of the variance in the Pb-210 specific activity is explained by one specific factor.Article is part of: [http://vinar.vin.bg.ac.rs/handle/123456789/8245

Beryllium-7 activity concentration trends in Serbia and Slovenia

Beryllium-7 is a natural radionuclide used as a tracer of the stratospheric-tropospheric exchange. Its abundance in the surface air is expected to change as the temperatures in the atmosphere increase. To investigate the temporal trends of the beryllium-7 activity concentrations and temperature, we apply spectral analysis to time series from three sampling sites: Belgrade in Serbia, and Ljubljana and Krško in Slovenia. The sites lie close to the 45 ºN parallel, with Krško approximately 400 km and Ljubljana around 500 km west of Belgrade. Between January 1991 and December 2019, the air filter samples were collected using air samplers; a monthly composite sample was formed and analysed by gamma spectrometry. We use monthly mean temperature records from the European Climate Assessment & Dataset, the Republic Hydrometeorological Service of Serbia for Belgrade, and the Slovenian Environment Agency for the sites in Slovenia. In the spectral analysis decomposition, we look into a term called trend that represents the overall growth (increase or decrease) in the data records. The trend is calculated using a linear fit. All three sites show 1) positive temperature trends, however statistically insignificant (at the 95 % confidence level), and 2) statistically significant beryllium-7 activity concentration trends of 2.26 %/year, 1.13 %/year, and 0.50 %/year in Belgrade, Ljubljana, and Krško, respectively. The results confirm our initial hypothesis–over the 28 investigated years, the beryllium-7 activity concentrations increase in the surface air. On the other hand, the non-significant temperature rise in our records suggests that within our method, the temporal resolution of one month is insufficient for obtaining a statistically significant temperature trend

60Co in Cast Steel Matrix: a European Interlaboratory Comparison for the Characterisation of New Activity Standards for Calibration of Gamma-ray Spectrometers in Metallurgy

International audience; Two series of activity standards of Co-60 in cast steel matrix, developed for the calibration of gamma-ray spectrometry systems in the metallurgical sector, were characterised using a European interlaboratory comparison among twelve National Metrology Institutes and one international organisation. The first standard, consisting of 14 disc shaped samples, was cast from steel contaminated during production ("originally"), and the second, consisting of 15 similar discs, from artificially-contaminated ("spiked") steel. The reference activity concentrations of Co-60 in the cast steel standards were (1.077 +/- 0.019) Bq g(-1) on 1 January 2013 12h00 UT and (1.483 +/- 0.022) Bq g(-1) on 1 June 2013 12h00 UT, respectively

GRAMON Database: Ten Years of Beryllium-7 Specific Activity Measurements

U radu je predstavljena novoformirana baza podataka GRAMON (Ground Air Radioactivity Monitoring) koja sadrži rezultate merenja radioaktivnosti u vazduhu na sedam lokacija: Beograd (Srbija), Ljubljana i Krško (Slovenija), Sarajevo (Bosna i Hercegovina), Podgorica (Crna Gora), Skoplje i Bitola (Severna Makedonija). Iz baze su za sve lokacije preuzete mesečne vrednosti specifične aktivnosti prirodnog radionuklida berilijuma-7 i potom analizirani deskriptivni statistički parametri od januara 2010. do decembra 2019. godine. Srednje vrednosti specifične aktivnosti berilijuma-7 tokom ovog perioda kreću se od 3,32 mBq/m3 u Sarajevu do 5,93 mBq/m3 u Beogradu. Koeficijent varijacije najmanji je za Krško (37,7%) i Sarajevo (38,6%), a najveći za Beograd (54,8%) i Bitolu (72,4%). Ipak, 3σ-opsezi svih sedam vremenskih serija se preklapaju. U daljoj statističkoj analizi biće ispitano da li među ovim vremenskim serijama postoje značajne razlike.This paper presents a recently established Ground Air Radioactivity Monitoring (GRAMON) database that contains the results of radioactivity measurements in the air at seven locations: Belgrade (Serbia), Ljubljana and Krško (Slovenia), Sarajevo (Bosnia and Herzegovina), Podgorica (Montenegro), Skopje and Bitola (North Macedonia). Monthly values of specific activity of the natural radionuclide beryllium-7 were selected from the database and descriptive statistical parameters were analyzed for each location from January 2010 to December 2019. The mean values of the specific activity of beryllium-7 over this period range from 3.32 mBq/m3 in Sarajevo to 5.93 mBq/m3 in Belgrade. The coefficient of variation is the least for Krško (37.7%) and Sarajevo (38.6%), and the largest for Belgrade (54.8%) and Bitola (72.4%). Still, the 3σ-intervals of all seven time series overlap. Further statistical analysis will investigate whether there are any significant differences among these time series.XXXII Simpozijum Društva za zaštitu od zračenja Srbije i Crne Gore, 4-6. oktobar 2023; Budva, Crna GoraProceedings: [https://vinar.vin.bg.ac.rs/handle/123456789/11602

Introducing a regional database of radioactivity in the air – GRAMON

Ground Air Radioactivity Monitoring (GRAMON) database is a recently established collection containing activity concentrations of gamma emitters in aerosol samples. The measurements come from Serbia (sampling site Belgrade), Slovenia (sampling sites Ljubljana and Krško), Bosnia and Herzegovina (sampling site Sarajevo), Montenegro (sampling site Podgorica), and North Macedonia (sampling sites Skopje and Bitola), thus covering the northern and central parts of the Balkan Peninsula. As a database arising from the monitoring programmes in several countries, GRAMON is not fully homogeneous in terms of the radionuclides and time periods studied. For example, the beryllium-7 records are available for all sampling sites, while the lead-210 records only in Serbia, Slovenia, and Bosnia and Herzegovina. The time series for Serbia and Slovenia began in 1991, for Montenegro and North Macedonia in 2008, and for Bosnia and Herzegovina in 2010. However, sampling, sample preparation, and measurement procedures across the sites and laboratories are similar. In brief, aerosol samples are collected on filter papers using air samplers. Activity concentrations of radionuclides are determined by standard gamma spectrometry using high-purity germanium detectors. The time series contain monthly mean activity concentrations. Since only some of the GRAMON records have been previously published, this database provides a source for radioactivity research in the region that has been underrepresented in large-scale studies. We further hope to expand the number of contributing laboratories and cover a wider region of Europe, especially its southern and eastern parts.Book of abstract

Analysis of HPGe Spectra by Spectrum Matching - Experimental Verification

A new approach to spectrum analysis in gamma-ray spectrometry has recently been proposed. The approach is based on full, channel-by-channel matching of the measured spectrum with calculated synthetic spectra. These are created for each of the radionuclides in a context-sensitive radionuclide library and contain the peaks that would appear in the measured spectrum if the radionuclide were present in the sample. The input required for their synthesis consists of the full-energy-peak efficiency curve, the emission probabilities of the individual gamma rays and the corresponding coincidence summing correction factors. Also required are the suitably parameterized energy and peak-shape calibration curves. A search is made for the linear combination of these single-radionuclide spectra that matches the measured spectrum best, and the resulting coefficients in this combination are the desired activities of the radionuclides in the sample. In the optimization process, the parameters of the energy calibration and peak-shape curves are also determined. To avoid the need for modeling the background below the peaks in the spectra smoothed first derivatives of both the measured spectrum and the synthetic spectra are used, rather than their original shapes. In the paper, verification of the new method against experimental data is presented.JRC.D.5-Neutron physic