Pu-239+240 and Pu-238 in soils of Montenegro - origin and activity concentrations

Mjerenja koncentracija aktivnosti 239+240Pu i 238Pu u uzorcima zemljišta iz Crne Gore vršena su u Minsku (BelGIM) i u Helsinkiju (STUK), utvrđeni su njihovi međusobni odnosi, kao i odnosi koncentracija plutonijumovih izotopa i 137Cs. Na osnovu toga je diskutovano i njihovo porijeklo, a na osnovu aktivnosti 137Cs izmjerenih na teritoriji Crne Gore na 91 lokaciji (67 – samo površinski sloj, 24 – slojevi: 0-5 cm, 5-10 cm i 10-15 cm) procijenjeni su i u ovom radu predstavljeni nivoi aktivnosti Pu izotopa.The measurements of 239+240Pu and 238Pu activity concentration in soil samples from Montenegro, together with 137Cs activity measurements in the same samples, were used to determine the activity ratios enabling a discussion about origin of these radionuclides, as well as estimating Pu isotopes level in soils at the territory of Montenegro. The 239+240Pu/137Cs activity ratio was found to be with an average of 0.020 and standard deviation of 0.007, the 238Pu/137Cs – with an average of 0.0006 and standard deviation of 0.0003, the 238Pu/239+240Pu – with an average of 0.030 and standard deviation of 0.007, confirming that plutonium isotopes, today present at the territory of Montenegro, originated from the global fallout. These, as well as the other results showed that 137Cs today present at the territory of Montenegro predominantly has the Chernobyl’s origin. Based on 137Cs activity concentrations in the Montenegro soils measured in the period 1994-2011, using in situ and standard laboratory HPGe spectrometric method, levels of soil contamination with plutonium isotopes have been evaluated and discussed – for 91 locations (67 – surface soil only, 24 – layers: (0-5) cm, (5-10) cm and (10-15) cm). The highest measured 137Cs activity in top soils in 1994 was 740 Bq/kg, in 2001 – 1710 Bq/kg, in 2002 – 2011 Bq/kg, in 2011 – 413 Bq/kg, while the highest estimated (and measured) 239+240Pu in 2011 – 8.3 Bq/kg.Article is part of: [http://vinar.vin.bg.ac.rs/handle/123456789/8230

137Cs у животној средини Црне Горе (од 1999. године)

Kvar u nuklearnoj elektrani u Černobilju 1986. godine proizveo je nuklearnu katastrofu ogromnih razmjera, sa tragičnim posljedicama za ljude i živi svijet u široj okolini elektrane i radioaktivnom kontaminacijom životne sredine na ogromnim prostorima naše planete, koja još uvijek nije isčezla. Stoga je ova katastrofa u javnosti izazvala strah od nuklearne tehnologije, pa je javnost i koristi kao simbol opasnosti koja svijetu prijeti od nuklearki. Prva brojna mjerenja nivoa radioaktivne kontaminacije životne sredine u Crnoj Gori počela su neposredno poslije akcidenta. Međutim, tek od 1999. godine u Crnoj Gori se, kroz Program monitoringa radioaktivnosti u životnoj sredini, realizuje sistematsko i redovno ispitivanje sadržaja radionuklida u vazduhu, padavinama, površinskim vodama, morskoj vodi, zemljištu, hrani i vodi za piće. U radu je dat presjek stanja sadržaja 137Cs u većini segmenata životne sredine Crne Gore, a takođe i prikaz trendova, kao i nekih specifičnih slučajeva i pojava. Indikativno je da se u manjem broju slučajeva, čak i 30 godina nakon černobiljskog akcidenta, pojavljuje relativno visok sadržaj 137Cs u mesu, niži ali ipak izražen u mlijeku, dok je sadržaj u zemljištu mjestimično na nivou neznatno nižem od prvobitno utvrđenog krajem 90-ih godina. Sve ovo upućuje na opravdanost dalje realizacije Programa monitoringa radioaktivnosti u sistematskom praćenju stanja životne sredine.Malfunction in Chernobyl nuclear power plant in 1986 produced a nuclear disaster of major proportions, with tragic consequences for the people and wildlife in wider area of power plant and radioactive contamination of the environment in the vast spaces of our planet, which has not yet disappeared. Therefore, this catastrophe has caused public fear from nuclear technology, and the public use it as a symbol of danger that threatens the world from nuclear power plants. The first numerous measurements of the level of radioactive contamination of the environment in Montenegro began immediately after the accident. However, only since 1999 in Montenegro, through the program of monitoring radioactivity in the environment, is being implemented a systematic and regular monitoring of the content of radionuclide’s in the air, precipitation, surface water, sea water, soil, food and drinking water. The paper gives cross-section of 137Cs content in most segments of the environment of Montenegro, and also presentation of trends, as well as some specific cases. It is indicative that in a minority of cases, even 30 years after the Chernobyl fallout, appears relatively high content of 137Cs in meat, lower but still expressed in milk, while the content in the soil in some places on level slightly lower than the originally established at the end of the 90s. All this justifies the further realization of the Program of radioactivity monitoring in the systematic monitoring of the environment.Article is part of: [http://vinar.vin.bg.ac.rs/handle/123456789/8230

137Cs у животној средини Црне Горе (од 1999. године)

Kvar u nuklearnoj elektrani u Černobilju 1986. godine proizveo je nuklearnu katastrofu ogromnih razmjera, sa tragičnim posljedicama za ljude i živi svijet u široj okolini elektrane i radioaktivnom kontaminacijom životne sredine na ogromnim prostorima naše planete, koja još uvijek nije isčezla. Stoga je ova katastrofa u javnosti izazvala strah od nuklearne tehnologije, pa je javnost i koristi kao simbol opasnosti koja svijetu prijeti od nuklearki. Prva brojna mjerenja nivoa radioaktivne kontaminacije životne sredine u Crnoj Gori počela su neposredno poslije akcidenta. Međutim, tek od 1999. godine u Crnoj Gori se, kroz Program monitoringa radioaktivnosti u životnoj sredini, realizuje sistematsko i redovno ispitivanje sadržaja radionuklida u vazduhu, padavinama, površinskim vodama, morskoj vodi, zemljištu, hrani i vodi za piće. U radu je dat presjek stanja sadržaja 137Cs u većini segmenata životne sredine Crne Gore, a takođe i prikaz trendova, kao i nekih specifičnih slučajeva i pojava. Indikativno je da se u manjem broju slučajeva, čak i 30 godina nakon černobiljskog akcidenta, pojavljuje relativno visok sadržaj 137Cs u mesu, niži ali ipak izražen u mlijeku, dok je sadržaj u zemljištu mjestimično na nivou neznatno nižem od prvobitno utvrđenog krajem 90-ih godina. Sve ovo upućuje na opravdanost dalje realizacije Programa monitoringa radioaktivnosti u sistematskom praćenju stanja životne sredine.Malfunction in Chernobyl nuclear power plant in 1986 produced a nuclear disaster of major proportions, with tragic consequences for the people and wildlife in wider area of power plant and radioactive contamination of the environment in the vast spaces of our planet, which has not yet disappeared. Therefore, this catastrophe has caused public fear from nuclear technology, and the public use it as a symbol of danger that threatens the world from nuclear power plants. The first numerous measurements of the level of radioactive contamination of the environment in Montenegro began immediately after the accident. However, only since 1999 in Montenegro, through the program of monitoring radioactivity in the environment, is being implemented a systematic and regular monitoring of the content of radionuclide’s in the air, precipitation, surface water, sea water, soil, food and drinking water. The paper gives cross-section of 137Cs content in most segments of the environment of Montenegro, and also presentation of trends, as well as some specific cases. It is indicative that in a minority of cases, even 30 years after the Chernobyl fallout, appears relatively high content of 137Cs in meat, lower but still expressed in milk, while the content in the soil in some places on level slightly lower than the originally established at the end of the 90s. All this justifies the further realization of the Program of radioactivity monitoring in the systematic monitoring of the environment.Article is part of: [http://vinar.vin.bg.ac.rs/handle/123456789/8230

Calibration of recycled open-faced charcoal canisters for two- and one-day radon concentration measurements

Charcoal canisters have been used for indoor radon concentration measurements for more than 40 years. Although there are several methods that use charcoal canisters, the basic principle is the same. As air passes through the canister, radon is being adsorbed and the quantity of adsorbed radon is proportional to the radon concentration in air. Radon canisters can be modified in different ways, e.g. by adding diffusion barriers, and different techniques can be used for counting. The method used in Vinča Institute of Nuclear Sciences (VINS) uses open-faced canisters, which are measured on gamma spectrometers, according to US EPA method. In this method, it is necessary to wait 3 hours after closing the canisters in order to reach equilibrium, because radon is determined via gamma emissions of radon progeny - 214Pb and 214Bi. Canisters are commonly exposed for periods between 48 hours and 144 hours. Open faced radon canisters are typically used with calibration factors provided by manufacturers, or with EPA calibration factors. Calibration in EPA method is performed with canisters as received from manufacturers, but most laboratories recycle canisters by drying in order to reuse them. Since calibration factor is calculated based on the canister mass change (due to water adsorption) and duration of exposure, different moisture content due to recycling may introduce a bias in the measurement. A correction for this influence might be necessary. In order to investigate this effect, recycled canisters used in VINS have been exposed to different radon concentrations in a radon calibration chamber in Montenegro Bureau of Metrology. Exposures lasted for 48 h and the results have been used to assess the validity of used calibration factors. Additional measurements lasting (24±2) h have been performed at several selected measurement locations, covering two orders of magnitude of concentrations. Simultaneously, concentrations were measured with an AlphaGUARD detector, which was used as a reference instrument. This experiment allowed determination of calibration factor for short term measurements lasting 1 day. It is, however, necessary to perform additional study of uncertainty before using charcoal canisters for one-day measurements.VIII International Conference on Radiation in Various Fields of Research : RAD 2020 : book of abstracts; Virtual Conferenc

Radon indoor survey in Montenegro

Sistematsko istraživanje radona u stalno nastanjenim stanovima u Crnoj Gori završeno je krajem 2016. godine. Mjerenja radona su rađena detektorima tragova CR-39, u trajanju dva puta po 6 mjeseci. Dobijeno je da je srednja godišnja koncentracija aktivnosti radona u stanovima u Crnoj Gori 110 Bq/m3 , a medijana 52 Bq/m3 . Prosječne godišnje koncentracije aktivnosti radona u stanovima po opštinama kreću se od 40 Bq/m3 (Budva) do 201 Bq/m3 (Nikšić). U kvadratima mreže 10 km x 10 km, koja prekriva teritoriju države, prosječne godišnje koncentracije aktivnosti radona u stanovima su u opsegu od 30 Bq/m3 do 732 Bq/m3 . Srednja godišnja koncentracija aktivnosti radona u stanovima urbanih područja (86 Bq/m3 ) znatno je manja od one u stanovima ruralnih područja (144 Bq/m3 ). Takođe, srednja godišnja koncentracija aktivnosti radona u kolektivnim stambenim zgradama (51 Bq/m3 ) više nego dvostruko je manja od one u individualnim porodičnim kućama (119 Bq/m3 ).First systematic national radon survey in 1095 dwellings in Montenegro was finished by the end of year 2016. Radon was measured with CR-39 nuclear track detectors during two consecutive six-month periods. It is obtained that the national average radon activity concentration in indoor air of homes in Montenegro is 110 Bq/m3 and median is 52 Bq/m3 . The average indoor radon concentrations in the municipalities are in range from 40 Bq/m3 (Budva municipality) to 201 Bq/m3 (Niksic municipality). The average radon concentrations are also calculated for each of 131 squares of the 10 km × 10 km grid which covers territory of Montenegro, and they are in a range from 30 Bq/m3 to 732 Bq/m3 . In rural areas, the average indoor radon concentration (144 Bq/m3 ) is much higher than the corresponding one in urban areas (86 Bq/m3 ). Also, the average radon activity concentration in the single-family detached houses (119 Bq/m3 ) are more than twice higher than in dwellings of the large apartment buildings (51 Bq/m3 )

Radon Equilibrium Factor in Selected Dwellings and Workplaces in Montenegro and Serbia

U radu su prikazani rezultati merenja radonskog ravnotežnog faktora aktivnom metodom na 5 lokacija u Crnoj Gori i Srbiji. Dobijeni rezultati su u rasponu od 0.36 do 0.7, što je u proseku veće od preporučene vrednosti od 0.4. Na istim lokacijama su izvršena interkomparativna merenja koncentracije radona (uređajima Alpha Guard Pro, RAD7 i RTM1688-2), ravnotežne ekvivalentne koncentracije radona (uređajima RNWL i RPM2200) i radonskog ravnotežnog faktora. Slaganje rezultata je testirano Z-testom koji ukazuje da ne postoji statistički značajno odstupanje između rezultata dobijenih različitim mernim uređajima, odnosno ne postoji nekonzistentnost između različitih metodologija merenja kao ni potrebe za harmonizacijom različitih procedura merenja.In this contribution, the results of radon equilibrium factor measurement in selected dwelling and workplaces in Montenegro and Serbia are presented. Radon equilibrium factor was derived from measurements of indoor radon concentration and equilibrium equivalent radon concentration. Measurements were performed one day for each of 5 locations by using different active devices. Obtained radon equilibrium factors range from 0.36 to 0.7 which is in average larger than worldwide average of 0.4 Results are not surprising since measuring locations were kept closed during the measuring time, reducing therefore ventilation rate which as a consequence has an increase of equilibrium factor. Individual measuring results of indoor radon concentrations, equilibrium equivalent radon concentrations and radon equilibrium factors obtained with different detectors systems from 2 research teams was tested using Z – test. Obtained Z – score for each measurement vas below critical value, indication that there is no statistical difference between different measuring devices.XXXI Симпозијум Друштва за заштиту од зрачења Србије и Црне Горе, 06-08. октобар 2021.Proceedings: [https://vinar.vin.bg.ac.rs/handle/123456789/9668