Artificial Radionuclides Research Articles

Soil Radioactive Maps for Natural and Artificial Radionuclides and Estimation of Public Dose at East and North Bekaa – Lebanon

Soil Radioactive Maps for Natural and Artificial Radionuclides and Estimation of Public Dose at East and North Bekaa – Lebanon

Геоинформационная система для проектирования адаптивно-ландшафтных систем земледелия на радиоактивно загрязненной территории Тульского НИИ сельского хозяйства

GIS project was developed for the radioactively contaminated territory of the Tulskii NII. It was created in order to project the adaptive landscape agricultures. It was based on the information on the concentrations of 137Cs radionuclide in soil, compiled over 16 years. Electronic maps have been developed to create a GIS project and included the location of agricultural lands; crop rotation systems; distribution of specific activity values for artificial 137Cs radionuclide in agricultural lands; agrochemical indexes (the humus content, potassium content, contribution of phosphorus, the acidity), soil types, relief. The created GIS project and the corresponding data bases will be used to collect, store and analyse the results of the survey in order to project the adaptive landscape agricultures. Key words: GIS project, adaptive landscape agriculture, agricultural lands, radiation safety.

Separation method for Pu, Am and Sr in large air filter sample sets

A sequential separation method for Pu, Am, and Sr was applied for unusually large sample sets of air filters. The sample sets were combined weekly air filters covering sampling time from three months to five years, while in original method, the analyzed air filters had sampling time of only 1-3 days, containing significantly less organic and inorganic matrix and natural radionuclides. The separation method is based on ashing and wet-ashing, followed by column separations with extraction chromatography and anion exchange. Reference materials IAEA-447, IAEA-384, and NIST-SRM-4353A were analyzed with the modified separation method. IAEA-384 was representing best the composition and radionuclide level in the air filter samples.•Compared to the original method, sample ashing took considerably longer time (one day vs. several days).•High concentration of natural radionuclides in the large air filter sample sets interfered first the determination of 241Am and 90Sr, until an anion exchange step was adopted for removal of 210Bi and 210Po from Am and Sr fractions.•After modification, the method is suitable for separating artificial radionuclides 238,239,240Pu, 241Am, and 90Sr from large sample sets of air filters.

Plutonium Isotopes Research in the Marine Environment: A synthesis

Plutonium (Pu) isotopes are one of most important artificial radionuclides. Recent advances in analytical methodology of Pu have enabled Pu to play a vital role in tracing biogenic elements and pollutants transport, sediment deposition/resuspension and other marine process. The various ratios of Pu isotopes (238Pu, 239Pu, 240Pu and 241Pu), which are depende nt on the Pu sources, are useful for identifying the contributions from different sources, and these ratios can be utilized to indicate the marine processes. The aim of this manuscript is to provide an overview of the applications of Pu for studying various processes in the marine environment, such as the determination of recent sedimentation rate, to assess sediment transport and deposition/resuspension, water mass transport, etc, based on the knowledge and advances in the analytical methodology and the geochemical behavior of Pu. Furthermore, this work is expected to provide new insights for broadening the application of Pu in the marine environment and to help better understand land-sea interactions and global climate change.

DISTRIBUTION OF ARTIFICIAL RADIONUCLIDES IN AGGREGATE FRACTIONS OF SOILS IN THE VICINITY OF UNDERGROUND NUCLEAR TESTS CONDCUTED IN BOREHOLES AT “BALAPAN” SITE

The paper provides findings on distribution of artificial radionuclides in aggregate fractions of soils in radioactive fallout plumes near two Boreholes – 1301 and 1077 (the former ‘Balapan’ testing area), in which underground nuclear tests were conducted that differed in the nature of the real radiological situation. In the vicinity of Borehole 1301 in which an underground nuclear explosion was accompanied by the unforeseen release of debris into the atmosphere, the highest accumulation of 137Cs and 90Sr occurs in 250 to 1,000 µm fractions. Distribution of 241Am and 239+240Pu is characterized by two different tendencies – the predominant enrichment of 250 to 1,000 µm fractions in the near zone of the plume (up to 250 m) and predominantly enriched fractions of 5–8 µm and <1 µm in the distant plume area (700 to 2,500 m). Near Borehole 1077, near which the underground explosion is assumed to have been accompanied by escaping radioactive inert gases, 137Cs and 90Sr are mainly concentrated in less than 5 µm fractions, 241Am and 239+240Pu – in fractions of 8–40 µm and <1 µm.

Anthropogenic radionuclides in Antarctic biota – dosimetrical considerations

The article presents results of the research on artificial radionuclides (137Cs, 90Sr, 241Am) in the Antarctic environment. Samples of 12 species from the marine environment: Pygoscelis adeliae, Pygoscelis papua, Macronectes giganteus, Pagodroma nivea, Catharacta antarctica, Leptonychotes weddellii, Mirounga leonina, Harpagifer antarcticus, Chaenocephalus aceratus, Nacella concinna, Himantothallus grandifolius, Iridaea cordata (bones, feathers, soft tissues, eggs' shells of birds, bones, skin, fur of mammals, fish, mollusks’ soft tissues and shells, algae) and samples of 4 species from the terrestrial environment: Sanionia uncinata, Usnea antarctica, Usnea aurantiaco-atra, Deschampsia antarctica (mosses, lichens, grass) were investigated. Differences in the accumulation of 137Cs between marine and terrestrial ecosystem were shown, which are mostly due to conservatism of mosses and lichens and active removal of cesium by animal body. Furthermore discrepancy between mosses and lichens in the radioceasium accumulation was statistically proven with the additional use of Neutron Activation Analysis. Moreover, the internal weighted dose rates assessment was prepared using the ERICA Tool. The dose rates were relatively low, not exceeding several dozen nGy/h. Nonetheless, one species – Pagodroma nivea, was significantly outstanding due to the highest weighted dose rate it is burdened with.

OPTIMIZATION OF THE RADIOACTIVE AEROSOL SAMPLING AND MEASURING PROCEDURE WITH RESPECT TO RADON CONCENTRATION IN THE AIR.

High-volume aerosol samplers combined with laboratory analysis using high-resolution gamma ray spectrometry allow determining artificial radionuclides in the atmosphere at sub μBq/m3 levels. A major drawback of this procedure is a significant delay of the analysis result after any potential radioactive contamination deposition on the aerosol filter. Within the scope of the HAMRAD project, an autonomous device was developed in order to increase the sampling and measuring frequency. This approach yields higher detection limits (minimum detectable activity concentration [MDAC]) due to the deposited activity of radon decay products on the filter. In order to quantify the radon effect, a simple mathematical model was developed to predict MDAC for the particular radionuclide of interest for the given background conditions. It was found that MDAC can vary by a factor of ~2 for typical 'radon' conditions (~10Bq/m3) at SÚRO Prague and by a factor up to 5 for high radon concentration (100Bq/m3).

Environmental Radioactivity Monitoring and Assessment of Excess Lifetime Cancer Risk to People in Demra Thana, Dhaka, Bangladesh

Objective: The quality of life is influenced by the environment quality and one of the major factors that require a continuous monitoring is the level of radiation. Radiation protection is required to minimize the health effects due to radiation. It is essential to know real-time gamma radiation dose rates and calculation of annual effective dose of a country in order to generate the baseline database.
 Methods: The radiation monitoring was performed using real-time portable digital radiation monitoring device. This real-time digital portable radiation monitoring device meets all European CE standards as well as the American “FCC 15 standard”. The portable radiation monitoring device was placed at 1 meter above the ground on tripod and data acquisition time for each monitoring point (MP) was 1 hour. 35 MPs were selected for collection of radiation dose rates at different outdoor locations in Demra Thana, Dhaka from October-November 2019.
 Results: The measured dose rates due to natural radionuclides were ranged from 0.133 ± 0.022 µSv.h-1 to 0.251 ± 0.016 µSv.h-1 with an average of 0.187 ± 0.032 µSv.h-1. The annual effective dose to the population from outdoor environmental gamma radiation was varied from 0.232 ± 0.038 mSv to 0.440 ± 0.029 mSv with an average of 0.328 ± 0.057 mSv. Excess Lifetime Cancer Risk (ELCR) are also calculated which is ranged from 0.9×10-3 to 1.7×10-3 with an average value of 1.3×10-3, which is 4.5 times greater than world average of 0.29×10-3.
 Conclusion: This kind of study is required to detect the presence of natural radionuclides and artificial radionuclides (if any) releasing from nuclear and radiological facilities in the country or from neighboring countries for normal operations or in case of accident/incident. From this study, it can be concluded that there is no radiation burden to the environment due to man-made sources.

Comparing grain size composition of inter-rill and rill-eroded sediment from cultivated hillslope soils using caesium-134 and cobalt-60 as tracers

Understanding the extent to which textural characteristics of inter-rill and rill-eroded sediment differ across a range of agricultural soils is important in order to more accurately predict sediment transport capacities and thus increase the reliability of erosion models. However, a lack of consensus still exists over how much influence these two mechanisms exert on the physical characteristics of sediment during an erosion event. This communication reports results from a prototype tracing technique using two different artificial radionuclides to compare the grain size composition of inter-rill and rill-eroded sediment from eight different cultivated hillslope soils from southern England. A 1.0 m * 0.2 m * 0.11 m soil box was filled with soil labelled with caesium-134 (134Cs) to a depth of 0.1 m. A second layer of soil labelled with cobalt-60 (60Co) was distributed across the first soil layer, to a depth of 0.01 m, and lightly textured to replicate a fine tilth. The soil box was pitched at a ca. 17% slope (9.5°) and each soil was subjected to ca. 35 mm hr−1 of simulated rainfall until surface runoff was initiated and a rill developed. All runoff-eroded sediment was collected over 90 s intervals, dried and radiometrically assayed. Changes in radiometric signals were used to identify the transition from inter-rill to rill erosion, demarking a shift in sediment-source. Samples recording highest activity of either radionuclide were deemed to contain largest contributions of sediment mobilised by each respective erosion process and were selected for grain size analysis. Grain sizes, measured at 10 percentile intervals, were subjected to a paired-sample statistical analysis to determine whether size-difference was significant. Rill-eroded sediment was significantly coarser than inter-rill eroded sediment for four soils, whereas inter-rill eroded sediment was significantly coarser than rill-eroded sediment for one soil. There was no significant size-difference for two soils, and one soil was omitted from statistical analysis due to excessive contamination by the sub-dominant erosion process.

The radioactive contamination study in south-western Greenland tundra in 2012–2013

The paper presents results of the radioecological investigation carried out in south-western Greenland shoreline. There were examined over 50 samples of lichens and mosses collected from 7 locations during two scientific expeditions conducted in the summer of 2012–2013. The levels, trends and the most likely origin were determined for following natural and artificial radionuclides: 90Sr, 137Cs, 230, 232Th, 234, 238U, 238, 239+240Pu and 241Am. The radioactive pollution was found as relatively low, reaching the maximum values at: 25.3 ± 2.04 Bq/kg for 90Sr, 293 ± 27 Bq/kg for 137Cs, 4.01 ± 0.13 Bq/kg for 239+240Pu, 0.1381 ± 0.0070 Bq/kg for 238Pu and 1.90 ± 0.21 Bq/kg of 241Am, 9.15 ± 0.48 Bq/kg for 230Th, 25.1 ± 1.2 Bq/kg for 232Th, 7.5 ± 1.5 Bq/kg for 234U and 7.26 ± 0.80 Bq/kg for 238U. Both activity and mass isotopic ratio assays revealed dominant contribution of the global fallout + SNAP 9A on the presence of plutonium isotopes and 241Am in Greenland tundra. However, noticeable deviations of 241Am/239+240Pu and to a lesser extend of 240Pu/239Pu ratios from the GF level have been observed. The origin of 137Cs was evidently connected with the coexistence of global and Chernobyl fallout, while the presence of 90Sr was caused by nuclear weapon tests and affected by leaching process. The seaborne signature of uranium isotopes was manifested in research material as well.

Sedimentation rates (data on 210pb and 137cs radionuclides) in different facial-genetic types of the Kara sea bottom sediments

In the article original data on isotope composition of natural excess Pb-210 and artificial Cs-137 radionuclides in upper 2550-cm layer of sea-bottom sediments at the Kara Sea (from Ob and Yenisei estuaries, Eastern-Novaya-Zemlya trough, Voronin trough, as well as Sedov bay (Novaya Zemlya)) are presented. The research results showed close tie between sedimentation rates and facial-genetic types of the sea-bottom sediments. Highest sedimentation rates are typical for the terrigenic-estuarine type. The type is divided on tractional load with sedimentation rate 0.40.7 cm per year and mud bank sediments with sedimentation rate 0.71.0 cm per year. The terrigenic-shallow-marine type is characterized by lowest sedimentation rate 0.10.3 cm per year. The background terrigenic-marine type has a broadest spectrum of the sedimentation rates: on trough slope the rates are minimal (likely to terrigenic-shallow-marine type), within central parts of the trough (as a result of gravity creep) the rates may increase up to 0.9 cm per year. Single facial-genetic type is glacial sediments of Navaya Zemlya bays. Measured recent sedimentation rate within inner depression of the Sedov bay is 0.10.2 cm per year.

Dampak Radiasi Radioaktif Terhadap Kesehatan

Radioactive elements or radionuclides in the environment can be grouped into two big categories, namely natural radionuclides and artificial radionuclides that both can serve as a source of radiation nature or environment. Source radiation source nice neighborhood the physical and fabrications can serve as a source of radiation on the human body. Radiation received the human body can come from sunber and external internal. An external source is the source of radiation lying outside the human body, while internal resources are a source of radiation inside the human body.

Comparative analysis of water contamination of the Shagan river at the Semipalatinsk test site with heavy metals and artificial radionuclides

The purpose of this paper is to determine the degree of contamination of the largest waterway of the Semipalatinsk Nuclear Test Site (STS), the Shagan River, with heavy metals and artificial radionuclides. With the data obtained by the long term monitoring results, we identified the most significant contaminants and determined the most contaminated reaches of the Shagan River. The contamination indices for heavy metals were calculated and applied to evaluate possible usage of the Shagan River water for domestic purposes.

Biomonitoring of radioactive contamination of the Yenisei River using aquatic plants

The Yenisei River is contaminated by artificial radionuclides released by one of the Russian facilities producing weapons-grade plutonium (the Mining-and-Chemical Combine, MCC), which has been in operation for 60 years. The paper presents results of long-term monitoring of radionuclide concentrations in six aquatic plant species collected from the 1400 km Yenisei River stretch downstream of the city of Krasnoyarsk. Before the last MCC reactor was shut down (in 2010), up to 30 artificial radionuclides were detected in the plant biomass, and 2 and 5 years after the reactor shutdown, 11 and 3–5 radionuclides, respectively, were detected. The highest concentrations of radionuclides were recorded in Fontinalis antipyretica. The aquatic plant Elodea canadensis, which commonly occurs in the Yenisei River, was used in the cytogenetic study. High frequencies of chromosomal aberrations (up to 33%) were revealed in cells of Elodea canadensis roots from the Yenisei region affected by the MCC radioactive discharge, at dose rates of 45–72 μGy/d, while in the cells of the plant roots from the reference areas, the frequency of chromosomal aberrations was 5–7%, at dose rates below 2 μGy/d. The higher frequencies of chromosomal aberrations in Elodea canadensis collected from the parts of the River with increased concentrations of artificial radionuclides are associated with the radiation factor. The aquatic plant Elodea canadensis can be recommended as a bio-indicator for radioactively contaminated aquatic ecosystems.

Characterisation of the natural gamma-ray background in the underground Callio Lab facility

Herein, we measured the natural gamma-ray background in a new underground laboratory facility within Pyhäsalmi Mine in Finland at a depth of 1430 m (~4100 m.w.e). The radionuclide compositions of the rocks in the walls along with the shotcrete on the walls were investigated. The specific activities of the natural radionuclides in these materials were calculated. The measured spectra of the natural gamma-ray background and calculated minimal detected activities of several natural and artificial radionuclides are presented.

The contents of artificial and natural radionuclides in tissues of the Percidae fish from the Dnipro Reservoir

The contents of artificial and natural radionuclides of 137Cs, 90Sr, 226Ra, 232Th, and 40K had been investigated in muscle and bone tissues, gill petals, and scales of common perch Perca fluviatilis and pikeperch Sander lucioperca from two fishing areas of the Dnipro (Zaporizhzhia) Reservoir. The specific radionuclide activities were measured with the SEG-001 “AKP-C” and SEB-01-150 scintillation spectrometers of gamma- and beta-radiation energy in Bq/kg of wet weight. The radioactive elements of both natural and artificial origins were concentrated greatly in common perch tissues compared to pikeperch. The bone and muscle tissues contained the maximal levels of radionuclides, while respectively smaller amounts of radionuclides were found in gills and scales. The radionuclide levels in the tissues of investigated fish species were significantly higher in the Dnipro Reservoir area with weak flowage and slow water exchange.

Sedimentation Rates in Different Facies–Genetic Types of Bottom Sediments in the Kara Sea: Evidence from the 210Pb and 137Cs Radionuclides

The paper presents authors' original data on the isotope composition of the natural “excess” Pb‑210 and artificial Cs-137 radionuclides in the upper 25- to 50-cm layer of sea-bottom sediments in the Kara Sea (from the Ob and Yenisei estuaries, Eastern Novaya Zemlya trough, Voronin trough, and Sedov bay at the Novaya Zemlya). Sediment cores were collected during Cruises AMK-63 and AMK-66 of the R/V Akademik Mstislav Keldysh in 2015 and 2016. Results of this research show strong correlations between the sedimentation rates and facies-genetic types of the sea-bottom sediments. The highest sedimentation rates are typical of the terrigenous–estuarine sediments, which are subdivided into tractional load, whose sedimentation rate is 0.4–0.7 cm per year, and “mud bank” sediments, whose sedimentation rate is 0.7–1.0 cm per year. The terrigenous shallow marine sediments are characterized by the lowest sedimentation rate of 0.1–0.3 cm per year. The background terrigenous marine sediments show broad variations in the sedimentation rates: these rates are at a minimum (and comparable to the sedimentation rates of the terrigenous shallow marine sediments) on trough slopes and can increase to 0.9 cm per year in the central parts of the trough (as a result of gravity creep). The glacial sediments of Novaya Zemlya bays belong to a separate individual type. The measured “current” sedimentation rate within the inner depression of the Sedov bay is 0.1–0.2 cm per year.

A study of the radiological baseline conditions around the planned Sinop (Turkey) nuclear power plant using the mapping method.

This study makes a first attempt at a detailed estimation of the background radioactivity level and its distribution at the Sinop nuclear power plant site. The activity concentration levels of 226Ra, 232Th, 40K and 137Cs radionuclides in soil samples collected from 88 locations around Sinop Province, Turkey, in November 2016, were measured using gamma spectrometry. The distributions of radionuclide levels obtained from the results were evaluated using a geostatistical method, and the estimated radiation levels were determined using the ordinary kriging (OK) method, which is the best linear unbiased estimator (BLUE) for unmeasured points. Estimates of distribution results were evaluated using cross-validation diagrams, and it was shown that the OK method could predict radiological distributions for appropriate criteria. Finally, using the kriging parameters, distributions of radiation levels for the entire work area were mapped at a spatial resolution of 100 × 100m2. These maps show that the natural radionuclides (226Ra, 232Th and 40K) are distributed at higher levels to the southeast of Sinop than in the other regions, and the activity of an artificial radionuclide (137Cs) is high in the interior and northern sections.

К разработке новых редакций норм радиационной безопасности и основных санитарных правил обеспечения радиационной безопасности

The objective of this work is to enhance national Radiation safety standards (NRB) and Basic Health Rules for Radiation Safety (OSPORB). 
 This article discusses proposals how to amend new versions of the fundamental regulatory documents – national NRB and OSPORB as regards the interpretation of the term “limit of the annual effective dose of manmade individual exposure” and the health physics limiting the content of artificial radionuclides in solid materials for their unrestricted use. 
 In current Radiation Safety Standards, NRB-99/2009 (paragraph 3.1.5.), in contrast to the Federal Law of 09.01.1996 No 3-FZ “On the Public Radiation Protection” and provisions of draft International Basic Safety Standards, annual effective dose means gross effective dose of external and internal exposure, received for the calendar year. The article describes the situation where the doses of a conditional worker do not exceed the dose limits in a single calendar year, i.e. < 50 mSv, however, for any arbitrarily taken time interval equal to one year, the annual dose limit of 50 mSv is repeatedly exceeded. Therefore, the following amendment is proposed to be made in new version of the NRB: “Annual effective dose means the sum of the effective external dose received for any arbitrarily taken time interval equal to one year and the ambient effective internal dose due to the intake of radionuclides in the body over the same period”.
 In current Basic Health Rules for Radiation Safety, OSPORB 99/2010, Annex 3 “The Specific Activities of Artificial Radionuclides, at which Unrestricted Use of Materials is Permitted” does not include the uranium isotopes 234U, 235U and 238U; this contradicts paragraph 5.2.10 of OSPORB-99/2010, according to which these isotopes should be attributed to manmade radiation sources. 
 The article justifies the expediency of establishing the upper value of the specific activity of 1 Bq/g for the main uranium radionuclides in solid materials in case of their unlimited use. 
 The supplement of Appendix 3 is proposed to the new version of the OSPORB with uranium isotopes 234U, 235U, 238U, setting the standard for their specific activity of 1 Bq/g in solid materials for unlimited use.

CONCENTRATION OF ARTIFICIAL RADIONUCLIDES IN PINUS SILVESTRIS AT THE PLUMES OF RADIOACTIVE FALLOUTS RESULTED FROM THE FIRST SURFCAE NUCLEAR TEST AT SEMIPALATINSK TEST SITE

The work provides results of research of concentrations of 137Cs, 90Sr, 241Am, 239-240Pu artificial radionuclides in pine forest at the part of the radioactive fallouts plume of the first nuclear test (29.08.49), conducted at Semipalatinsk Test Site. The maximum specific activity values in soil were found to be typical for 239+240Pu and 137Cs, lower values were found for 90Sr and in single case it was registered for 241Am. In the phytogenous objects, represented by structural elements of pine (Pinus silvestris) trunk, mainly 239+240Pu and 90Sr was accumulated, at that the maximum values were registered in the cortex.