scholarly journals Tritium contaminated soil in sites for Semipalatinsk above-ground nuclear tests

2020 ◽  
Vol 29 (4) ◽  
pp. 106-117
Author(s):  
L.V. Timonova ◽  
◽  
О.N. Lyakhova ◽  
А.О. Aidarkhanov ◽  
Z.B. Serzhanova ◽  
...  
Keyword(s):  
Specific Activity ◽  
Basic Mechanism ◽  
Soil Samples ◽  
Atmospheric Fallout ◽  
Field Site ◽  
Tritium Content ◽  
Tritium Production ◽  
Nuclear Explosions ◽  
Experimental Field ◽  
Nuclear Tests

Semipalatinsk above-ground nuclear tests caused atmospheric fallout and radioactive contam-ination of the environment that resulted in the synthesis of great amount of radioisotopes. Triti-um was the basic isotope generated in the soil as a result of above-ground nuclear tests. Previ-ously many researchers believed that tritium contamination of the soil occurred in sites for un-derground nuclear tests only. The research of tritium content in areas for above-ground nuclear tests was not taken into consideration. However, during the work in the site for above-ground tests “Experimental Field”, we examined the tritium content in soil and numerically estimated the specific activity of 3H. Because the radioisotope may be produced from the following activa-tion reactions while nuclear explosions: 6Li3 + n → 4He2 + 3Н; 10B5 + n → 24He2 + 3Н; 14N + n → 12C + 3Н, as well as 151Eu63 + n → 152Eu63 , we selected soil samples to test for 3H, as well as for 152Eu. Then analysis results were compared for establishing relationship between the isotopes and investigating the mechanism of 3H production. The article presents results of detailed study of soil contaminated with tritium in the “Experimental Field” site. 3H content in soil and the iso-tope distribution in epicenter zones of technical sites and in sites located in different distance from the epicenter are presented. Correlated dependence of the 3Н content on the 152Eu content that allowed us to discover the basic mechanism of the tritium production, that was a neutron-activation reaction occurred at the time of above-ground nuclear tests.

scholarly journals INVESTIGATION OF RELATIONSHIP BETWEEN PINE (PINUS SYLVESTRIS L.) BIOMASS AND 137CS SPECIFIC ACTIVITY IN WOOD

2006 ◽  
Vol 14 (3) ◽  
pp. 135-140 ◽  
Author(s):  
Donatas Butkus ◽  
Ingrida Pliopaitė Bataitienė
Keyword(s):  
Power Plant ◽  
Pinus Sylvestris ◽  
Nuclear Power ◽  
Specific Activity ◽  
Chernobyl Nuclear Power Plant ◽  
Biomass Growth ◽  
Annual Rings ◽  
Global Pollution ◽  
Nuclear Explosions ◽  
Average Value

The paper analyses relationship between pine (Pinus sylvestris L.) biomass and the specific activity of an artificial radio‐isotope 137Cs in wood. The specific activity of 137Cs was measured in the segments of pine (Pinus sylvestris L.) annual rings. The biomass of segments and the density of wood were estimated experimentally. It is determined that relationship between pine (Pinus sylvestris L.) biomass and pine age is not linear. In the variation of biomass are time when biomass grows slowly (25–55 pine age or 1959–1990 m. period). The specific activity of 137Cs in pine annual rings depends on the rapidity of biomass growth. The specific activity of 137Cs varied from 0,3 ± 0,1 to 13,4 ± 2,7 Bq/kg when the biomass grew rapidly and its average value was 4,3±1,1 Bq/kg. When the biomass grew slowly, the specific activity of 137Cs varied from 1,8 ± 0,7 to 20,6 ± 5,3 Bq/kg, and its average value was 9,6 ± 2,6 Bq/kg. Global pollution after nuclear explosions, pollution after the Chernobyl Nuclear Power Plant accident and uptake of 137Cs from roots had an influence on the specific activity of 137Cs in pine annual rings.

Specific Activity and Radioactive Contour Maps of Natural (40K, 226Ra and 232Th) and Anthropogenic (137Cs) Radionuclides in Surface Soil Samples from Phang Nga Province, Thailand

2014 ◽  
Vol 979 ◽  
pp. 35-38
Author(s):  
Prasong Kessaratikoon ◽  
Ruthairat Boonkrongcheep ◽  
Supphawut Benjakul ◽  
Suchin Udomsomporn
Keyword(s):  
Dose Rate ◽  
Surface Soil ◽  
Specific Activity ◽  
Hazard Index ◽  
Research Data ◽  
Soil Samples ◽  
Gamma Ray Spectrometry ◽  
The South ◽  
Absorbed Dose Rate ◽  
Contour Maps

The specific activity of the natural (40K, 226Ra and 232Th) and anthropogenic (137Cs) radionuclides have been studied and evaluated for 97 surface soil samples collected from 7 districts of Phang Nga province in the south of Thailand. High-purity germanium (HPGe) detector and gamma ray spectrometry analysis system were employed to measure and analyze the experimental results. It was found that, the ranges of specific activities of 40K, 226Ra, 232Th and 137Cs in surface soil samples are 251.50 – 15740.34, 15.21 – 791.42, 18.14 – 854.34 and < 0.33 – 16.91 Bq/kg with average values are 2886.77 ± 225.93, 165.71 ± 8.45, 160.36 ± 7.93 and 5.76 ± 2.49 Bq/kg, respectively. The results were also compared with some research data in national and global radioactivity measurement and evaluations. Furthermore, the radiological hazards of Phang Nga province were calculated through the radium equivalent activity (Raeq), the external hazard index (Hex), the gamma absorbed dose rate (D) and the annual effective dose rate (AEDout) and also compared with research data in the south of Thailand and the safety limits recommended values by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Moreover, the radioactive contour maps of the natural (40K, 226Ra and 232Th) and anthropogenic (137Cs) radionuclides have been also created for the investigated area.

Effects of Secondary Sources of Underground Nuclear Explosions on the mb : Ms Criterion and Implications for Discrimination of the DPRK’s Nuclear Tests

2020 ◽  
Author(s):  
Henglei Xu ◽  
Sidao Ni ◽  
Ping Jin ◽  
Shiban Ding ◽  
Hongchun Wang
Keyword(s):  
Body Wave ◽  
Test Site ◽  
Nuclear Test ◽  
Source Spectrum ◽  
Secondary Source ◽  
Underground Nuclear Explosions ◽  
Nuclear Explosions ◽  
Secondary Sources ◽  
Nuclear Tests ◽  
Recognition Criterion

ABSTRACT The mb :  Ms (mb vs. Ms) relationship is an important criterion for screening explosions from earthquakes and has been widely adopted in seismological monitoring by the Comprehensive Nuclear-Test-Ban Treaty Organization. In general, the earthquakes have larger Ms than the underground explosions with equivalent mb. However, it has been reported that this recognition criterion failed to identify some explosions at the North Korea nuclear test site. In this study, we investigate the potential effects of secondary source components, including the compensated linear vector dipole (CLVD) and double-couple (DC) sources, on mb and Ms magnitude measurements and the physical mechanism of the mb :  Ms recognition criterion by calculating synthetic seismograms. The results show an apparent critical body-wave magnitude of 5 when using the mb :  Ms method to discriminate North Korean underground nuclear explosions. The Ms measurements decrease as the CLVD components increase, whereas the effects from the DC source can be neglected. Small events, such as the first five North Korean nuclear tests, generate weak CLVD components, leading to the failure of mb :  Ms-based discrimination, whereas the last event, with a larger magnitude, caused extensive damage and hence can be successfully discriminated. In addition, the large difference between the source spectrum of explosions and those of earthquakes might be another important factor in the successful mb :  Ms-based discrimination of the sixth North Korean nuclear test.

scholarly journals THE FACTOR OF IONIZING RADIATION AND THYROID CANCER IN WOMEN IN THE ALTAI KRAI

2017 ◽  
Vol 22 (4) ◽  
pp. 224-228
Author(s):  
A. F Lazarev ◽  
Ya. N Shoikhet ◽  
L. F Pisareva ◽  
Valentina D. Petrova ◽  
S. A Terekhova
Keyword(s):  
Thyroid Cancer ◽  
Ionizing Radiation ◽  
Comparison Group ◽  
Test Site ◽  
Incidence Rates ◽  
Main Group ◽  
Female Population ◽  
Nuclear Explosions ◽  
Semipalatinsk Test Site ◽  
Nuclear Tests

The purpose of the study was to study the dynamics of the incidence of thyroid cancer in the female population of the Altai Territory during the period of 1992-2016. Studies were performed with the use of data of the patient register of thyroid cancer, including information on 3026 women, with the use of methods of modern medical statistics. Intensive and standardized indices were calculated for the female population, resided near to traces of nuclear explosions executed at the Semipalatinsk test site, in the zone of the most significant radiation doses (the Main group). As a comparison, incidence rates of the remaining population of the Altai Territory (the Comparison group) and average values for the region were used. The article presents results of a descriptive epidemiological study of the incidence of thyroid cancer in the Altai Territory over 25 years (1992-2016). The results of the probabilistic association of the incidence of thyroid cancer with the ionizing radiation factor due to nuclear tests at the Semipalatinsk test site were obtained. The dynamics of the incidence of thyroid cancer by the data for five-years periods (averaged data): 1992-1996; 1997-2001; 2002-2006; 2007-2011 and 2012-2016 was studied in various territories of the Altai Territory: both on the traces of nuclear explosions - the main group, and in the rest territory (the comparison group), indices of average values for the regions. There were revealed the dynamics of the incidence of thyroid cancer in tens of years after nuclear tests in the population living in the zone with the most significant doses of radiation and its gradual decrease, due to rehabilitation measures. New approaches to the formation of high cancer risk groups for thyroid cancer in the Altai Territory are substantiated.

scholarly journals Lipolytic Activities of Bacteria and Fungi Isolated from Soil Samples

2021 ◽  
pp. 27-43
Author(s):  
Racheal Oluwayemisi Fashogbon ◽  
Bose Adebayo ◽  
Victoria Musa ◽  
Titilayo Femi-Ola
Keyword(s):  
Lipase Activity ◽  
Metal Ion ◽  
Specific Activity ◽  
Soil Samples ◽  
Bacillus Sp ◽  
State University ◽  
Sudan Black B ◽  
Fusarium Sp ◽  
Microbial Lipases ◽  
Bacteria And Fungi

This study was carried out at the Department of Microbiology, Microbiology Laboratory, Ado-Ekiti State University, Ekiti State, Nigeria between July, 2018 to March, 2019. Due to the diverse biotechnological importance of lipases as a biocatalytic enzyme, extracellular production of microbial lipases has to gain lots of interest. This study, therefore, focused on the physicochemical parameters of lipase producing microorganisms from different soil samples. Microorganisms were isolated from four different soil samples using Nutrient Agar (NA) and Potato Dextrose Agar (PDA). The isolates were identified and characterized. Production, an assay for Lipase enzymes, purification, the effect of pH, Temperature and metal ion was investigated. The isolates were culturally, morphologically and biochemically characterized. Two of the bacteria strains (Bacillus sp. and Staphylococcus sp.) and four fungi (Fusarium sp., Aspergillus fumigatus, Aspergillus niger, and Trichophyton sp.) isolates were able to produce lipid using Sudan Black B Fat staining techniques. Fusarium sp. isolated from dumpsite soil had the highest specific lipase activity (21.16 µmol/min/ml) while Bacillus sp. isolated from red oil spill soil had the highest lipase activity (0.59 µmol/min/mg). The specific activity of partially purified lipase for Fusarium sp. was 2.39 µmol/min/mg while Bacillus sp. had a specific activity of 2.46 µmol/min/mg. 30oC - 50oC, pH 7.0 to 9.0 and KCl2 (139.672%) supported the highest production of lipase by the Bacillus sp. and Fusarium sp. This study demonstrated that the Bacillus sp. produced a high amount of lipase activity followed by Fusarium sp. Extensive and persistent screening for new microorganisms and their lipolytic activities will help to provide faster ways to solve most environmental soil pollution.

scholarly journals Natural Radioactivity Levels in Soil Samples of AL- Sadr and AL-Forat AL-Aosat Hospitals in Najaf

2018 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Natural Radioactivity ◽  
Specific Activity ◽  
Hazard Index ◽  
Absorbed Dose ◽  
Soil Samples ◽  
Absorbed Dose Rate ◽  
Average Value ◽  
Radiation Risks ◽  
External Hazard Index ◽  
Radium Equivalent

This work was undertaken with the purpose of measuring natural radioactivity, due to 238U, 232Th and 40K in 30 soil samples collected from two hospitals in the governorate of (AL-Najaf), in Iraq. The samples were distributed (15) samples per hospital, and Radiation risks were also calculated for all soil samples. The natural radioactivity was measured using NaI (Tl) detector, the results of the specific activity at the Al Sadr Hospital were 238U ranged from (5.89±0.36 to 21.38±0.69) (Bq/kg) with average value 12.60±0.51 (Bq/kg). 232Th from (0.44±0.06 to 14.67±0.37) (Bq/kg) with average value (4.46±0.19) (Bq/kg), and 40K from (252.14±2.54 to 478.24±3.50) (Bq/kg) with average value (346.95±289) (Bq/kg). AL-Forat AL-Aosat hospital results were 238U ranged from (0.69±0.12 to 27.63±0.74) (Bq/kg) with average value (12.84±0.51) (Bq/kg), 232Th from (1.47±0.11 to 9.3±0.31 (Bq/kg) with average value 6.19±0.24 (Bq/kg), and 40K from (192.88±2.27 to 338.52±3.08) (Bq/kg) with average value (254.29±2.54) (Bq/kg). The radiation risks calculated, Radium Equivalent (Raeq), external Hazard index (Hex), absorbed dose rate (ADr), total Annual Effective Dose Equivalent (AEDE), and the Excess Life Cancer Risk (ELCR). The results were for Al Sadr Hospital (45.7063(Bq/kg), 0.1234, 23.0648(nGy/h), 0.0283(mSV/y), 1.247439702×10-3) respectively. For AL-Forat AL-Aosat hospital were (41.2655 (Bq/kg), 0.111, 20.3772 (nGy/h), 0.0250(mSV/y)`, 1.102083688×10-3) respectively. The results in the two hospitals were compared with the global allowable values ratio within the permissible ranges specified by UNSCER, OCDE, and ICRP; we concluded that all the sites in this study are safe.

scholarly journals Radiation-hygienic characteristic of the protected zones of peaceful nuclear explosions in the Arkhangelsk region

2021 ◽  
Vol 14 (1) ◽  
pp. 111-123
Author(s):  
E. V. Khramtsov ◽  
V. S. Repin ◽  
A. M. Biblin ◽  
K. V. Varfolomeeva ◽  
S. A. Ivanov
Keyword(s):  
Gamma Radiation ◽  
Specific Activity ◽  
Seismic Exploration ◽  
Dose Equivalent ◽  
Nuclear Explosions ◽  
Arkhangelsk Region ◽  
Local Soil ◽  
Ambient Dose Equivalent ◽  
Ambient Dose ◽  
Protected Zone

The article presents data on the radiation situation on the territories of the protected zones of peaceful nuclear explosions «Globus-2», «Agat» and «Rubin-1» based on the results of field studies in 2020. Peaceful nuclear explosions were conducted in the Arkhangelsk region for seismic exploration. The results of the radiation-hygienic state of protected zones and radiation safety in the territories adjacent to peaceful nuclear explosions are analyzed by the main indicators: the values of the ambient dose equivalent of gamma radiation, the identification of gamma-emitting radionuclides in situ by field gamma spectrometry, the specific activity of technogenic radionuclides in the soil and tritium in the water of reservoirs and drinking water sources. An assessment of the sanitary condition of the studied territories of protected zones of peaceful nuclear explosions is given. It was found that the levels of the ambient dose equivalent rate of the gamma radiation at all sites are at the level of fluctuations in the natural regional radiation background in the range of 0.08-0.20 microSv/h. On the territory of the protected zone of the peaceful nuclear explosion «Globus-2» were repeatedly identified areas of minor local soil contamination with 137Cs (the previous study was performed in 2011). Increased values of the ambient equivalent dose rate of gamma radiation (0.20 -0.22 μSv/h) and specific activity of 137Cs in two soil samples (154 and 160 Bq/kg, respectively) were found in these areas. The tritium content in the water of water supply sources does not exceed 5 Bq/kg. These values are typical for global levels of this radionuclide in water bodies. Remains of technological equipment were found on the territories of the protected zones of the peaceful nuclear explosions (especially in the protected zone of the explosion «Agat»), as well as rusty metal pipes and barrels, the remains of wooden structures, etc. Information signs installed on dilapidated concrete foundations at the mouths of combat wells of all surveyed peaceful nuclear explosions have subtle inscriptions. The presence of forest thickets in the places where the investigated peaceful nuclear explosions are conducted and their ignition during forest fires is a potential threat to the release of technogenic radionuclides during depressurization of the mouths of combat wells.

scholarly journals Mapping of Natural Radioactivity in Soil Samples of Kufa Districts, Iraq Using GIS Technique

2021 ◽  
Author(s):  
Lubna A. Alasadi ◽  
Ali Abid Abojassim
Keyword(s):  
Natural Radioactivity ◽  
Specific Activity ◽  
Detection System ◽  
Soil Samples ◽  
Average Value ◽  
Radiological Parameters ◽  
Three Samples ◽  
Safety Limit ◽  
Potassium 40 ◽  
Thorium 232

Abstract The aim from this work is to detect and draw the natural radioactivity of (uranium-238, thorium-232 and potassium-40) levels in soil samples that taken from Kufa districts, Najaf governorate, Iraq. The detection system used in study is NaI (Tl) with "3x3" dimension, while maps were drawn by geographic information system (GIS). Some radiological parameters were calculated depending on measuring of specific activity for 238U, 232Th, and 40K. The results of the average value with standard error in all samples of the present study for 238U, 232Th, 40K, and 235U were 6.2±0.74, 6.41±0.82, 278.10±19.43, and 0.28±0.03 Bq/kg, respectively. The specific activity of Uranium-238, Thourium-232, poasium-40 and Uranium-235 found in all soil samples were within the safety limit reported by UNSCEAR, except three samples have poasium-40 higher than safety limit. Also, the results of radiological parameters were all found to be below OECD, UNSCEAR safety limit. Generally, the average of specific activity in soil collected arranged of potassium-40 > thorium-232 > uranium-238. Mapping GIS for natural radioactivity and some radiological parameters were successfully draw for the study area. Finally, natural radioactivity and radiological parameters for soil samples at Kufa districts were safety.

Full Moment Tensor Solutions of U.S. Underground Nuclear Tests for Event Screening and Yield Estimation

2021 ◽  
Author(s):  
Michael E. Pasyanos ◽  
Andrea Chiang
Keyword(s):  
Moment Tensor ◽  
Test Site ◽  
Event Identification ◽  
Nuclear Explosions ◽  
Explosion Monitoring ◽  
Yield Determination ◽  
Nuclear Tests ◽  
Chemical Explosions ◽  
Material Conditions ◽  
Full Moment Tensor

ABSTRACT Moment tensor (MT) solutions are proving increasingly valuable in explosion monitoring, especially now that they are more routinely calculated for the unconstrained, full (six component) MT. In this study, we have calculated MTs for U.S. underground nuclear tests conducted at the Nevada National Security Site using seismic recordings primarily from the Livermore Nevada Network. We are able to determine them for 130 nuclear explosions from 1970 to 1996 for a range of yields and under a variety of material conditions, which we have supplemented with 10 additional chemical explosions at the test site. The result is an extensive database of MTs that can be used to assess the performance of important monitoring tasks such as event identification and yield determination. We test the explosion event screening on the fundamental lune of the MT eigensphere and find MT screening to be a robust discriminant between earthquakes and explosions. We then explore the estimation of moment-derived yield, in which we find that material properties are the largest contributor to differences in the estimated moment-to-yield ratio. Further research conducted on this dataset can be used to develop, test, and improve various explosion monitoring methodologies.

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