Study Of Natural Radioactivity Research Articles

High count rate alpha particle spectroscopy by a digital optical camera: A comparison study on edge detection algorithms

Alpha particle spectroscopy is highly significant in technologies related to radioactivity, particularly in radiation safety and the study of natural radioactivity. On the other hand, tools capable of identifying and determining the energies of alpha particles are of great interest. Among these tools, Commercial Off-The-Shelf (COTS) instruments, which can be used for alpha particle detection, have gained significant importance due to their ease of use and low cost. In this study, alpha particle spectroscopy of a Ra-226 source has been performed using a commercial digital camera based-on a CMOS sensor. In order to determine energy spectrum of alpha particles emitted from the source, the performance of various edge detection algorithms was examined. An algorithm based-on local pixel changes was introduced and implemented. By comparing the run times of the algorithms, it was shown that the algorithm proposed in this article exhibited the shortest run-time. Additionally, a method for rejecting pile-up events to correct their destructive effects on the alpha particle energy spectrum was introduced and implemented.

Study of natural radioactivity and trace-element content capable of generating long-lived γ-ray activity in cements

Cement is an important component of concrete used as a shielding material in nuclear accelerators and reactors. Hence cement samples should be analysed for the presence of certain trace elements that may get activated by neutrons emitted during the production of radioisotopes in an accelerator, so as to minimize the low level radioactive waste to be handled during decommissioning. With this motivation the present work was undertaken and 44 samples of five broad classes of cements were analysed for natural radioactivity (226Ra, 232Th & 40K) and trace elements capable of generating long lived gamma radioactivity due to neutron activation.

Studies on natural radioactivity in rocks of Coorg district, Karnataka state, India

The paper deals with the study of natural radioactivity in the rocks of Coorg district, Karnataka state. The samples were analyzed by NaI(Tl) based gamma ray spectrometer. The activity of 232Th varies from 16.46 Bq kg−1 to 160.84 Bq kg−1 with mean value of 79.05 Bq kg−1. The activity of 40K varies from 96.72 Bq kg−1 to 933.68 Bq kg−1 and that of 226Ra was found to vary from BDL to 34.36 Bq kg−1. A correlation coefficient of R = 0.81 was found between 232Th activity and 40K activity. The correlation between 226Ra activity and 232Th activity is R = 0.59. The correlation between 40K and 226Ra is R = 0.51. The Radium Equivalent Activity (Raeq) ranges from 46.78Bq kg−1 to 315.55Bq kg−1. The absorbed gamma dose rate (D) ranges from 21.28 nGy h−1 to 141.45 nGy h−1, with an average of 73.37 nGy h−1. The radionuclides activity was compared with world average values. The external Hazard index (Hex) varies from 0.12 to 0.84. The internal hazard index (Hin) is in the range 0.15–0.89. The hazard indices were found to be within safety limits.

Assessment of Natural Radioactivity and radiation hazards in beach sand samples from Kanyakumari District, TamilNadu

<div><p><em>Natural radionuclides of terrestrial origin have very long half – lives or driven from very long – lived parent radionuclides, which have been created in stellar processes before the earth formation. The study of natural radioactivity in marine and coastal environments is of significant importance for better understanding of oceanographic and sedimentological processes. The sampling sites are selected to cover randomly to cover the southern part. The soil samples have been collected in beach sides. In situ gamma measurements were conducted using a high-purity germanium (HPGe) detector (coaxial cylinder of 50.1 mm in diameter and 44 mm in length) with a relative efficiency of 50% and an energy resolution (FWHM) of 1.8 keV at the 1.33 MeV reference transition of <sup>60</sup>Co. The measurements shows that the values of the absorbed dose rates in air in the investigated area are lower than the recommended limit by the United Nations Scientific Committee on the Effect of Atomic Radiation.</em></p></div>

Study of natural radioactivity in Lake Miri in South West of Sudan

The focus of this study is to investigate the suitability of Lake Miri, a lake with high natural radioactivity in the southwest of Sudan, as a water source for nearby villages. Soil, water, foodstuffs and vegetable samples were collected and analyzed. The results indicate that the mean natural radioactivity level in the study area is 450nGy/h, which is ten times greater than other places in Sudan with normal background (40nGy/h) natural radioactivity, and these findings demonstrate that the average annual exposure of the population is 38.4mSv.

Evaluation of naturally occurring radioactivity across the State of Kuwait using high-resolution gamma-ray spectrometry

A study of natural radioactivity from 90 different soil samples from the state of Kuwait has been carried out to ascertain the NORM concentration values across the country. The calculated activity concentrations were determined from: (i) the decays of the 226Ra, 214Pb and 214Bi members of the 4n+2 decay chain headed by 238U and; (ii) the 228Ac, 212Pb and 208Tl members of the 4n chain headed by 232Th. The study also included evaluations for the 235U decay chain with the 186keV doublet transition used together with the measured 4n+2 activity concentration values to determine the 235U/238U isotopic ratios for each sample. The values for the arithmetic mean activity concentrations for 90 separate locations across Kuwait as determined in the current work were 17.2, 14.1, and 368Bq/kg, with standard deviations of 5.2, 3.7 and 90Bq/kg for the 238U, 232Th and 40K activity concentrations respectively. Measured isotope ratios for 235U/238U give an arithmetic mean value for all of the samples of 0.045±0.003, consistent with that expected for natural uranium. These results indicate no evidence for a radiologically significant dispersion of additional depleted uranium across the entire State of Kuwait from the 1991 Gulf War.

A study of natural radioactivity in the welding workshops waste

A study of natural radioactivity in the welding workshops waste

Study of Natural Radioactivity, Radon Exhalation Rate and Radiation Doses in Coal and Flyash Samples from Thermal Power Plants, India

Coal is one of the most important source used for electrical power generation. Its combustion part known as fly ash is used in the manufacturing of bricks, sheets, cement, land filling etc. Coal and its by-products have significant amounts of radionuclide's including uranium, thorium which is the ultimate source of the radioactive gas radon and thoron respectively. Radiation hazard from airborne emissions of coal-fired power plants have been cited as possible causes of health in environmental. Assessment of the radiation exposure from coal burning is critically dependent on the concentration of radioactive elements in coal and in the fly ash. In the present study, samples of coal and flyash were collected from Rajghat Power Plant and Badarpur Thermal Power Plant, New Delhi, India. Radon exhalation is important parameter for the estimation of radiation risk from various materials. Solis State Nuclear Track Detector based sealed Can Technique (using LR-115 type II) has been used for measurement radon exhalation rate. Also accumulation chamber based Continuous Radon Monitor and Continuous Thoron Monitor have been used for radon masss exhalation and thoron surface exhalation rate respectively. Natural radioactivity has been measured using a low level NaI(Tl) detector based on gamma ray spectrometry.

Measurement of radioactivity in building materials in Serbia

This work presents a comprehensive study of natural radioactivity in 720 building materials imported in Serbia in 2012. Radioactivity concentrations of 226Ra, 232Th and 40K in the studied samples range from <5 to 4,938, <3 to 763 and <10 to 3,192 Bq kg−1, respectively. The maximum values of 226Ra and 232Th activity concentrations were found in zirconium mineral, while the highest 40K activity concentration was in the feldspar. Based on the obtained radionuclide concentrations, radium equivalent activity, air absorbed dose rate, annual effective dose, external and internal hazard indices, gamma and alpha index due to radon inhalation were evaluated to assess the potential radiological hazard associated with these building materials.

Natural Radioactivity in Tanzania Cements and their Raw Materials

This paper presents the study of natural radioactivity in Tanzania Portland cements and their raw materials. Samples collected as raw materials were pozzolan, sandstone, limestone, clay, gypsum and cement as finished products. The natural radioactivity due to the presence of radium 226 Ra, thorium 232 Th and potassium 40 K were measured by means of gamma spectrometer coupled with HPGe detector. The mean measured activity concentrations of 226 Ra, 232 Th and 40 K in the raw materials range from 2.6 to 93.2, 1.3 to 172.8 and 6.3 to 997 Bq/kg, respectively with higher activity concentrations in pozzolan and lower in gypsum. Activity concentrations of natural radionuclides in raw materials (excluding some materials from Songwe deposits in Mbeya region) are comparative with the worldwide average concentrations of these radionuclides in soil. The average activity concentration of 226 Ra, 232 Th and 40 K in the cements are 46, 28 and 228 Bq/kg, respectively. The calculated values of radiological indices are below 60% of the upper recommended values for building materials. The average annual effective dose to an occupant from use of these materials equals to 0.45 mSv. Average activity concentrations of the mentioned radionuclides in Tanzania cements are in the middle of the variability interval of the national averages.

Study of natural radioactivity and estimation of radiation dose in the environment of Tumkur, Karnataka, India

The activity concentration of (226)Ra, (232)Th and (40)K was measured for soil samples collected from 34 locations of Tumkur District, Karnataka, India, using HPGe detector. The activity concentration of (226)Ra, (232)Th and (40)K varied from 9.6 to 71.6, 12.3 to 333.3 and 194.3 to 1527.7 Bq kg(-1) with an average value of 33.15, 123.01 and 877.76 Bq kg(-1), respectively. The absorbed and annual effective outdoor doses were found to be highest at Ponnasamudra with 258.98 nGy h(-1) and 317.62 μSv and lowest at Sira with 36.42 nGy h(-1) and 44.67 μSv, respectively. The external hazard index ranged from 0.21 to 1.58 with an average of 0.75. It was significant in 11 locations as it exceeded unity.

Sun, Earth, radioactive ore: Common periodicity

The study of natural radioactivity of objects which are able to change their temporal timing feature is presented. It is of interest to compare the latest data on the activity of the Sun and the periodicity of solar neutrinos and the temporal characteristics of the radioactive source. That is, to conduct a search for the possible influence of external sources for radioactivity. There are cycles 5 min, 18 min and 53 min found in solar physics. The cycle of 27 days corresponds to the activity of the Sun. During of the solar activeity these temporal pulsations are lost in a strong variation of solar wind (Neugebauer, NASA). The Stanford University scientists (P. Starrek, G. Valter and M. Vitlend) have found the cycle of 28.4 days as pulsations of the solar neutrinos. Neutrinos come from the depths of the Sun and they tell about the frequency of oscillations of solar bowels. It is also seen online: Kostyantynivska L. V. Solar activity. Search experiment is better to have a known but modified experiment. Experiments on monitoring natural radioactivity and the possible influence from the Sun were previously carried out by measuring the variations of the gamma-ray sample of ore from the TransBaikal uranium deposit; the characteristics of the sample are known. The spectrum of temporal variations in the activity of the sample Zabaikalskaya radioactive ore contains peaks which coincide with the period of natural oscillations of the Sun. The capture cross section of the radioactive heavy deformed nucleus in time decay increases in many orders and is able to interact with the stream of solar neutrinos which are modulated by own oscillations of the Sun. The picks of spectrum of long-period oscillations of the Earth exceed its own contain peaks that match the value with an accuracy of 1% 3% with peaks of its own oscillations of the Sun. The mechanism of excitation of these oscillations is similar to the nature of variations in the activity of a radioactive sample of ore. These effects are included in the mechanisms of interaction of the Earth—the Sun systems and impact on seismicity; search problem of existing natural nuclear reactor inside Earth core.

Study of natural radioactivity in riverbank soils along the Chao Phraya river basin in Thailand

Levels of naturally occurring radioactivity in surface soils along the Chao Phraya river have been investigated. The activity concentrations of radionuclides in the 238U and 232Th decay chains and from 40K were determined through gamma-ray spectrometry measurements made using a hyperpure germanium detector in a low background configuration. Activity concentrations of 238U, 232Th and 40K were found to be 55.3±1.2↔65.2±1.4, 60.7±1.2↔69.1±1.3 and 393±13↔478±16 Bq/kg, respectively. Concerning radiological risk, the absorbed gamma dose rate in air from those soils was estimated to lie in the range 81.6±1.9↔90.4±2.1 nGy/h; the outdoor annual effective dose equivalent was calculated to be 100.1±2.3↔110.8±2.5 μSv/yr. These results are compared with radioactivity measurements with world mean values.

Study of natural radioactivity and the state of radioactive disequilibrium in U-series for rock samples, North Eastern Desert, Egypt

Twenty rock samples collected from North Eastern Desert in Egypt have been investigated. Natural radionuclide contents have been measured by γ-ray spectrometry employing a shielded HPGe detector. The activities of 238U, 232Th and 40K have been determined in Bq/kg dry weight. The absorbed dose rate of γ radiation ranged from 100.48 to 22,140.53 nGy/h. The representative external hazard index values ( H ex) for the corresponding samples were estimated. In the present work, the state of radioactive disequilibrium in the U-series at Wadi Baligh area was studied. The activity ratios between 226Ra/ 214Pb and 214Pb/ 214Bi were measured. The thorium-to-uranium concentration ratios (Clark value) were also estimated.

Some problems in nuclear meteorology

A group of problems associated with radioactive contamination of the atmosphere is discussed. Principal attention is given to the study of natural radioactivity and to those phenomena which are closely connected with meteorology or which assist in the solution of a number of meteorological problems. While setting forth the results obtained thus far, several questions are raised which need investigation.