Gamma Scintillation Spectrometer Research Articles

Determination of natural radionuclides and heavy metal concentrations in the groundwater and adjacent areas of the Kattakurgan reservoir, Uzbekistan

Abstract We conducted a comprehensive assessment of the Kattakurgan reservoir, alongside adjacent wells and boreholes, to measure the concentrations of natural radionuclides, heavy metals, and associated radiological hazards. Using NaI(Tl) crystal scintillation gamma spectrometers, we determined radionuclide levels in water and sediment. Inductively coupled plasma mass spectrometry (ICP-MS) was employed for heavy metal analysis. Our results showed radionuclide concentrations in reservoir water for 226Ra (0.8 Bq/L), 232Th (0.4 Bq/L), and 40K (0.4 Bq/L) were within the limits set by the World Health Organization (WHO). In contrast, deep well water samples showed elevated 226Ra concentrations (1.5 Bq/L). Sediment samples’ radionuclide levels were in line with UNSCEAR guidelines. Barium was the most notable heavy metal, with a concentration of 68.08 μg/L. While most radiation hazard indices remained within safety limits, the gamma index recorded a value of 1.057 Bq/kg. Our research provides valuable data for water quality assessment. The methods described can be applied to other reservoir studies. Regular monitoring is recommended for continuous safety evaluation, and further studies on biotic samples are suggested to enhance understanding of the reservoir’s ecosystem health.

Evaluation of soil radioactivity in the areas of underground nuclear explosions at the Pomuk gas field site in Uzbekistan.

This study investigates soil radioactivity at the Pomuk gas field in Uzbekistan, a region with history of underground nuclear activity. Using a NaI (Tl) scintillation gamma spectrometer, soil samples were analyzed for concentrations of 232Th, 226Ra, 40K, and 137Cs. Concentrations were found to be in the range of 19.0-31.0 Bq/kg for 232Th, 12.0-32.0 Bq/kg for 226Ra, 450.0-634.0 Bq/kg for 40K, and 2.4-11.0 Bq/kg for 137Cs. Surface radon flux density was measured using a coal sorbent-based passive method, with values ranging from 26.1 to 79.0 mBq/m2s. Mean activity values for radium equivalent (Raeq) and gamma representative level index (Iγ) were calculated to be 75.2-96.5 Bq/kg and 0.3-0.4 Bq/kg, respectively. The absorbed airborne gamma dose rates (GDR) varied between 41.0 and 52.0 nGy/h, while annual effective dose rates (AEDR) were 0.3-0.4 μSv/year. The radiological risk assessment indicates the area is within safe limits for the population and environment, providing a foundation for future radiological monitoring programs.

Quantification of radiological hazards associated with natural radionuclides in soil, granite and charnockite rocks at selected fields in Ekiti State, Nigeria

Assessment of activity levels of radionuclides that exist in soil, granite, and charnockite rock samples is very crucial because it exhibits an enhanced elemental concentration of uranium (U) and thorium (Th) contributing higher natural background activity than usual in the environment and it may cause health risk to human health through the external and internal exposure. This study determined the radioactivity levels of 238U, 232Th, and 40K radionuclides in soil, granite, and charnockite rock samples collected from selected fields in Ekiti State, Nigeria using Caesium iodide CsI(Tl) scintillation gamma spectrometer. It also evaluated indices of the radiological parameters consisting of radium equivalent activity (Raeq), absorbed dose rate (DR), annual effective dose equivalent (AEDE), internal hazard index (Hin), and excess lifetime cancer risk (ELCR). The calculated average activity concentrations of 238U, 232Th, and 40K are 30.40 ± 0.71 Bq kg−1, 3.31 ± 0.05 Bq kg−1, and 222.25 ± 14.72 Bq kg−1, respectively, which were lower than their respective world average values. Comparatively, potassium concentrations in these collected samples have a higher value than concentrations of uranium and thorium (40K > 238U > 232Th). All the evaluated values of the radiological parameters (except DR) of the appraised radionuclides were below the global permissible limits. The granite rocks, charnockite rocks, and soils from Ekiti State in Nigeria do not pose any hazardous risk to humans, but continued monitoring is necessary when these materials are used as building materials, which cause long-term radiation exposure.

Radioactivity and Heavy Metal Accumulation in Surface Sediment from the West Aegean Coast

ABSTRACT Sediment quality can be assessed by analyzing radionuclides and heavy metals from pollution sources. These substances also provide insight into sediment structure and marine pollution. The aim of this study was to evaluate the risk of radiation and heavy metal accumulation in İzmir Bay by taking into account both lithologic and anthropogenic factors. Sediment samples were collected from İzmir Bay on a seasonal basis. Gamma-ray spectrometry techniques were used to determine radionuclides in the sediment using a NaI (Tl) scintillation gamma spectrometer. X-ray fluorescence spectrometry (XRF) was employed to measure heavy metal concentrations in the samples. Mean concentrations of 232Th (43.6 Bq/kg), 226Ra (35.3 Bq/kg), 40K (699.2 Bq/kg), and heavy metals Fe (13408.3 ppm), Al (16891.6 ppm), Mn (517.3 ppm), Zn (59.8 ppm), Cr (96 ppm), Ni (31.6 ppm), and Pb (31.8 ppm) were determined in the surface sediment. The elevated levels of both radionuclides and heavy metals were attributed to industrial accumulation and sedimentation patterns in the bay. The study highlights the importance of considering both geological structures and environmental risks in assessing sediment quality.

Radioactivity of metallurgical enterprises waste

Abstract. Problem. The problem of obtaining environmentally friendly materials is especially relevant when using the wastes that concentrate natural radionuclides (NRN) dangerous for public health. The concentrators of radionuclides include dump and granular blast-furnace slags. Goal. The purpose of the work is to determine the radionuclide composition of the fractions of dump and granular blast-furnace slags from Ukrainian enterprises, their compliance with the radiation safety standards of Ukraine and international radiological indicators, and to identify the factors that determine the level of natural radioactivity of the slags. Methodology. The specific activity of natural slag radionuclides was determined by the gamma spectrometric method on a SEG-001 scintillation gamma spectrometer. The mineral composition of the crystalline component of the slag was determined using X-ray phase analysis performed on a Siemens D500 powder diffractometer. The elemental composition of blast furnace slag was determined by the method of electron-probe microanalysis on a JSM-6390 LV scanning electron microscope with an INCA micro-X-ray analysis system. The particle charge and electrokinetic potential were determined during macroelectrophoresis of suspensions. Results. The blast-furnace slag contains natural radionuclides: 226Ra, 232Th and 40K. The content of radionuclides varies by waste fractions. According to the contribution to the total activity value, NRN can be arranged in a row: 40К > 226Ra > 232Th. The most radiation-clear is the fraction > 20 mm of the “Zaporizhstal” dump slag, the radioactivity of the fractions 1.25‒2.5 mm for DMC, 5‒10 and 0.63‒1.25 for MMC and the “ArcelorMittal” granulated slag is increased. All investigated slags belong to the first class of radiation hazard (Сef 370 Bq/kg) and can be used in construction without restrictions. Originality. All investigated slags correspond to international radiological indicators: Raeq 370 Bq/kg, radiation hazard indices are Iγ, Iex, Iin and Iα 1, which indicates that there is no danger of increased gamma radiation and emanation of radon and the daughter products of its decay into the room air. The concentration of radon indoors does not exceed 200 Bq/m3. For the average sample and slag fractions <2.5 mm of “ArcelorMittal”, the activity utilization index which determines the safety of practical waste use is overestimated; the absorbed dose rate in the open air and the annual effective equivalent dose are higher than the world average values, they are, respectively, 58 nGy/h and 0.07 mSv, but at the same time below the value recommended by the IAEA for the population of 1 mSv/year. The excess lifetime carcinogenic risk for dispersed fractions of “ArcelorMittal” slag is higher than the world average: 0.29·10–3, but below the 0.05 limit set by the International Commission on Radiation Protection. A direct correlation between the acidity of the slag fractions and the increase in radiological parameters was determined. Practical value. An attempt has been made to relate the radioactivity of blast-furnace slag with the NRN sorption on the negatively charged surface of slag particles, which is more reliable for amorphous sorption-active granular slag.

Novel metallic Bi-Pb–Cd-Ag alloys for shielding against neutrons and gamma rays

Obtaining high-performance shielding alloys against mixed neutrons and γ-rays is vital in the field of nuclear radiation. In this work, shielding Bi-Pb–Cd-Ag alloys with superior thermal neutron shielding and high ability to attenuate γ-rays were developed. The microstructure, melting behavior, and mechanical properties of the prepared alloys were characterized. The γ-rays mass attenuation coefficients () were obtained using WinXCom program in the energy range of 0.015–15 MeV. The shielding parameters including atomic and electronic cross-sections (σ a and σ e), effective atomic number (Z eff ), effective electron density (N eff ) were calculated. The exposure buildup factor (EBF) using a geometric progression (GP) fitting method was estimated. The experimental measurements were carried out at 662 and 1173, 1332 keV of 137Cs and 60Co isotope sources, respectively using a scintillation gamma spectrometer NaI(Tl) detector. The calculated results of WinXCom are consistent and in agreement with the experimental values of The macroscopic effective removal cross-section () of the samples for fast neutrons were calculated. Also, the attenuation of thermal neutrons through the prepared alloys has been investigated. It was found that the alloy containing 30% Cd complies with the compromise between superior thermal neutron attenuation besides its superior ability to attenuate γ-rays with good mechanical strength and high ductility.

Universal calibration of a scintillation spectrometer with a NaI(Tl) detector when measuring 137Cs activity in counting samples of arbitrary density and volume

The article proposes an empirical method for constructing a universal calibration for a scintillation gamma spectrometer, which allows determining the activity and specific activity of 137Cs with an accuracy of no more than 15% in counting samples of arbitrary density and volume in cylindrical containers with a volume of 250 ml and 500 ml. To construct calibration ratios, measurements of 137Cs sample media prepared on the basis of materials of different densities (quartz sand, plastic granules and sawdust) were performed. The calibration was carried out by preparing samples from the listed materials with a volume of 50 to 250 ml in increments of 50 ml for a 250 ml container and 100-500 ml in increments of 100 ml for a 500 ml container. Along with taking into account the volume of the counting sample, its weighing was also carried out. The result of the measurements performed for each material was the ratio of the activity of the counting sample to the counting intensity in the 137Cs window, depending on the volume. The universal calibration factor is obtained by taking into account the counting rate from the mass and volume of the sample for the corresponding measuring vessel.

APPLICATION OF A SCINTILLATION GAMMA-SPECTROMETER FOR DETERMINATION OF RADON CONTENT IN WATER

Experimental studies have been carried out to determine the sensitivity of a mobile scintillation gamma-spectrometer to radon-222 in mineral water samples for the selected measurement geometry and the minimum measurable activity of radon-222 in such samples. The measurement results of radon content in mineral water samples obtained using such gamma-spectrometer are presented too.

Performance stabilization of scintillation spectrometers for aerosol monitoring

The article presents the results of the development of the scintillation gamma spectrometers, based on NaI(Tl), LaBr3 or SrI2(Eu) scintillators, intended for aerosol monitoring over a wide temperature range. The stabilization of the characteristics is provided by applying various stabilization methods of the spectrometric chain. The estimation of the impact of those methods on the stability of the characteristics of the developed radiation spectrometer is provided.

The Effect of an Iodine-Free Diet on the Pharmacokinetics of the 211At Preparation

The pharmacokinetics of the Astatine-211 radiopharmaceutical was investigated after a single injection in male SD (Sprague–Dawley) rats that had normal and iodine-free diets. Twelve groups of SD male rats were examined in the study. The tested drug was intravenously injected into the tail vein of the animals once at a volume of 10 mL/kg and dose of 100 μCi per animal. In the study, the animals were subjected to necropsy at specific time points with retrieval of the organs and tissues for further analysis of the activity of the samples using a well-type scintillation gamma spectrometer. It was found that the 211At absorption by the thyroid in the male rats that had an iodine-free diet was greater than in the rats that had a conventional diet.

Method for performing rapid radiation surveys of the water areas at shore bases of the naval fleet using submersible gamma spectrometers

A method of performing radiation surveys of the water areas at shore bases of the naval fleet using underwater scintillation gamma spectrometers is presented as an example of work performed in the waters near the temporary storage site for radwastes and spent fuel in Gremikha. This method makes it possible to record in situ from a surface ship as well as underwater manned or unmanned vehicle the content of radionuclides in sea water. In contrast to conventional methods of monitoring the radiation conditions by means of dosimetric surveys and sampling, submersible spectrometric systems make it possible to detect and identify rapidly the source of radioactive contamination in water and bottom deposits and to determine it size, intensity, and isotopic composition. Appropriate software is used to construct from the survey results cartograms of the contamination in the regions examined, identify pathways for radionuclides to enter the waters, and evaluate the total activity of the bottom deposits.

Measurements of Gamma-Ray Production Cross Sections and Spectra in Inelastic Interaction of 14 MeV Neutrons with Nuclei C, O, Mg, AI, Fe, Cu, Zr, Mo, W and Pb

The results of new measurements of gamma-ray production cross sections and spectra in inelastic interaction of 14 MeV neutrons with nuclei C, O, Mg, Al, Fe, Cu, Zr, Mo, W, Pb are discussed. The measurements were carried out for the gamma-ray energy interval of 0.5-14 MeV using the pulsed neutron source and scintillation gamma-spectrometer combined with the time-of-flight technique. Parameters of the used samples, the geometry and conditions of measurements are described. The corrections connected with the multiple scattering of neutrons and gamma-rays in samples and the contribution of gamma-rays from the neutron target are taken into consideration.The total and differential gamma-ray production cross sections are given for all samples together with their uncertainties. The estimated uncertainty of the total production cross sections is about 9% for the confidence probability level of 0.95.

Effect of scattered radiation on the shape of the instrumental line of a scintillation gamma spectrometer

Effect of scattered radiation on the shape of the instrumental line of a scintillation gamma spectrometer

A radiochemical assay for heme synthase activity.

A radiochemical assay for heme synthase (ferrochelatase) activity is described in this report. The principle of the assay is to measure the incorporation of 59Fe, added to the reaction flask with a known amount of iron, into heme. Iron is maintained in the ferrous state, and oxygen is excluded from the flask during the incubation of the substrates with enzyme. Labeled heme product is extracted by solvent partitioning and counted in a gamma scintillation spectrometer. The assay can detect picomole amounts of product and is most useful when low levels of heme synthase activity are present.

Liquid-Scintillation Counting of [57Co]—Application to the Radioassay of Vitamin B12

Abstract Cobalt-57 can be measured in a liquid scintillation counting system. We describe the calibration of such a system for this gamma emitter. The counting procedure has been used in the radioassay of vitamin B12. Results of assays for which counting of bound radioisotope was done in a gamma scintillation spectrometer and in a liquid scintillation counter show that either counting system can be used for the measurement of [57Co].

Working standard of the unit of intensity of exposed dose of gamma radiation over the range 3nA/kg to 3pA/kg (?10?0.1? R/sec)

>Translated from Izmer. Tekh.; 16: No. 8, 68-70(Aug 1973). The design and performance of a lead-shielded NaI(Tl) scintillation gamma spectrometer for measuring low-intensity gamma spectra and subsequent conversion to exposed dose are discussed. Spectrometer calibration, efficiency, and errors are discussed and the method for conventing the gamma spectra to dose is described. (WHK)

Determination précise de quelques périodes radioactives

For accurate determination of the half life of radionuclides we used three methods: differential ionization chambers, Proportional 4 π beta counter, gamma scintillation spectrometer. The half lives of the following radionuclides were determined: 24Na, 54Mn, 56Mn, 60Co, 90Y, 95Nb, 125I, 131I, 133Ba, 144Ce, 198Au, 203Hg and 204Tl.

Determination of the burnout of a fuel element from the icebreaker lenin on the basis of Cs137 activity without chemical separation

It is proposed to use a scintillation gamma spectrometer for determining the absolute values of fuel element burnout. The burnout is determined from the intensity of the gamma lines of the Cs 137 (Eψ = 0.66 MeV) accumulated in the fission products. The report gives the results of investigations of U235 burnout as a function of distance along a depleted fuel element of the reactor on the icebreaker Lenin. The research was conducted in the hot laboratory of the I. V. Kurchatov Atomic Energy Institute.

Computer correction for shifts in gain and baseline in gamma-ray scintillation pulse height spectra

In the quantitative analysis of multicomponent pulse height spectral data, precision depends upon 1. the statistical variation inherent in the radioactive decay process, 2. statistical variations in the detection process and 3. instrumental variations. The nature of the statistical variations in categories 1 and 2 are well understood and easily considered in the estimation problem. Category 3 variations are more difficult to evaluate and correct. The main variations observed in this category are of gain and baseline. In order to determine the instrumental conditions that prevail at the time of measurement, the spectrum of a standard ( 44Ti) was obtained immediately before experimental spectra were obtained. This standard spectrum was then compared to a reference standard spectrum to obtain estimates of gain and baseline status, and appropriate corrections were applied to the experimental data. This technique, which can correct for shifts in both baseline and gain in excess of one channel (with respect to channel 256 of a 256-channel system), is capable of making corrections of as little as 1 20 of a channel. Improvement in the resultant quantitative estimation of the constituents of multicomponent pulse height spectra is demonstrated. The method should provide the basis of a good quality control procedure for the scintillation gamma spectrometer, provided the spectrometer data can be conveniently entered into a computer.

The determination of caesium-137 in irradiated uranium by using the ring-oven technique and gamma-ray spectrometry

A ring-oven method is described for determining cesium-137 in irradiated uranium solutions. A small drop of the solution is placed on a pre-formed ferric hydroxide precipitate situated at the center of a filter-paper. The paper is positioned on a ring oven, and washed with ammonia solution and water. The cesium-137 migrates to the ring zone, and the other fission products and uranium stay in the center of the paper. The cesium-137 in the ring zone is determined by using a gamma scintillation spectrometer. The method compares well with an ion-exchange procedure. (auth)