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This investigation quantifies the activity concentrations of natural radionuclides (226Ra, 232Th, and 40K) in the soils and certain rocks of the Koytash–Ugam Range, Uzbekistan, and assesses their radiological risks. Gamma-spectrometric analysis of soil and rock samples revealed activity concentrations ranging from 456.2 ± 56.0 to 813.9 ± 76.0 Bq kg−1 for 40K, 18.2 ± 6.3 to 70.0 ± 12.0 Bq kg−1 for 226Ra, and 30.1 ± 2.9 to 57.9 ± 10 Bq kg−1 for 232Th. This data indicates a heterogeneous distribution of radionuclides, informing radiation safety and health risk assessments on a global scale. The calculation of radiological hazard indices, including the alpha-index (ranging from 0.09 to 0.35), gamma-index (ranging from 0.40 to 0.73), and both internal (ranging from 0.40 to 0.54) and external (ranging from 0.36 to 0.54) hazard indices, was undertaken to ascertain potential health risks. The radium equivalent activity ranged from 108.4 to 199.3 Bq kg−1, and the absorbed dose rates were 51.0–93.3 nGy h−1 indoors and 96.6–178.2 nGy h−1 outdoors. These metrics underlie the estimated annual effective dose of 536.5–988.5 × 10−3 mSv y−1, highlighting the variability in radiation exposure. Additionally, the potential lifetime cancer risk was projected at 1770.4 to 3262.0 per million, with an annual gonadal dose equivalent of 361.9 to 655.5 μSv y−1, reflecting natural background radiation influence. The results underscore the importance of safe material use in construction and the necessity for routine natural radioactivity monitoring. Radon flux density (RFD) values within acceptable construction limits (26–176 mBq m−2 s−1) suggest the area's suitability for development, considering recommended safety guidelines. This study not only aids local environmental and public health frameworks but also enriches the international knowledge base, facilitating comparative studies for the advancement of global radiation protection standards. Through a detailed examination of radionuclide distribution in an under-researched area, our research highlights the critical need for integrated international approaches to natural radiological hazard assessment. [ABSTRACT FROM AUTHOR]

Radon is a radioactive noble gas omnipresent in the environment, being part of the 238U and 232Th decay chains present in the Earth's crust. The gas can easily leak through the ground but also be present in natural construction materials and migrate into indoor places where it can be a carcinogen when inhaled. Studying the content and removal of indoor radon is crucial for the evaluation and mitigation of its radiological risks to public health. For more than 100 years, the removal by adsorption of the radon has been performed on activated charcoal. There is little progress in the field of radon adsorption at ambient conditions; the main progress is in the use of zeolite materials, having well-defined three-dimensional porous structures and radiation resistance. This study concerns a report on the state of the art of the application of zeolites in radon adsorption. Furthermore, an optimized approach for measuring the radon content in indoor environments and, consequently, its removal has been proposed. Adsorption systems based on zeolites have the potential to replace activated charcoal as a material of choice, allowing to facilitate the development of simple and compact radon adsorption systems. [ABSTRACT FROM AUTHOR]

To establish the radioactivity level of soils and assess the associated radiological impact on residents, 58 samples from the town of Bitola and its environs were collected. After conducting gross alpha and gross beta measurements with a gas-flow proportional counter as a preliminary screening test, subsequent gamma-spectrometry measurements reveal the presence of 40K, 226Ra, 232Th, and 137Cs in the soil samples as radionuclides with the highest impact. The absorbed gamma dose rate, the annual effective dose, radium equivalent activity, external hazard index, gamma index, excess lifetime cancer risk, and annual gonadal dose were calculated using the obtained activity concentrations of the radionuclides. Upon comparison with similar studies conducted in the Balkan countries, the obtained results for radiation hazard indices were found to be the highest in the region. Coloured maps were generated to visually represent the spatial distribution of the absorbed gamma dose rate in air and annual effective dose, clearly indicating the combined influence of geology and human activities, including the nearby thermoelectric power plant operation. [ABSTRACT FROM AUTHOR]

Routine monitoring of internal exposures requires the detection of effective doses of at most 1 mSv per calendar year. For some radionuclides, this requirement cannot be satisfied by a conventional evaluation of the spectra that are gained in alpha or gamma spectrometry. However, since several measurements are conducted per calendar year on a regular basis, a combined evaluation of measurements, i.e. the evaluation of sum spectra, is possible. Additionally, radionuclides that feature several emissions of alpha or gamma radiation allow a combined evaluation of their emissions. Both methods can lead to significantly smaller detection limits as compared to a separate evaluation of spectra in many cases. However, the variation of parameters that influence the evaluation such as the measurement efficiency, abundance and chemical yield requires specific calculations and treatments of the spectra as well as a manipulation of the channel contents: In a combination of emissions, energy regions are summed and evaluated with a combined efficiency that is weighted by the abundances. In a combination of spectra, the channel contents must be scaled by the ratio of the calibration factors before the summation of the spectra. In the routine monitoring of short-lived radionuclides that feature a variety of emissions such as 225Ac, these combinations are particularly effective in reducing the detectable annual effective dose. For alpha spectrometry of 225Ac, both methods applied together can lead to a detectable effective dose of about 1 mSv per year as compared to a dose of about 90 mSv with a conventional separate evaluation. [ABSTRACT FROM AUTHOR]

In this study, a comprehensive investigation was conducted to determine the radioactivity levels of naturally occurring radioactive materials (NORMs) in heap pads/soil and water samples within and around the operational area of Tarkwa Gold Mine in Ghana. Gamma-ray spectrometry was used to determine the activity concentrations of 238U, 232Th, and 40K in heap pads/soil, and 226Ra, 228Th, and 40K in water samples. The average activity concentrations of 226Ra and 228Th in all water samples were below the World Health Organisation (WHO) recommended guidelines for drinking water. Similarly, the average activity concentrations of measured radionuclides in heap pads/soil samples taken from depths of 0–20 cm and 20–50 cm were found to be below the worldwide average reported values. The annual effective dose to the public was estimated to be around 0.16 mSv, which is below the recommended limit. The values of the hazard indices are also below the recommended limits, implying that if heap pads/soils are used for building purposes and construction, they will not pose any significant radiation hazard. The results of this study indicate that radiation levels are within the natural background radiation levels reported in the literature and are consistent with findings from similar studies conducted in Ghana. [ABSTRACT FROM AUTHOR]

Gamma-ray spectrometry-based isotopic composition analysis is a prerequisite for absolute non-destructive assay of Pu by neutron counting or calorimetry. However, gamma-ray spectrometry can be complicated in samples that are heavily shielded or have a high 241Am fraction. Herein, for the absolute non-destructive assay of Pu, a simple yet potent empirical methodology combining neutron multiplicity counting and calorimetry is proposed, which obviates the need for gamma-ray spectrometry-based isotopic composition analysis. The approach includes stepwise correlation between the parameters obtained from neutron multiplicity counting, i.e., α ((α, n) neutron to spontaneous fission neutron ratio), effective mass of 240Pu, and D (doubles neutron rate) with the thermal power output (WPu) due to radioactive decay (measured by calorimetry). Because D and WPu both are governed by the Pu isotopic composition, their correlation should be sensitive to the isotopic information in a given sample. Mandatory correction for the 241Am contribution in WPu was done using the linear plot between its weight fraction and the corresponding α. The proposed methodology was validated by analyzing several PuO2 standards containing high 241Am fraction (0.02–0.09). The measured Pu amounts were within 8 % of the actual values with measurement uncertainties between 8 and 10 %, which shows the potential of the proposed methodology for the assay of samples having high 241Am content or for the quantification of Pu in heavily shielded samples. [ABSTRACT FROM AUTHOR]

This study builds on a preliminary investigation into the efficacy of gamma radiation surveying as a complementary tool for archaeological prospection. Improved surveying and data processing methods were implemented, including the use of a vehicle‐mounted Groundhog surveying system, use of alternative software tools and examination of the impacts of individual radionuclides. The study focuses on a range of targets within Insulae VII, XXXV and XXXIII in Silchester Roman town, Hampshire. Targets of interest included a polygonal temple, a house, ditches (including an Iron Age defensive ditch) and several Roman roads. While the survey revealed no measurable differences in the gamma radionuclide content of less substantial structures (such as the temple and house) and the surrounding soil, it successfully delineated major structures. The Roman roads, Iron Age defensive ditch and potentially an indication of a historic field boundary not present in modern records were clearly visible in the generated visualisations. The roads and field boundary appear as distinct linear features of depleted radioactivity. The location of the Iron Age ditch correlates with an area of elevated radioactivity. Notably, the technique not only successfully identified archaeological features but was also able to indicate differences in the properties of similar targets such as variations in road thickness. Further, the gamma radiation data indicates variations in the local geology attributable to historic changes in land use and geochemical composition. This latest study corroborates the findings of the preliminary investigation, demonstrating replicability, scalability and ability to enhance output data quality. Further research, including sampling and non‐destructive analysis of materials from the site, is needed to better explain observed results. [ABSTRACT FROM AUTHOR]

Burullus lagoon is part of Egypt's protected area network. The lagoon serves as a reservoir for drainage water discharged from agricultural areas, and the lake's sediments provide a unique opportunity to record environmental behavior and reconstruct of the heavy metal contamination history. In the present study, the sediment chronology, sedimentation rates, and metal accumulation fluxes were estimated in four sediment cores using 210Pb dating models to evaluate how human activities have affected the coastal environment. Using the radioisotopes 210Pb and 137Cs, radiometric dating was carried out using gamma-ray spectrometry. At the Egypt Second Research Reactor (ETRR-2), the element concentrations were determined using the instrumented neutron activation analysis (INAA- k0 method). Our findings show that the constant rate of supply (CRS), which has been verified with the peak of artificial radionuclide 137Cs, is the best model performed for the chronology of Burullus Lagoon. The average sedimentation rate, according to 210Pb dating models, is 0.85 cm/year. The large variation in sedimentation rates, especially after the 1990s, is consistent with an increase in the anthropogenic flux of heavy metals. This may be led into a significant environmental problem such as reducing the size of the lake and degrading the quality the water in Burullus Lagoon. Enrichment factor (EF) of the studied elements displayed the following order: Cl > Ca > Na > Br > Zn > Ta > Ti > V > Cr > Sc > Mg > Mn > Fe > Hf which is higher than unity. Furthermore, the Nemerow pollution index (PI Nemerow) revealed that pollution was increasing in the direction of the drains and slightly polluted. Consequently, pollutant indices showed that urbanization and industrial development may have increased the depositional fluxes of the metals in sediments over time. [ABSTRACT FROM AUTHOR]

This study compares the accuracy, efficiency, and reliability of variance reduction (VR) methods for Monte Carlo radiation transport simulations involving wide-area ground plane (i.e., "surface") and buried (i.e., "volumetric") gamma source emissions from environmental soil. The simulation models are idealized external exposure scenarios intended as a basis for deriving site-specific dose-based or carcinogenic risk–based regulatory limits in the radiological site remediation process. These simulations are computationally resource intensive since particle tracks are transported from an extremely large source region to a relatively small detector region. For each simulation, several VR methods are compared with metrics of accuracy, efficiency, and reliability. The MCNP deterministic transport (DXTRAN) VR method was most effective for problems involving sources emitting low-energy gamma rays, and a coupled multicode method was more effective for problems involving sources emitting higher-energy gamma rays that undergo significant attenuation in the soil. [ABSTRACT FROM AUTHOR]

The current study presents the results of the chemical and the radiochemical characterization of phosphogypsum obtained from the former Wizów Chemical Plant in Poland. Phosphogypsum is a residue obtained from phosphoric acid production. Phosphogypsum mainly contains calcium sulfate dihydrate and impurities originating from the source phosphate rock, including toxic trace elements and natural radionuclides. The phosphogypsum stacks occupy a large area and are an environmental issue today. The project “Phosphogypsum Processing to Critical Raw Materials”, currently realized at the Institute of Nuclear Chemistry and Technology, focuses on the use of phosphogypsum from the Polish stacks as material to recover rare earth elements (REEs). The remaining gypsum matrix can be used as an inexpensive material in construction. The chemical and radiological characterization of the radioactive isotopes present in phosphogypsum was performed by using inductively coupled plasma mass spectrometry (ICP-MS) and the gamma spectrometry technique. The radioactivity of the Polish phosphogypsum was then compared with the radioactivity of the phosphogypsum waste present worldwide.

Introduction: This study aims to evaluate the potential radiological hazard associated with the consumption of water and fish products from Ero Dam.Material and Methods: The activity concentrations of 238U, 232Th and 40K in the samples were determined using gamma ray spectrometry.Results: Mean activity concentrations of 238U, 232Th and 40K in water were 8.49 1.38, 4.12 0.40 and 150.99 10.80 Bq/l respectively. In Oreochromis niloticus and Chrysichthys nigrodigitatus mean specific activity were 23.17 7.25, 14.25 , 740.86 Bq/kg and 77.92 , 16.26 1.63, 842.90 Bq/kg respectively. Average annual effective dose for water (Hw) was 1.58 mSv/yr and for fish edible tissue (Hf) 0.16 mSv/yr. Mean concentrations of 232Th and 40K in water are 312% and 1400% higher than guidance levels and mean specific activity for 238U and 232Th in fish were about three orders of magnitude higher than reference values. Mean Hw is about 1500% higher than the reference level and the average Hf for fish is 540% higher than the recommended Hf for natural radionuclides in fish products. Mean ELCR from consumption of water, Oreochromis and Chrysichthys are 1900%, 62% and 131% higher than the world’s average value from carcinogens respectively.Conclusion: Continuous consumption of water and fish products from Ero Dam is associated with potential radiation risks.

Activity measurement of the primary circuit water of fission reactors is one method that can provide early detection of a damaged fuel assembly in the reactor core. This is an important aspect in the safe operation of the reactor and for radiation protection of staff. Radionuclides in the primary circuit water are produced by the activation of stable nuclides and the fission of fissile nuclides, mainly the isotope 235U. In the LVR-15 research reactor, measurement of the activity of the primary circuit water has been regularly undertaken since 1996. A water sample is taken from the primary circuit every week and the activities are measured four days later using gamma spectrometry. The results of these long-term measurements from 1996 to 2022 are presented. The activity time dependences of the individual radionuclides are discussed in relation to fuel assembly damage and for events connected to contamination of the water by objects inserted into the primary circuit during experiments carried out near the reactor core.

The content of uranium 238 (238U) in naturally evolved soils with a meta-morphic and poorly developed profile, later technogenically contaminated by the activity of the former "Kremikovtsi" metallurgical plant, located at the foot of the Buhov uranium ore field, was investigated. A total of six soil profiles were analyzed, incl. five from the industrial site of the combine and one control. Data on uranium content were obtained by two methods - Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), simultaneously with results for over 50 chemical elements, as well as measured by its daughter product - thorium 234 (234Th), determined by gamma spectrometric analysis via multichannel analyzer with high purity germanium detector (HPGe). The results demonstrate that the uranium content of the investigated profiles in single cases exceeds the background norms of 11-173 Bq/kg and is within the range of 50±5 - 180±40 Bq/kg. The maximum values of the studied element are obtained from the coarsest profiles, with the maximum content of coarse sand, which suggests a primary state of uranium in the form of ore minerals or isomorphically included in primary insoluble accessory minerals in the soil of the studied profiles. From the research, the characteristic relationship of the heavy metal with the soil organic matter was not established. Still, an accumulation was observed in the cambic horizons of the metamorphic profiles. A factor for the upward migration and accumulation of uranium is the change of the water-air soil regime and establishment of periodic reducing conditions; as a general conclusion, the natural radionuclide undergoes migration from the surface horizons of the studied Technosols. [ABSTRACT FROM AUTHOR]

The aim of the study was to estimate the degree of anthropogenic risk by evaluating the level of the contamination of sediments collected from the Rybnik reservoir. The results of the determination of radionuclides (137Cs, 40K, 228Th, 228Ra, 226Ra, 210Pb, 238U) and heavy metals (Zn, Cd, Pb, Cu, Cr, Ni) were presented. The Rybnik reservoir is located in a highly urbanised area, the Lower Silesian Voivodeship in Poland. Radionuclides (137Cs, 40K, 228Th, 228Ra, 226Ra, 210Pb, 238U) were measured using gamma spectrometry. The heavy metal (Zn, Cd, Pb, Cu, Ni and Cr) content was determined using an inductively coupled plasma optical emission spectrophotometer (ICP-OES). The classification of sediment pollution was made on the basis of geochemical and ecotoxicological indices. Radioactivity was varied with the highest for 40K (more than 200 Bq·kg−1). The concentrations for the remaining radionuclides were mostly below 20 Bq·kg−1. At the inlet zone (no. 9) an increase in radioactivity of each radioisotope was observed. The values of heavy metals from the lowest to the highest total amount in the sediments were as follows: Cd < Cr < Pb < Ni < Cu < Zn. The sediments of the reservoir are largely contaminated with Cu, but the sediments generally are contaminated to an average degree. Most pollutants accumulate in the inlet zone and near the dam wall. The content of artificial radionuclides, as well as the geochemical and ecological indicators used, can serve as an indicator of the level of anthropopressure in the vicinity of the Rybnik reservoir. [ABSTRACT FROM AUTHOR]

The co-processing of different wastes as fuels in the manufacture of cement clinker not only meets the objectives of a circular economy but also contributes to the reduction in CO2 emissions in the manufacture of Portland cement. However, waste used as alternative fuels, such as sludge or organic-rich residues, may contain naturally occurring radionuclides that can be concentrated during the combustion process. In this study, the presence of natural radionuclides (radioactive series of uranium, thorium, and 40K) and anthropogenic radionuclides (137Cs) in these wastes has been investigated by gamma spectrometry. Possible relationships between the radioactive content and the obtained chemical composition, determined by X-ray fluorescence, have also been studied by applying a principal component analysis (PCA). The results showed that the wastes with the highest radioactive content were sewage sludge with activity concentrations of 238U and 210Pb of 321 ± 38 Bq kg−1 and 110 ± 14 Bq kg−1, respectively. A correlation between radioactive content and Fe2O3 concentration was also observed. The annual effective dose rates to workers for the ashes estimated from the ash content ranged from 0.0033 mSv to 0.092 mSv and therefore do not pose a risk to workers as they are lower than the 1 mSv per year limit for the general public (DIRECTIVE 2013/59/EURATOM). [ABSTRACT FROM AUTHOR]

Introduction: This study aims to evaluate the potential radiological hazard associated with the consumption of water and fish products from Ero Dam. Material and Methods: The activity concentrations of 238U, 232Th and 40K in the samples were determined using gamma ray spectrometry. Results: Mean activity concentrations of 238U, 232Th and 40K in water were 8.49±1.38, 4.12±0.40 and 150.99±10.80 Bq/l respectively. In Oreochromis niloticus and Chrysichthys nigrodigitatus mean specific activity were 23.17±7.25, 14.25±1.60, 740.86±55.00 Bq/kg and 77.92±18.79, 16.26±1.63, 842.90±62.87 Bq/kg respectively. Average annual effective dose for water (Hw) was 1.58 mSv/yr and for fish edible tissue (Hf) 0.16 mSv/yr. Mean concentrations of 232Th and 40K in water are 312% and 1400% higher than guidance levels and mean specific activity for 238U and 232Th in fish were about three orders of magnitude higher than reference values. Mean Hw is about 1500% higher than the reference level and the average Hf for fish is 540% higher than the recommended Hf for natural radionuclides in fish products. Mean ELCR from consumption of water, Oreochromis and Chrysichthys are 1900%, 62% and 131% higher than the world's average value from carcinogens respectively. Conclusion: Continuous consumption of water and fish products from Ero Dam is associated with potential radiation risks. [ABSTRACT FROM AUTHOR]

This study examined the concentrations of 40K, 238U, and 232Th radionuclides and evaluated the possible radiological health risks to medicinal plants found in Ewu, Edo State, Nigeria, using a NaI(Tl) gamma spectrometer. The six selected medicinal plants were Mangifera indica, Dacryodes edulis, Terminalia catappa, Cymbopogon citratus, Anacardium occidentale, and Persea Americana. The results showed that the activity concentrations for 40K ranged from 146.59 ± 4.81 in Persea americana to 296.08 3.42 Bq/kg in Cymbopogon citratus, with a mean of 209.43 ± 5.14 Bq/kg; 238U ranged from 2.25 ± 0.06 to 5.57 ± 0.15 Bq/kg, with a mean of 4.73 ± 0.15 Bq/kg; and 232Th varied from 4.50 ± 0.35 to 12.07 ± 0.57 Bq/kg, with a mean of 8.00 ± 0.40 Bq/kg. The maximum and minimum activity concentrations of both 238U and 232Th were found in Mangifera indica and Cymbopogon citratus, respectively. The calculated average committed effective dose ECED was 0.130 μSv/yr and the excess lifetime cancer risk (ELCR) has a mean of 0.00913 (x10-3). The radiological hazard assessment of the investigated medicinal plants was well within the internationally recommended safe limits of 0.3 mSv/yr and >10-4 for ECED and ELCR respectively. 232Th contributes 54.91% of the total ECED, while 238U contributes the least to 6.35%. 232Th exhibits a very strong, positive, and significant relationship with ECED and the ELCR, and it contributes largely to the ECED and ELCR due to ingestion of the examined herbal plant. Therefore, these medicinal plants are radiologically safe for human consumption. [ABSTRACT FROM AUTHOR]

Hydrogen exploration in the municipality of Maricá (Rio de Janeiro State, Brazil) indicates that important hydrogen and helium gas fluxes are emitted through reactivated faults. The gas concentrations in the soils, and the modelled gas fluxes, are among the most intense measured so far in the world. This exploration has shown new surface expression of hydrogen micro-seeps, observed along reactivated large tectonic accidents instead of "fairy circles", most common proxy for hydrogen systems in cratonic formation. The geology of Maricá, consisting in Neoproterozoic metamorphic rocks without any already documented evidence of hydrogen-prone formations, appears as a very new field of investigation for natural hydrogen. Results indicate the presence of systematic hydrogen saturation of the usual detectors plugged at 80 cm depth, as well as a permanent recharge of hydrogen through time, without relaxation time. Moreover, positive helium anomalies are associated with this hydrogen soil gas, proving the existence of a gas flux coming from deep horizons of the subsurface. This reduces the risk of misinterpretation of surface hydrogen measurement, since the fear of drill bit metamorphism or superficial biological activity inducing hydrogen artefacts is always a possibility. These hydrogen and helium micro-seeps are associated with positive thorium concentration superficial anomalies, as it was already observed in other places associated with hydrogen exudations. We present a model of soil gas behavior, with a differential process of adsorption/desorption of each gas compound (N 2 , O 2 , Ne, H 2 and He), associated with a deep flux of hydrogen and helium. It is possible to assess a quantification of hydrogen flux of 0.32 m3 m−2.day−1. The surface flux ratio He/H 2 is much higher than any published value of generative flux. This may be explained by a subsurface accumulation, where hydrogen is severely altered whereas helium is preserved, increasing the relative proportion of helium versus hydrogen. [Display omitted] • The Marica municipality (Brazil) reveals important potential for natural hydrogen. • Reactivated faults are excellent proxies for natural hydrogen exploration. • Hydrogen seeping out of reactivated faults may be larger than in fairy circles. • Association of hydrogen and helium in soils indicates that no artefact concerns the hydrogen measurements in soils. • Metamorphic formations may be excellent candidates for hydrogen exploration. [ABSTRACT FROM AUTHOR]

During TRIGA reactor operation significant amounts of liquid radioactive waste are generated requiring appropriate management to ensure their safe disposal. Radiological characterization is an important activity needed to accomplish the waste acceptance criteria for different management steps including disposal. The purpose of this paper is to assess the activity concentrations of the ³1H. 383890Sr, 63286328Ni(difficult-to-measure), and gamma emitters (easy-to-measure) radionuclides in liquid radioactive waste generated by the TRIGA reactor operation and to establish a correlation among them to determine the scaling factors for this waste category. The radiological protocols applied for 6328Niand 3890Sr, separation and purification involve extraction chromatography using selective resins, while for H separation the distillation technique was applied. The assessment of gamma emitters was carried out using gamma-ray spectrometry and the detection of ³1H. 3890Sr, and 6328Niwas performed by liquid scintillation counting. The chemical yield of each experiment was determined by measuring the carrier added in each test by inductively coupled plasma optical emission spectrometry. The activity concentrations of 3890Sr, and 6328Niobtained were correlated with the activity concentration of 3860Co for establishing the scaling factor for the liquid radioactive waste stream. There were obtained good correlations but more experimental data are needed to determine the relevant scaling factors for these difficult-to- measure radionuclides. The scaling factors, once established, will improve and optimize the radiological characterization methodology applied for liquid radioactive waste as an easy and rapid method for assessment of concentration activities of difficult-to-measure radionuclides. Until now, no scaling factors data were reported for this liquid radioactive waste generated by TRIGA reactor operated by Institute for Nuclear Research Pitesti. The results obtained in this work represent preliminary data for establishing correlations between difficult-to-measure and easy-to-measure radionuclides and will be used for developing a scaling factor methodology. This will further be used to determine the inventory of difficult- to-measure radionuclides in different waste streams generated by TRIGA operation and decommissioning (foreseen after 2035). [ABSTRACT FROM AUTHOR]

Identification of a failed fuel subassembly due to the dry rupture of its fuel pin in prototype fast breeder reactor is one of the safety protocols to be standardized for its safe operation for which interaction of fission gases with liquid sodium was studied. This paper reports the studies on the feasibility of detection of fission gases in presence of sodium as well as separation of fission gases out of liquid sodium through Ar purge in a prototypical sodium module with 300 mL of Na. The resultant gases were adsorbed on activated charcoal and determined the activity of fission gases using high resolution gamma spectrometry. Quantitative recovery of fission gases from sodium matrix in the range of sub-picogram levels was established. [ABSTRACT FROM AUTHOR]

The Kanyakumari coast is known to be a high background natural radiation area due to the placer deposits of heavy minerals such as ilmenite, monazite, and rutile. The Kanyakumari river sediments that could be the source of the elevated amounts of natural radionuclides in the coastal sands have been studied in this paper. The activity concentrations of primordial radionuclides 226Ra, 232Th, and 40K were determined using high-purity germanium (HPGe) gamma-ray spectrometry. The mean activity concentrations of 226Ra, 232Th, and 40K were found to be 75 Bq kg−1, 565 Bq kg−1, and 360 Bq kg−1, respectively. The mean absorbed dose rate was 395 nGy h−1. Radiological hazard parameters were studied and compared with the world average values. The contribution of 232Th to the total dose rate was found to be higher than that of the two other radionuclides. The high mean ratio of 232Th/226Ra suggested an enrichment of 232Th and the occurrence of 226Ra leaching due to an oxidizing environment. Principal component analysis (PCA) was carried out for the radionuclides in order to discriminate the source of the sediments. This study provides new insights into the distribution of natural radionuclides in sediments of rivers and streams. [ABSTRACT FROM AUTHOR]

An inter-comparison exercise is a quality control tool to standardize a laboratory and was performed between HPU lab at Nuclear Fuel Complex and RPS (NF) lab at Bhabha Atomic Research Centre to determine and compare the concentration of primordial radionuclides in a zircon sample received from Health Physics Unit (HPU), Indian Rare Earth Limited Manavalakurichi weighing 470 g. RPS (NF) lab is annually participating in international inter-comparison exercise conducted by IAEA and is a nodal laboratory for the in-house inter-laboratory comparison exercise. Thus, its values are considered true values. The measured concentrations for 238U and 232Th in zircon sample do not vary considerably as 0.37% variation is observed in true value and measured value of 238U and 0.32% variation is observed in true value and measured value of 232Th. U score is also calculated from the results obtained where it is found to be 0.124 for 238U and 0.195 for 232Th. Trueness and precision tests are also performed, and the laboratory results are found to be "acceptable". It represents that the laboratory performance is evaluated as satisfactory and does not significantly differ from the expected values as per the statistical tools. This ensures that the analytical measurement results of the laboratory are reliable and traceable to reference standard laboratory. [ABSTRACT FROM AUTHOR]

Participation in proficiency tests is an essential part of quality assurance activities for any laboratory involved in radiation metrology. Radioanalytical laboratory, Health Physics Division, BARC, regularly participates in national and international proficiency tests to demonstrate its radiometric capabilities for estimation of low-level natural and anthropogenic radionuclides in environmental matrices. The laboratory has been participating in annual IAEA Proficiency Tests conducted by Terrestrial Environmental Laboratory (TEL), IAEA, for estimation of natural radionuclides as well as fission and activation products in natural and spiked samples. This paper presents the results of estimation of 134Cs and 137Cs (two most important anthropogenic radionuclides that may be released from nuclear reactors during accident conditions) in spiked water samples in last five years of IAEA Proficiency Tests during 2018–2022. All results were lying well within 1σ level of the target values indicating the excellent analytical capability of this laboratory for analysis of 134Cs and 137Cs in aquatic environment. [ABSTRACT FROM AUTHOR]

Natural radioactivity is a public health issue that affects people all around the world. Environmental radioactivity accounts for approximately 87% of the radiation dose received by human beings. The primary external source of irradiation to the human body is gamma radiation emitted by naturally occurring radioisotopes such as 40K and radionuclides from the 232Th and 238U families, as well as their decay products, which exist at trace amounts in all ground formations. The establishment of baseline data for environmental radiological studies is of great importance for the assessment of environmental radiological levels in Uzbekistan and related studies on human health risks. The current study aimed to describe the research state of the art on natural radioactivity in Uzbekistan with emphasis on results obtained during the last 20 years. NaI (Tl) and High Purity Germanium HPGe detectors were employed in most conducted studies. The results showed that data for natural radionuclide activity were below international standards in all but a few areas. The research results of this paper can play a good guidance and reference role in the planning of such research in the future. [ABSTRACT FROM AUTHOR]

Miners, factory workers, traders, end-users, and foodstuff consumers all run the risk of encountering health hazards derived from the presence of elevated levels of radiation in fertilizers, as these groups often come into direct or indirect contact with fertilizers as well as raw materials throughout various linked processes such as mineral extractions, fertilizer production, agricultural practices. A total of 30 samples of various kinds of fertilizer produced in different factories in Dhaka megacity were analyzed to quantify the concentrations of primordial radionuclides using HPGe detector. Among the analyzed samples, average (range) concentration of 40K was found to be 9920 ± 1091 (8700 ± 957–11,500 ± 1265), 9100 ± 1001 (8600 ± 946–9600 ± 1056), 2565 ± 282 (2540 ± 279–2590 ± 285), and 3560 ± 392 (2620 ± 288–4500 ± 495) Bq/kg in the samples of Muriate of Potash Fertilizer, Sulphate of Potash Fertilizer, Humic Acid Fertilizer, and NPKS Fertilizer, respectively. Elevated concentration of 226Ra was found in Triple Super Phosphate Fertilizer with a mean (range) of 335 ± 37 (290 ± 32–380 ± 42) Bq/kg. The higher activity of 40K can be linked to the greater levels of elemental potassium in phosphate fertilizer. Elevated concentrations of radionuclides may also result from variations in chemical processes as well as the local geology of the mining areas where the raw materials were extracted for fertilizer production. Numerous fertilizer brands surpass prescribed limits for various hazardous parameters, presenting significant health risks to factory workers, farmers, and consumers of agricultural products. This study provides baseline information on the radioactivity of fertilizers, which could be used to develop mitigation methods, establish national fertilizer usage limits, justify regulatory frameworks, and raise public awareness of fertilizer overuse. The findings of the study could potentially help to explore the impact of fertilizer on the food chain. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A significant pathway for human exposure to environmental pollutants is the metal transfer from soil to plants. In this study accumulation of different metals was investigated and natural radioactivity levels were measured in the soil--thyme system. It was found that the soil had higher concentrations of Br, Cr, Mn, Ni, and Pb than the world average and P, Ca, and Zn had higher transfer factors. The natural radioactivity level in the soils is similar to the World average. For thyme samples the average values for 226Ra, 232Th and 40K were found as 22.7 ± 10.9 Bqkg-1, 61.3 ± 19.9 Bqkg-1 and 722 ± 391 Bqkg-1, respectively. The health and ecological risks of soil were evaluated. The total hazard index of the child was 1.453 on average, greater than that of the adult (0.175), primarily due to the contribution of Cr. Ecological risk assessed based on various indices indicated that Pb and Ni show environmental contamination risk. Our findings confirm that metal concentrations in plants are influenced by metal concentrations in soil, and that metal interactions are important for pollution risk management. [ABSTRACT FROM AUTHOR]

This article presents two newly developed radiochemical procedures for the destructive analysis of niobium plates irradiated in the core of water-water energetic nuclear reactor (WWER), as well as determination of the specific activity of the generated during the irradiation metastable isotope 93mNb. The procedures were developed and tested using standard samples containing 93mNb and 94Nb. Measurements were made by low energy gamma spectrometry (LEGS) and liquid scintillation counting (LSC) and the obtained data were verified by interlaboratory comparison. All the results were compared with the calculated ones to confirm and evaluate the accuracy and superiority of the two measurement methods. [ABSTRACT FROM AUTHOR]

Abstract The Himalaya, Kohistan, and Karakoram ranges comprise Proterozoic to Cenozoic crystalline complexes exposed in northern Pakistan. Numerous hot springs in the area indicate high subsurface temperatures, prompting a need to evaluate the local contribution of radiogenic heat to the general orogenic-related elevated geothermal gradients. The current study employed a portable gamma spectrometer to estimate the in-situ radiogenic heat production in the Nanga Parbat Massif, Kohistan–Ladakh batholith, and the Karakoram batholith. Heat production in the Nanga Parbat Massif is high, with a range from 0.2 to 10.8 µWm−3 and mean values of 4.6 ± 2.5 and 5.9 ± 1.9 µWm−3 for gneisses and granites, respectively. By contrast, the heat production is low in the Kohistan–Ladakh batholith, ranging from 0.1 to 3.1 µWm−3, with the highest mean of 2.0 ± 0.5 µWm−3 in granites. The Karakoram batholith shows a large variation in heat production, with values ranging from 0.4 to 20.3 µWm−3 and the highest mean of 8.4 ± 8.3 µWm−3 in granites. The in-situ radiogenic heat production values vary in different ranges and represent considerably higher values than those previously used for the thermal modeling of Himalaya. A conductive 1D thermal model suggests 93–108 °C hotter geotherms, respectively, at 10 and 20 km depths due to the thick heat-producing layer in the upper crust, resulting in a surface heat flow of 103 mWm−2. The present study provides first-order radiogenic heat production constraints for developing a thermal model for geothermal assessment.

In this study, a comprehensive investigation was conducted to determine the radioactivity levels of naturally occurring radioactive materials (NORMs) in heap pads/soil and water samples within and around the operational area of Tarkwa Gold Mine in Ghana. Gamma-ray spectrometry was used to determine the activity concentrations of 238U, 232Th, and 40K in heap pads/soil, and 226Ra, 228Th, and 40K in water samples. The average activity concentrations of 226Ra and 228Th in all water samples were below the World Health Organisation (WHO) recommended guidelines for drinking water. Similarly, the average activity concentrations of measured radionuclides in heap pads/soil samples taken from depths of 0–20 cm and 20–50 cm were found to be below the worldwide average reported values. The annual effective dose to the public was estimated to be around 0.16 mSv, which is below the recommended limit. The values of the hazard indices are also below the recommended limits, implying that if heap pads/soils are used for building purposes and construction, they will not pose any significant radiation hazard. The results of this study indicate that radiation levels are within the natural background radiation levels reported in the literature and are consistent with findings from similar studies conducted in Ghana.

The present work is concerned with the fractionations of 238U, 230Th, 226Ra,214Pb, 214Bi, 235U, 228Ac, 208Tl and 40K in sulphuric acid leaching and solvent extraction of uranium, in addition to, thiourea leaching of gold. The activity concentrations of the studied radionuclides indicate that uranium isotopes are highly leachable (89–90%) in sulphuric acid, while 230Th and 208Tl are leached with efficiency of about 76% and 71%, respectively. Less than 35% of 226Ra,214Pb, 214Bi and 228Ac are leached. In solvent extraction processes, uranium isotopes are selectively extracted and stripped. While 208Tl extraction was only 13%. Most of 230Th, 226Ra, 214Pb and 40K could not be extracted at such pH. The leachability of the studied radionuclides was significantly low using acidic thiourea. The dose rate and radium equivalent, in addition to the external and internal hazard indices values for the original sample and the uranium and gold tailings are higher than the recommended maximum values. [ABSTRACT FROM AUTHOR]

The Karnaphuli and Halda rivers play a significant role in the ecological and commercial arena of Bangladesh, but no detailed study on radioactivity in these two rivers sediments is reported elsewhere. The present study measures the concentrations of terrestrial radionuclides in the sediment samples collected from these two rivers by using high-purity germanium (HPGe) γ-ray spectrometry. The concentrations (Bqkg−1) of 226Ra, 232Th and 40K show in the range of 17.63 ± 1.47–38.90 ± 2.50, 27.86 ± 1.76–48.80 ± 2.70 and 324.28 ± 26.83–640.70 ± 42.70, respectively, which is similar to the literature data and world mean value except for four sampling locations (Kalamiabazar, Natun bridge, Rajakhali and Chaktai khal) that shows higher concentrations of primordial radionuclides. These four sampling points are located adjacent to the industrial wastes discharge channels into the Karnaphuli river. In fact, among the thousands of industries located on the bank of the Karnaphuli river, about 200 units were identified as the sources of environmental pollution. To assess human health hazards due to natural radiation, several indicators such as radium equivalent activity (Raeq), external hazard index (Hex) and outdoor annual effective dose equivalent were calculated and compared with the recommended limits. The present results serve as an input to prepare the baseline radioactivity in commercially important river sediments prior to the operation of the first nuclear power plant in the country. [ABSTRACT FROM AUTHOR]

The present work aims to analyze the distribution of radionuclides naturally occurring in the oil shale of the Ama Fatma coastal zone. For this purpose, using gamma-ray spectrometry, we analyzed the activity concentrations of uranium (U), thorium (Th) series, and potassium-40 (K-40) in oil shale samples retrieved from the study area. The concentrations of U-238 ranged from 45 ± 36 to 194 ± 50 Bq.kg−1 and those of Th-232 fluctuated between 1.48 ± 0.92 and 9.47 ± 1.06 Bq.kg−1. The measured concentrations for Ra-226, Pb-214, and K-40 oscillated between 33 ± 5 and 138 ± 9 Bq.kg−1, 18 ± 1 and 68 ± 3 Bq.kg−1, and between 17 ± 4 and 279 ± 16 Bq.kg−1, respectively. The obtained values variation appears to be related to the deposit nature and assimilation processes of appropriate radionuclides rather than the retrieved samples' related depth. The analysis of 232Th/238U and 226Ra/238U allowed an understanding of these radionuclides' behaviors. The ratios 226Ra/238U ranged from 0.56 to 0.74 with a mean value of 0.70 which indicates the existence of disequilibrium in the investigated oil shale samples. This disequilibrium can be attributed to significant differences in the mobility of these radionuclides. [ABSTRACT FROM AUTHOR]

Radionuclides 226Ra, 232Th, and 40K can be found in various concentrations in the surface soil. High concentrations of radionuclides in the surface soil may cause radiological risks. This study investigated natural radioactivity levels and artificial radionuclide (137Cs) levels in the Istanbul University-Cerrahpasa, Avcilar region, Istanbul, Turkey. Radioactivity concentrations were analyzed using the gamma-ray spectrometer. The mean activity concentration of 226Ra, 232Th, 40K, and 137Cs is 28.55, 29.57, 385.72, and 3.09 Bq kg−1, respectively. Radiological parameters radium equivalent activity, absorbed dose rate, annual effective dose equivalent, external hazard index, and excess lifetime cancer risk were calculated using activity concentrations. The radiological parameters values were lower than UNSCEAR values, except for the annual gonadal dose equivalent (approximately 10% higher). There is a strong correlation between radiological parameters and radionuclides. Generally, the activities of radionuclides in the region fall within the recommended limits, thus Istanbul-Avcilar region can be considered safe for settlement. [ABSTRACT FROM AUTHOR]

The exploration of kimberlite pipes is difficult. However, information about their deep structure is necessary for tasks such as prospecting, exploration and development of kimberlite pipes. Therefore, it is necessary to increase the efficiency of deep structure research. In addition, pipes in different territories differ in their properties. The latter requires the study of the peculiarities of the manifestation of pipes in various areas. The Verkhnetovskaya pipe is the only kimberlite object currently known in the Chernoozerskaya area of the Arkhangelsk diamondiferous province. This indicates the need for a comprehensive study of this pipe. The main reason it is difficult to study the pipes of the Arkhangelsk diamondiferous province is the large overburden thickness. In order to increase the efficiency of prospecting, we used a set of methods: microseismic sounding method, passive seismic interferometry, H/V method, gamma spectrometry and emanation mapping. The analysis showed that a new field measurement technique was tested in this research, resulting in more stable data. The main improvement in field measurements is the determination of the optimal accumulation time of microseism when implementing the microseismic sounding method. In addition, the location of the stations in the implementation of passive interferometry made it possible to minimize the influence of the azimuthal distribution of ambient noise sources. The studies made it possible to construct the geophysical image of the investigated pipe and the surrounding medium. As a result, it was shown that the northwestern side has a vertical structure, while according to the drilling data, the side has a uniform slope. In particular, the presence of previously unknown lateral channels was shown. The proposed methodology made it possible to obtain important information with minimal time and technical costs, confirming the applicability of the proposed methodology in the Chernoozerskaya area. [ABSTRACT FROM AUTHOR]

Radioactive elements and their impact on the environment and the food chain, including humans, are a matter of major concern, for which appropriate investigations should be performed. The priority is to examine the concentration of radioactive substances in mineral and bottled spring water. This task aims to analyze the quality of 12 conditioned mineral waters by determining their main radionuclides concentrations, such as 238U, 232Th, and 40K. The identification and the quantification of these radionuclides are carried out by their progeny (except the 40K) by using a NaI(Tl) detector coupled with a multichannel analyzer (MCA) and connected to a computer. The activity measured in all samples varied from 0.95 to 3.38 mBq.L−1 with an average of 1.94 mBq.L−1; from 1.55 to 3.56 mBq.L−1 with an average of 2.46 mBq.L−1; and from 200.68 to 269.19 mBq.L−1 with an average of 236.6 mBq.L−1, for 238U, 232Th, and 40K, respectively. To compare the combined radiological effects of radionuclides present in water, a particular factor Ra(eq) is used. This study showed that the maximum value of Ra(eq) is 27.54 mBq.L−1, which is far below the activity limit of 370 mBq.year−1 set by the Organization of Economics and Development (OECD). Concerning the effective annual dose, the following maximums were measured: 1.61 μSv.year−1, 1.133 μSv.year−1, and 0.925 μSv.year−1 for infants, children, and adults, respectively. These values are even smaller than the dose recommended by the WHO which is 100 μSv.year−1. Regarding the excess lifetime cancer risk index, a maximum of 5.63 × 10−6 is found. This index value is still less than that proposed by James, namely 2.5 × 10−3. Thus, the quality of the studied samples respects the radiological international safety and health limits. [ABSTRACT FROM AUTHOR]

The Himalaya, Kohistan, and Karakoram ranges comprise Proterozoic to Cenozoic crystalline complexes exposed in northern Pakistan. Numerous hot springs in the area indicate high subsurface temperatures, prompting a need to evaluate the local contribution of radiogenic heat to the general orogenic-related elevated geothermal gradients. The current study employed a portable gamma spectrometer to estimate the in-situ radiogenic heat production in the Nanga Parbat Massif, Kohistan–Ladakh batholith, and the Karakoram batholith. Heat production in the Nanga Parbat Massif is high, with a range from 0.2 to 10.8 µWm−3 and mean values of 4.6 ± 2.5 and 5.9 ± 1.9 µWm−3 for gneisses and granites, respectively. By contrast, the heat production is low in the Kohistan–Ladakh batholith, ranging from 0.1 to 3.1 µWm−3, with the highest mean of 2.0 ± 0.5 µWm−3 in granites. The Karakoram batholith shows a large variation in heat production, with values ranging from 0.4 to 20.3 µWm−3 and the highest mean of 8.4 ± 8.3 µWm−3 in granites. The in-situ radiogenic heat production values vary in different ranges and represent considerably higher values than those previously used for the thermal modeling of Himalaya. A conductive 1D thermal model suggests 93–108 °C hotter geotherms, respectively, at 10 and 20 km depths due to the thick heat-producing layer in the upper crust, resulting in a surface heat flow of 103 mWm−2. The present study provides first-order radiogenic heat production constraints for developing a thermal model for geothermal assessment. [ABSTRACT FROM AUTHOR]

To achieve permanent disposal of radioactive waste drums, the radionuclides analysis process is essential. A variety of waste types are generated through the operation of nuclear facilities, with dry active waste being the most abundant. To perform radionuclides analysis, sample pre-treatment technology is required to transform solid samples into solutions. In this study, we developed a dry ashing-microwave digestion method and secured the reliability of the analysis results through a validity evaluation. Additionally, we conducted a comparative analysis of the radioactivity of 94Nb nuclides with and without the chemical separation process, which reduced the minimum detectable activity level by more than 65-fold for a certain sample. [ABSTRACT FROM AUTHOR]

The present study aims to establish a baseline data of natural and artificial radioactivity in soil and phosphate rock samples collected in a prospective phosphate mine of the Hinda District. Samples were measured using an HPGe gamma spectrometer. The mean activity concentrations (Bq kg−1) for 238U, 235U, 226Ra, 232Th, 40K, and 137Cs in soil are 94.87, 12.29, 47, 17, 43, and 1 and 1370.23, 40.16, 922, 70, 103, and 7 for phosphate rock samples, respectively. The obtained mean values were found to be lower than the world mean values for soil samples except for 226Ra and higher for phosphate rock samples. 222Rn activity concentration (Bq kg−1) and 222Rn mass exhalation rate were determined in soil and phosphate rock samples. The radiation hazard indices associated to natural radioactivity were also calculated and found to be lower than the world mean values for soil samples and higher for phosphate rock samples. Strong correlations were found between 226Ra, 222Rn activity concentrations, and 222Rn mass exhalation rates. Based on these findings, soils from prospective phosphate mine are not recommended for construction purposes. Also, phosphate rocks highly contribute to the contamination of the study area. Therefore, in order to protect the population, the recommendations were drawn to strengthen the environmental protection in this mining area during the operation phase of the mine. Precautionary measures such as continuous verification of dose level in the study area are necessary. [ABSTRACT FROM AUTHOR]

Radon emanation power was estimated by applying three different methods. The first was based on measuring radon exhalation rates by closed-loop accumulation method employing RAD7 device. Radon leakage rate was determined by applying two models of fitting the experimental data. Specific activities of 226Ra in soil samples were measured by coaxial HPGe detector (GEM30-70, ORTEC). The second method was indirect gamma-ray spectrometry method which included two separate measurements of counts under the photopeaks of 351.9 keV (214Pb) and 609.3 keV (214Bi). The influence of sample moisture content on radon emanation was demonstrated by both methods. Radon emanation power of the sample with the highest radon exhalation rate was also estimated by 2-month exposure of two radon diffusion chambers equipped with CR-39 detectors. A good agreement among the results was obtained; coefficient of variation was below 10% for the samples employed in the study. Assuming zero volumetric fraction of 218Po in air provided more consistent results. [ABSTRACT FROM AUTHOR]

This study provides a general observation of the status of naturally occurring radioactive materials (NORMs) distribution in mining and industrial areas of Ghana in order to establish regional and national data on NORMs. The study includes data on radioactivity concentrations of U-238, Th-232, and K-40 in soils and for water concentrations of Ra-226, Th-228, and K-40 from various mining, oil, and gas communities, as well as water sources used for crop farming and farmlands. The average activity concentrations of U-238, Th-232, and K-40 in the soil samples were found to be 59 ± 16 Bq/kg, 48 ± 15 Bq/kg, and 286 ± 57 Bq/kg, respectively. The average concentration of Ra-226, Th-228, and K-40 in the water samples were found to be 1.62 ± 0.33 Bq/L, 2.08 ± 0.53 Bq/L, and 22.36 ± 3.44 Bq/L, respectively. The estimated average annual effective doses from external and internal exposure pathways in soil and water samples were 0.09 mSv/y and 0.54 mSv/y, respectively. The total annual effective dose resulting from both exposure pathways was calculated to be 0.63 mSv/y, which is below the 1 mSv/y dose limit recommended by the International Commission on Radiological Protection (ICRP) for controlling public radiation exposure. Based on the radiological hazard indices, the majority of the soil samples were found to be suitable as building materials as their respective indices were below the limits except for two sample locations and the sludge and scale samples. The average Excess Lifetime Cancer Risk (ELCR) value of the water samples was 1.6 times greater than the recommended value of 1.16 × 10−3, presenting a relatively higher risk to the public of developing cancer. No significant regional differences in the levels of radioactive elements. The regression models demonstrate strong interrelationships between the studied elements, with high R-squared values suggesting a predictable nature of one element’s concentration based on others.

Consumption of fish containing elevated levels of radionuclides can lead to undesirable health effects for consumers. People in the Singida Municipality harvest fish from lakes and ponds of granite rocks which are linked with hazardous radioisotopes that may be bio-concentrated by fishes they consume. Currently, no study has ascertained the levels of radioisotopes in fish from these environments. This study was carried out to analyse the radioactivity levels of 226Ra, 228Ra and 40K isotopes in order to assess the radiological risk associated with Tilapia fish consumption and its environment in Singida Municipality. Some 51 samples, which included water (20), sediment (20), Nile tilapia (8) and Manyara tilapia (3), were randomly sampled and composited; then, they were analysed using a high-purity germanium (HPGe) detector, between May and June 2022. The results revealed that (i) the activity levels of 228Ra were below the detection limit for fish and water samples, while in sediment, the combined activity of 228Ra was within the acceptable international levels; (ii) the mean activity concentrations of 226Ra and 40K in all other samples were within the recommended levels; (iii) the activities of radionuclides in the samples analysed were high in sediments, followed by fish, and lastly water; (iv) the bioaccumulation results show that only 40K was bio-accumulated (with 1.26 in Nile tilapia), while other radionuclides (226Ra, 228Ra) were not bio-accumulated; (vi) the radionuclide transfer from water to fish was higher compared to the radionuclide transfer from sediment to fish; (vii) the human effective doses due to consumption of Nile tilapia and Manyara tilapia were 0.00973 and 0.005 mSv/y, respectively, which is below the 1 mSv/y international limit. These findings therefore show that the current levels of radioactivity in fish in the study area do not pose a significant radiological risk to fish consumers. However, more studies on other types of fish are recommended.

The co-processing of different wastes as fuels in the manufacture of cement clinker not only meets the objectives of a circular economy but also contributes to the reduction in CO2 emissions in the manufacture of Portland cement. However, waste used as alternative fuels, such as sludge or organic-rich residues, may contain naturally occurring radionuclides that can be concentrated during the combustion process. In this study, the presence of natural radionuclides (radioactive series of uranium, thorium, and 40K) and anthropogenic radionuclides (137Cs) in these wastes has been investigated by gamma spectrometry. Possible relationships between the radioactive content and the obtained chemical composition, determined by X-ray fluorescence, have also been studied by applying a principal component analysis (PCA). The results showed that the wastes with the highest radioactive content were sewage sludge with activity concentrations of 238U and 210Pb of 321 ± 38 Bq kg−1 and 110 ± 14 Bq kg−1, respectively. A correlation between radioactive content and Fe2O3 concentration was also observed. The annual effective dose rates to workers for the ashes estimated from the ash content ranged from 0.0033 mSv to 0.092 mSv and therefore do not pose a risk to workers as they are lower than the 1 mSv per year limit for the general public (DIRECTIVE 2013/59/EURATOM).

For future low-background particle physics experiments, it will be essential to assay candidate detector materials using an array of assay techniques. To minimise the risk of sample contamination whilst moving between assay techniques, it is also sensible to minimise the distance between assay stations, particularly for non-destructive techniques where the sample may end up being installed into an experiment. The Boulby UnderGround Screening (BUGS) Facility comprises an array of germanium detectors, two XIA UltraLo-1800 surface-alpha counters, two radon emanation detectors and an Agilent ICP-MS system. This article describes each of these systems.