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In this study tritium exposure was assessed through urine samples analysis by the determination of tritium concentration and effective dose of selected 25 laboratory radiation workers in non-nuclear power plant (non-NPP) facility and 15 people of general public in Jakarta. The samples were mixed with activated charcoal, filtered, and distilled before analysis using liquid scintillation counter. It is revealed that the concentration of tritium levels in urine varied substantially depending not only on the job category but also their water intake, metabolism, and environment. These findings are important as reference data for evaluating the radiological impact on the population from future tritium contamination in Indonesia. [ABSTRACT FROM AUTHOR]

Abstract Studying groundwater renewal time is a valuable tool to deepen the comprehension of sustainable groundwater resources specific to arid regions. Tritium is a radioactive isotope of hydrogen often used as an environmental tracer to study groundwater renewal time. The present work reports groundwater renewal times by the environmental tracer tritium to understand sustainable water resources in arid regions. First, groundwater samples were collected from wells in northeastern arid regions of Saudi Arabia. Then, an electrolysis process was employed to significantly increase the tritium level from twenty-five to thirty times the original concentration. Subsequently, the enriched water was analyzed using a liquid scintillation counter under optimized measurement conditions to determine the tritium concentration precisely. Two internationally recognized tritium laboratories conducted independent assessments to validate the estimated tritium levels. The verified tritium concentration was then used to estimate the groundwater renewal time using the Morgenstern and Pimenta curves. The results suggest that most of the monitored wells in the surveyed areas are more than a century old. Conversely, a few monitoring wells exhibit renewal times of several hundred years and may be considered nonrenewable water sources. These studies help to understand the geochemical characteristics of arid regions to ensure the sustainable management and protection of groundwater resources.

For the rapid analysis of the amoun of 90Sr in medical yttrium[90Y] chloride solution， 90Sr was separated from the yttrium[90Y] chloride solution by DGA resin,and measured by a liquid scintillation counter. The acidity and volume the elution were also studied. The results show that this method provides stable and reliable detection results，good linearity，and fully meets the detection requirements of 90Sr with a limit of

In this study, an assessment of Radon concentration in some selected water sources from Kiyawa town, Kiyawa local Government area, Jigawa state, Nigeria was conducted. The results obtained show that the concentrations of Radon in the water samples ranged from 32.152 to 43.891 Bq/L, with mean values of 37.78 Bq/L and 35.13 Bq/L for well and borehole water respectively. These results were compared with the world average Maximum Contaminant Level (MCL) of 10 Bq/L set by the World Health Organization (WHO), and it was observed that 60% of the recorded Radon concentrations, alongside the mean values for both water types, exceeded the WHO's recommended MCL of 10 Bq/L, as well as the MCL of 11.1 Bq/L set by the United States Environmental Protection Agency (USEPA) in 1991. However, all mean values were below the recommended action level of 100 Bq/L set by the European Commission (2001/928/Euratom) for public water supplies, and WHO in 2008. Also, all the mean values of the annual effective doses exceeded the recommended level of 0.1 mSv/year set by the WHO. Consequently, it is recommended that the inhabitants of Kiyawa town boil their water, regardless of its source, before drinking to reduce Radon concentrations in the water.

Studying groundwater renewal time is a valuable tool to deepen the comprehension of sustainable groundwater resources specific to arid regions. Tritium is a radioactive isotope of hydrogen often used as an environmental tracer to study groundwater renewal time. The present work reports groundwater renewal times by the environmental tracer tritium to understand sustainable water resources in arid regions. First, groundwater samples were collected from wells in northeastern arid regions of Saudi Arabia. Then, an electrolysis process was employed to significantly increase the tritium level from twenty-five to thirty times the original concentration. Subsequently, the enriched water was analyzed using a liquid scintillation counter under optimized measurement conditions to determine the tritium concentration precisely. Two internationally recognized tritium laboratories conducted independent assessments to validate the estimated tritium levels. The verified tritium concentration was then used to estimate the groundwater renewal time using the Morgenstern and Pimenta curves. The results suggest that most of the monitored wells in the surveyed areas are more than a century old. Conversely, a few monitoring wells exhibit renewal times of several hundred years and may be considered nonrenewable water sources. These studies help to understand the geochemical characteristics of arid regions to ensure the sustainable management and protection of groundwater resources. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Isotopes is the property of Journal of Isotopes Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Assessing groundwater residence time in aquifers of arid regions by analyzing natural radionuclides is crucial for predicting water contaminants, understanding groundwater system dynamics and ensuring sustainable water utilization. This study focuses on the evaluation of groundwater residence time in northeastern Saudi Arabia using tritium as a tracer, where water samples were collected from monitoring wells. Due to the low levels of tritium, the water was reduced twenty to thirty- times from its initial values through the electrolysis process. The enriched samples were meticulously analyzed using a liquid scintillation counter under optimal conditions to determine tritium concentrations. Validation from two international commercial tritium laboratories further confirmed the estimated tritium concentrations. The tritium concentrations were then employed to estimate the groundwater age for each monitoring well. Comparative analysis with international datasets suggests that the collected groundwater in the studied areas is likely over a century old. Notably, groundwater ages display significant variations in different locations, even within the same aquifer. These disparities stem from differences in water flow dynamics, recharge rates, and the geological composition of the rocks and sediments through which the water travels. In contrast, water from selected monitoring wells exhibited an age exceeding a few hundred years, categorizing it as ‘dead water’ due to an extended residence time in the aquifer. This research contributes valuable insights into the longevity of groundwater resources, aiding in formulating sustainable water management strategies in arid regions.

Radon (222Rn) is radium's immediate radioactive decay product (226Ra) in the uranium decay series. Radon is classified as a group 1 carcinogen due to its hazard to human health, and the evaluation of radon concentrations has become essential. Therefore, an advanced method was applied to a liquid scintillation counter (Hidex 300SL) to measure the radon concentration in groundwater. The estimated radon concentration was between 0.1 and 3.20 Bq/L, with an average of 0.96 Bq/L and with a standard deviation of 0.82 Bq/L. The estimated radon concentrations are in the safe range recommended by the United States Environmental Protection Agency (USEPA) and European Atomic Energy Community (EAEC). However, the values are far below the safe range set by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCARE), European Commission (EC), and World Health Organization (WHO) standards. Nevertheless, the estimated radon concentration by this advanced application ensured no risk of radon exposure from the groundwater of the tested area. [ABSTRACT FROM AUTHOR]

During the operation of the reactor, a large amount of tritium is released into the surrounding air through the waste gas treatment system and the plant ventilation system. Tritium is very easy to replace hydrogen in water molecules, and can enter the human body through breathing, resulting in internal radiation hazards. Therefore, it is necessary to study the measurement of tritium in ambient air. At present, there is no national or industrial standard for the measurement of tritium in air. In this paper, the liquid scintillation counter was used to measure the activity concentration of tritium in air. It is found that the detection limit of the activity concentration of tritium in the air mainly depends on ambient temperature, relative humidity, sample amount, detection efficiency of the instrument, background count rate of the instrument, measurement time, etc. Among them, ambient temperature and relative humidity are inherent characteristics of air samples. Therefore, in order to reduce the detection limit and shorten the measurement time as much as possible, three aspects must be considered which is reducing the background count rate, improving the detection efficiency and increasing the sample volume. Possible approaches include selecting background water and scintillation fluid with the lowest possible counts, selecting the appropriate counting area, and optimizing the mixing ratio of sample and scintillation fluid. In order to reduce the effect of water and scintillation fluid on the background, 11 different sources of background water and 3 types of scintillation fluid were selected for testing. The samples were prepared according to the ratio of 8 mL of water to 12 mL of scintillation fluid, and the long-term counting measurement was carried out after being stored in the dark for 24 h. The measurement results show that the count rate range of the background water sample varies from 2.373 min-1 to 3.441 min-1, and the difference between the maximum value and the minimum value is 1.068 min-1, which also shows that the selection of the background water sample is very critical. For three scintillation fluids including Gold Star Quanta, OtpiPhase HiSafe 3 and UItima Gold LLT, there is no significant difference in background and detection efficiency.In order to further reduce the detection limit, a figure of merit (FOM) was introduced, which is the ratio of the square of the detection efficiency of the radionuclide of interest to the background count rate. To maximize FOM, it is necessary to reduce the sample background count rate while maintaining a high detection efficiency, which can be achieved by optimizing the count area. By changing the lower threshold (LL) and upper threshold (UL) of the pulse height discriminator, a series of counted regions and the corresponding FOM can be obtained. The optimal count interval is 0.35-4.35 keV, which maximizes FOM. For full spectrum counting, the sample detection efficiency is 29.27% and the background counting rate is 6.53 min-1, from which the FOM is calculated to be 131.2. After optimizing the counting area, although the detection efficiency is only 25.62%, the background is only 2.42 min-1, and the FOM reaches 271.2. The optimization of the counting interval reduces the detection efficiency from 29.27% to 25.62%, a decrease of 12.47%. But there is an even bigger reduction in background, at 170%. In terms of optimizing the combination of water and scintillation fluid, samples were prepared and measured with water contents of 35%, 40%, 45%, 50%, and 55%, respectively. The comparison results show that when the water content is 40% and 45%, the quality factor of the measurement system reaches the maximum, and the detection limit reaches the minimum. Tritium in air was measured under optimized conditions. The detection limit of typical samples is 20 mBq/m3, and the measurement time is 16 h, which is 1/2 shorter than that of full spectrum counting.

In arid regions, the tritium concentration in groundwater is typically very low and often falls below the minimum detectable activity (MDA) of the conventional liquid scintillation counter (LSC). Therefore, to measure the tritium activity concentration, it is necessary to lower the detection limit so that the scintillation counter can detect it. In the present study, several methods are discussed which are effective at lowering the detectable activity of tritium. One of these methods is to enrich the tritium activity concentration by ten- to fortyfold of the initial concentration of the tritium. Twelve spiked samples with known amounts of tritium, five with high concentrations and seven with low concentrations, were enriched by the electrolysis process. The results indicated that enriching the tritium levels in groundwater lowers the MDA value. Other methods are minimizing background radiation using low-background materials for sample containers, increasing the measurement efficiency of the scintillation counter and counting time, and shielding the sample from environmental radiation using the shutter option in LSC. Moreover, reducing the number of interfering contaminants in the sample can lower the uncertainty in measuring the tritium concentration in the water sample, which is beneficial for detecting low-level tritium in water to ensure public health and safety.

Tritium levels in the groundwater of arid regions are very low; in most cases, these low tritium levels cannot be detected using a conventional liquid scintillation counter (LSC). To measure the tritium activity concentration, low-level tritium in groundwater needs to be enriched by a known factor so that the scintillation counter can detect it. An electrolysis process with electrolytic cells was designed and fabricated in our laboratory following the International Atomic Energy Agency (IAEA) instructions. Nine spiked samples with a known quantity of tritium were enriched, and the tritium activity concentration was measured using the scintillation counter. The enriched water exhibits a comparable level of spiked samples, albeit with some degree of uncertainty. A correlation was drawn among the tritium activity, enrichment factor, and the required time for the electrolysis procedure. This study confirmed that an enrichment process of approximately ten- to fortyfold of the initial concentration of the tritium could be achieved using the electrolysis process with the fabricated electrolytic cells. The simple design and fabrication of the electrolysis process by controlling various parameters make it affordable to measure low-level tritium using a conventional LSC. Various statistical analyses confirmed the accuracy and precision of the data obtained by the electrolysis process. This enrichment technique would prove valuable in regions where tritium levels in groundwater are extremely low, making them challenging to detect using conventional liquid scintillation counter. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carbon-14 (14C) is a pure beta-emitting radionuclide with a half-life of 5730 ± 30 y. Considering the long half-life and its biological importance, significant attention is given to monitoring 14C in the vicinity of nuclear facilities. The 14C measurement technique employed by the majority of environmental monitoring laboratories for impact assessments in the vicinity of nuclear facilities is based on the thermal oxidization of the samples and the determination of activity by liquid scintillation counting. One of the difficulties faced by these laboratories is the nonavailability of a suitable matrix-matching reference material which is truly representative of the type of sample being analyzed. In this study, an effort has been made to develop a reference material that is representative and has a similar thermal oxidation/combustion property as that of a typical terrestrial plant biota observed in the vicinity of the nuclear power plants of India for quality assurance programs. A prebomb era wood (~150 years old) was identified as a potential secondary reference material. The stable carbon ratio (d13C) of the sample was determined by isotopic ratio mass spectrometer (IRMS), and the mean value was -26.33 ± 0.47 ?. The 14C specific activity of the sample was determined by accelerator mass spectrometry and a mean value of 221.6 ± 0.6 Bq kg-1 C was assigned as the reference value to the prebomb wood. In addition, measurements were performed by thermal oxidation in a tube furnace and by analysis of the 14C activity in a liquid scintillation counter. [ABSTRACT FROM AUTHOR]

Monitoring of tritium concentration in tap water is an essential tool to determine the effective dose received from tap water. Liquid scintillation counting (LSC) is a widely used technique for determining tritium in water. Due to the very low activity of tritium in tap water, its detection requires a high-efficiency LSC with the lowest minimum detectable activity (MDA). Low-level tritium analysis in tap water were performed in two LSC models using conventional distillation techniques. The optimal conditions with the lowest MDAs were applied to determine the tritium concentration in the tap water distributed from two main sources located in the Bangkok metropolitan region: Bang Khen and Maha Sawat water treatment plants (WTPs). Twenty-six tap water samples were collected from petrol stations located around both water treatment plants. The results revealed that the amount of tritium in the tap water around the Bangkhen WTP was between 1.88-2.63 Bq/L with an average of 2.28±0.28 Bq/L, whereas those from the Maha Sawat WTP were between 2.01-2.69 Bq/L with an average of 2.44±0.26 Bq/L, which are far below the World Health Organization’s (WHO) guideline limit (10,000 Bq/L) for drinking water. The annual effective dose (AED) for infants, children and adults obtained from tap water samples around the Bangkhen WTP were 0.010, 0.014, and 0.030 µSv/year, respectively, and those from the Maha Sawat WTP were 0.011, 0.015, and 0.032 µSv/year, respectively, which are far below the WHO’s guideline limit (100 µSv/year).

This work presents a development of a new radiocarbon dating system based on CO2 and liquid scintillation counting. The system is flexible enough to be applied in different fields such as radiocarbon dating (up to about 32 000 years span), environmental radioactive monitoring, and determining the fraction of biological carbon in environmentally-ecologically safe biodegradable and bio-synthetic products, and help accreditation to customaries. The implemented system is developed following the standard method (ASTM D6866-06). It has been calibrated tested and verified for CO2 production, absorption, and counting (using appropriate reference materials for the present-day, fossil, and in between ages). These results are optimistic that the developed system can contribute to the accreditation of ongoing and upcoming environment-friendly productions. [ABSTRACT FROM AUTHOR]

Radon is one of the most natural forms of radiation for human exposure. However, high-accuracy measurement of natural radon in water samples is very challenging due to the background correction, data acquisition, and sampling time. Liquid scintillation counter (LSC) and semiconductor alpha spectroscopy detectors are the most commonly used methods of determining radon concentration in water. The present study utilizes both methods to estimate radon in groundwater collected from various locations in the northeast region of Saudi Arabia. The estimated radon concentrations using Hidex 300SL are compared with a Durridge RAD7 detector to evaluate each apparatus's abilities, advantages, and disadvantages. Both methods show radon concentrations between 0.1 and 3.20 Bq/L with an average of 0.96 Bq/L, with a standard deviation of 0.82 Bq/L. The estimated values are found to be in the safe limit recommended by the USEPA and EAEC and are far below the safe level recommended by UNSCEAR and the WHO. Comparing the estimated radon concentration using the two methods shows that although the two devices have many advantages and disadvantages based on the two different techniques, the experimental results are almost the same with experimental error. [ABSTRACT FROM AUTHOR]

In-house receptors (IHRs) were isolated from non-immunized poultry liver to analyze selected contaminants and residues in targeted food and feed using 14C- and 3H-labeled radiotracers. Matrix (2 g) was homogenized and centrifuged with the resultant pellet used as IHRs. These were characterized for total protein contents (6.1 mg mL−1) and compared with commercial receptors for aflatoxins (0.28 mg tablet−1) and chloramphenicol (0.12 mg tablet−1). Gel electrophoresis of the IHRs showed a mixture of polypeptides—an important attribute for multi-residues analysis—compared with commercial receptors that presented specific protein bands at 65 kDa (chloramphenicol) and 70 kDa (aflatoxins). The inhibition index of IHRs for aflatoxins B1 and B2 in wheat and bovine feed and chloramphenicol in bovine tissue at, above, and below maximum limits or minimum required performance limits, revealed an inverse relationship between radiotracer and analyte concentrations. Saturation with increased radioligand concentration up to 5.5 kBq indicated higher holding potential. However, increasing incubation time to 30 min did not significantly increase analyte-binding. The IHRs performance was comparable to commercial receptors with control point averages of 348, 410, 555, and 307 counts per minute determined for gentamicin, chloramphenicol, oxytetracycline, and aflatoxin M1, respectively in local milk samples. [ABSTRACT FROM AUTHOR]

Monitoring of tritium concentration in tap water is an essential tool to determine the effective dose received from tap water. Liquid scintillation counting (LSC) is a widely used technique for determining tritium in water. Due to the very low activity of tritium in tap water, its detection requires a high-efficiency LSC with the lowest minimum detectable activity (MDA). Low-level tritium analysis in tap water were performed in two LSC models using conventional distillation techniques. The optimal conditions with the lowest MDAs were applied to determine the tritium concentration in the tap water distributed from two main sources located in the Bangkok metropolitan region: Bang Khen and Maha Sawat water treatment plants (WTPs). Twenty-six tap water samples were collected from petrol stations located around both water treatment plants. The results revealed that the amount of tritium in the tap water around the Bangkhen WTP was between 1.88-2.63 Bq/L with an average of 2.28±0.28 Bq/L, whereas those from the Maha Sawat WTP were between 2.01-2.69 Bq/L with an average of 2.44±0.26 Bq/L, which are far below the World Health Organization's (WHO) guideline limit (10,000 Bq/L) for drinking water. The annual effective dose (AED) for infants, children and adults obtained from tap water samples around the Bangkhen WTP were 0.010, 0.014, and 0.030 µSv/year, respectively, and those from the Maha Sawat WTP were 0.011, 0.015, and 0.032 µSv/year, respectively, which are far below the WHO's guideline limit (100 µSv/year). [ABSTRACT FROM AUTHOR]

A novel method for direct measurement of 90Sr in liquid samples was developed by using liquid scintillation counter. Based on the shielding performance analysis and the optimum package investigation, the proposed method provides an excellent shielding for the interferences of α-emitters, low- and intermediate-energy β-emitters. A minimum detection activity of 8.0 ± 0.6 Bq·L−1 for 90Sr was obtained. Due to the effective elimination of the quenching interference and counting interference, the method presented in this work can provide the results of 90Sr analysis within 1 h after receiving the sample. [ABSTRACT FROM AUTHOR]

The analysis of 41Ca in concrete generated from the nuclear facilities decommissioning is critical for ensuring the safe management of radioactive waste. An analytical method for the determination of 41Ca in concrete is described. 41Ca is a neutron-activated long radionuclide, and hence, for accurate analysis, it is necessary to completely extract Ca from the concrete sample where it exists as the predominant element. The decomposition methods employed were the acid leaching, microwave digestion, and alkali fusion. A comparison of the results indicated that the alkali fusion is the most suitable way for the separation of Ca from the concrete sample. Several processes of hydroxide and carbonate precipitation were employed to separate 41Ca from interferences. The method relies on the differences in the solubility of the generated products. The behavior of Ca and the interfering elements such as Fe, Ni, Co, Eu, Ba, and Sr is examined at each separation step. The purified 41Ca was measured by a liquid scintillation counter, and the quench curve and counting efficiency were determined by using a certified reference material of known 41Ca activity. The recoveries in this study ranged from 56 to 68%, and the minimum detectable activity was 50 mBq g−1 with 0.5 g of concrete sample.

Background: Despite its beneficial effects on human life, the nuclear industry has its own risks. Strontium 90 (90Sr) is one of the most dangerous radionuclides produced by the uranium 235 fission, and replaces the bone calcium in the human body, which causes cancer. Ensuring the safety of nuclear facilities to protect employees, people and the environment is among the main goals of nuclear safety. Given close proximity of the Bushehr nuclear power plant to the Persian Gulf and the likelihood of 90Sr leaking into the marine ecosystem, this study aimed to measure this radionuclide in a sample of the bar-tail flathead fish (Platycephalus indicus) found in the Persian Gulf coastline, as people’s main source of food in the region. Materials and Methods: Samples were taken from 10 points around the Persian Gulf coastline. The samples were analyzed using chromatographic extraction by Sr-resin and counted by the Liquid Scintillation Counter. Results: The concentration of strontium 90 measured in the fish samples was 0.252- 0.955 Bq.kg-1. The mean chemical efficiency in this method was 97.34 ± 0.97 percent. Conclusion: The amount of strontium 90 found in these samples was negligible and within the least detectable range. Despite the 10-year activity of Bushehr nuclear power plant, no evidence of contamination with strontium 90 was found. These results will be very useful in assessing the underlying contamination in environmental monitoring programs.

The present study focused on the measurement of 14C levels by using a passive sampling technique. The sampling period is optimized by exposing the 0.5 N NaOH solution to air and measuring the amount of carbon absorbed. The optimum sampling duration for measurement of 14C in the atmospheric CO2 is found as one day. The absorbed CO2 in NaOH solution was recovered by adding barium chloride, and an average recovery yield was found to be 98.67 ± 0.29%. The average specific activity of 14C for samples collected in two locations is 239.04 ± 25.45 Bq/kg C and 242.89 ± 18.22 Bq/kg C. [ABSTRACT FROM AUTHOR]

This work presents a fast and efficient radiochemical method for the determination of strontium-90 in the presence of high concentration of calcium in sea shells. Using this method, 12 samples of sea shells that have been sampled from the Persian Gulf along the border of Bushehr Province are analyzed. The 90Sr activity is determined by the liquid scintillation counter and Sr resin. This method was validated using the reference material International Atomic Energy Agency. The results can be useful in evaluating background contamination in environmental monitoring programs. [ABSTRACT FROM AUTHOR]

The optimization and validation of a procedure for the determination of tritium from gaseous effluents from a nuclear power plant is described. Optimization included performance assessment of silica gel and a molecular sieve as a material for the adsorption of water moisture from air for continuous tritium sampling. In addition, the usability of such a system for monitoring tritium in laboratory air for low-level tritium measurements was assessed. The molecular sieve showed better performance, with an average desorption efficiency of 95% compared to 78% achieved with silica gel. The memory effect was also lower and more reproducible for the molecular sieve, amounting to 7% on average compared to 35% attained for silica gel. Measurement of low-level tritium in air showed the importance of prior checks of intrinsic tritium levels in the molecular sieve as due to that erroneous results could be produced. [ABSTRACT FROM AUTHOR]

Background: Despite its beneficial effects on human life, the nuclear industry has its own risks. Strontium 90 (90Sr) is one of the most dangerous radionuclides produced by the uranium 235 fission, and replaces the bone calcium in the human body, which causes cancer. Ensuring the safety of nuclear facilities to protect employees, people and the environment is among the main goals of nuclear safety. Given close proximity of the Bushehr nuclear power plant to the Persian Gulf and the likelihood of 90Sr leaking into the marine ecosystem, this study aimed to measure this radionuclide in a sample of the bar-tail flathead fish (Platycephalus indicus) found in the Persian Gulf coastline, as people’s main source of food in the region. Materials and Methods: Samples were taken from 10 points around the Persian Gulf coastline. The samples were analyzed using chromatographic extraction by Sr-resin and counted by the Liquid Scintillation Counter. Results: The concentration of strontium 90 measured in the fish samples was 0.252- 0.955 Bq.kg-1. The mean chemical efficiency in this method was 97.34 ± 0.97 percent. Conclusion: The amount of strontium 90 found in these samples was negligible and within the least detectable range. Despite the 10-year activity of Bushehr nuclear power plant, no evidence of contamination with strontium 90 was found. These results will be very useful in assessing the underlying contamination in environmental monitoring programs. [ABSTRACT FROM AUTHOR]

Groundwater wells in Al- Rusaifah in central Jordan were investigated for radon (222Rn) levels during the winter season using a liquid scintillation counter (LSC). 222Rn was detected in eighteen groundwater samples from six different wells. The concentrations of radon varied from 151.9 to 253.1 Bq/L. The upper concentration limit of 222Rn for drinking water is 11 Bq/L based on the Jordanian Standards for Drinking Purposes. This indicates that 222Rn levels in all groundwater samples exceed the permissible threshold. The health impact assessment of 222Rn showed that for all samples, the total populationweighted average annual effective dose was 3.147mSv/y, which is greater than the maximum value of the general annual effective dose from radon of 0.1 mSv/y, according to the WHO and the European Council. [ABSTRACT FROM AUTHOR]

Liquid Scintillation Counting (LSC) is the most commonly used technique for quantification of 14C in the environmental samples. An optimization study was carried out for the analysis of 14C with the direct carbon dioxide absorption method using LSC. The absorption capacity of CO2 in varying amounts of CO2 absorber Carbo-Sorb E to Permafluor scintillation cocktail volumes is found to be 5.33 ± 0.053 mmol/mL of Carbo-Sorb E. The optimum volume ratio of Carbo-Sorb E to Permafluor scintillation cocktail is found to be 1:1 based on the minimum detection activity (MDA) values. The effect of CO2 loading in the optimized absorption mixture shows that with an increasing CO2 amount (up to saturation) there is an increase in tSIE values which is due to an increase of Compton scattering effect in the CO2 loaded samples. The region of interest (ROI) for 14C measurement is found to be 10–96 keV based on the figure of merit values and the efficiency for detecting 14C is 83.45 % in the optimized ROI window. [ABSTRACT FROM AUTHOR]

The Fukushima Daiichi Nuclear Power Plant accident (2011) released large amounts of radioactive substances into the environment and generated highly radioactive debris. Post-accident countermeasures are currently in the phase of fuel debris removal, which requires the analysis of radioactive contaminants in the environment and fuel. The spectra of solely β-emitting nuclides, such as 90Sr, overlap; thus, an effective method for nuclide separation is desired. Since conventional methods for high-dose sample analysis pose substantial exposure risks and generate large amounts of secondary radioactive waste, faster procedures allowing for decreased radiation emission are highly desirable. In this study, we developed a 90Sr2+ quantitation technique based on liquid scintillation counting (LSC)–coupled capillary transient isotachophoresis (ctITP), along with two-point detection and relying on the rapid concentration, separation, and fractionation of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-complexed 90Sr2+ in a single run. The applicability of our method for the analysis of real-world samples was verified by conducting addition-recovery experiments using a seawater reference material and radioactive liquid waste obtained from the radioactive waste treatment facility at the Japan Atomic Energy Agency. The recovery determined by LSC was 95–113%, indicating successful quantitative analysis. 90Sr recovery was determined to be 90.1% from a contaminated water sample obtained from the Fukushima Daiichi Nuclear Power Plant, which was analyzed using the standard addition of 90Sr. The sensitivity (detection limit = 0.016 Bq) of the proposed method on a radioactivity basis was equal to or higher than that of the conventional method using ion exchange-LSC (0.012–0.07 Bq). Our method allows for the handling of high-dose radioactive samples at the microliter level and is substantially faster than conventional ion exchange protocols, whereas ctITP has not been used for practical applications due to inaccurate collection and lack of a suitable chemical system. The concentration–separation–fractionation protocol in ctITP is successful due to the existence of a rare inert Sr2+ complex and precise fractionation. This study establishes a pathway toward safer and more practical analysis of radionuclides. [Display omitted] • 90Sr quantitation method requiring microliter-scale samples is developed & validated. • 90Sr concentration, separation, & fractionation by CE/LSC are achieved in one run. • Sr ion strongly complexes with UV-active probe (DOTA) to facilitate detection. • High analytical performance is due to the kinetic inertness of the Sr-DOTA complex. [ABSTRACT FROM AUTHOR]

A definitive assessment on the distribution and forming of tritium in RAFM steels which would be considered as the primary candidate structural material for fusion reactor is a key safety requirement for selecting effective decommissioning process of nuclear facilities. In this study, the acid etching is used to determine tritium concentration and distribution of CLAM steel and CLF-1 steel exposure to the mixed gas of 90% deuterium and 10% tritium (1.2 MPa mixed gas, 18 h at 896 K) and later aging for 4 years. The bulk distribution of tritium concentration in both steels is calculated, based on the diffusion equation and finite difference method. In addition, the samples are soaked in distilled water to evaluate the tritium-hydrogen exchange before etching. The results show that the tritium on the metal surface could be effectively removed. There are two forms of tritium distributed in both steels: "soluble tritium" and "non-soluble tritium". And the former is usually less than the latter. Compared with CLAM steel, tritium content in CLF-1 steel is higher. [ABSTRACT FROM AUTHOR]

In this work, a comparative study of two popular radiochemical procedures for 90Sr determination in biological and sediment samples via Cerenkov counting was performed. Comparative tests were carried out with a Liquid Scintillation Counter (LSC) and several key factors related to green analytical chemistry were considered. Chemical yields, time of analysis, cost per sample, hazardous reagents used (H-factor), wastes generated (E-factor) and energy consumed (Q-factor) were calculated. The separation methods are based on two contrasted extraction mechanisms: chromatographic extraction (using Sr resin, a crown-ether diluted in octanol) and liquid-liquid solvent extraction (using HDEHP, an organophosphorus compound), where the chromatographic extraction method was optimized. The developed analytical procedure based on HDEHP was cheaper and faster than the analytical procedure based on Sr resin, according to the green chemistry. On the other hand, the Sr resin method provided a minimum detectable activity (MDA) of 1.1 Bq kg−1, lower than 1.5 Bq kg−1 corresponding to HDEHP method, due to the higher capacity of sample that can be loaded into the resin. The accuracy and reproducibility of both methods was confirmed in the analysis of certified reference materials provided by the International Atomic Energy Agency (IAEA). [ABSTRACT FROM AUTHOR]

The liquid scintillation counting procedure for tritium quantification in environmental samples was optimized with respect to sample to cocktail volume ratio, fixing of region of interest of tritium spectra, and choice of counting vials for measurement of low-level activities of tritium in water samples. The optimum sample to cocktail ratio for Aqua-light scintillation cocktail based on the MDA values was found to be 8: 12 mL. The optimum window for tritium at optimum sample to cocktail ratio was found to be 2–12 keV based on figure of merit values, and the reduction in the background count rate was 31% compared to full window. The efficiency of the system at optimum sample to cocktail ratio was studied using two different quenching agents, carbon tetrachloride (CCl4) and nitromethane at different quench levels. It was found that quench effects were stronger for the standards with nitromethane compared to CCl4 at any specific volume. The tritium recovery factor for distillation technique, which is used for removing quenching agents present in water samples, was found to be 95% with the relative standard deviation of 0.34%. The conditions established in this paper are useful for measurement of low-level activities of tritium in the environmental samples. [ABSTRACT FROM AUTHOR]

Radon is known as the main source of radiation for the general public. Results of extensive measurements of radon in water samples collected from private wells, natural springs and public water supply in Croatia are presented and annual effective doses are estimated. Measurements were performed by two different methods: the emanometry method (by using the AlphaGUARD instrument with additional AquaKIT module) and/or the liquid scintillation method (by using LSC TriCarb 2900). Water samples were collected in public water supplies in urban areas as well as private wells and springs in rural areas. The obtained average radon activity concentration based on the extensive measurement of almost 1000 water samples is 4.1 ± 1.9 Bq/l, with a minimum value of 0.2 and maximum value of 36 Bq/l respectively. The wide range of measured values is a consequence of the source of the water sample (ground/natural water versus treated water) as well as the geological structures around the water source. All estimated ingestion doses due to radon assuming consumption of 2 l of water per day from the observed source were within the interval 6.3–36.8 μSv (with calculated average and standard deviation 19.3 ± 10.3 μSv) for the water consumption from private wells and natural springs and 2.4–40.0 μSv (with calculated average and standard deviation 13.0 ± 10.5 μSv) for the water consumption from the public water supplies. • Measurements of radon in drinking water in Croatia were performed. • Radon concentrations in public water supplies are below reference level. • The influence of local geology on radon in wells and natural springs is observed. • Water samples collected from wells and natural springs follow lognormal distribution. • The doses from ingestion and inhalation of radon from drinking water are estimated. [ABSTRACT FROM AUTHOR]

The two kinds of liquid scintillation counters (LSCs) from PerkinElmer, Quantulus GCT 6220 and Quantulus 1220, have been compared on their basic performances, i.e., background count rate, counting efficiency, α/β discrimination, and instrument stability, by determining the radioactivity of the radionuclides of H, C, Am, Sr/Y, Co, and Cs. Except for the highlight of Quantulus GCT 6220 in stability and that of Quantulus 1220 in background for α counting, the two kinds of LSCs are comparable in the basic performances to each other. [ABSTRACT FROM AUTHOR]

The present study was carried out to survey the levels of plutonium isotopes ( 238 , 239 , 240 Pu) and strontium ( 90 Sr) in domestic seafood in Korea. In current, regulatory authorities have analyzed radionuclides, such as 134 Cs, 137 Cs and 131 I, in domestic and imported food. However, people are concerned about contamination of other radionuclides, such as plutonium and strontium, in food. Furthermore, people who live in Korea have much concern about safety of seafood. Accordingly, in this study, we have investigated the activity concentrations of plutonium and strontium in seafood. For the analysis of plutonium isotopes and strontium, a rapid and reliable method developed from previous study was used. Applicability of the test method was verified by examining recovery, minimum detectable activity (MDA), analytical time, etc. Total 40 seafood samples were analyzed in 2014–2015. As a result, plutonium isotopes ( 238 , 239 , 240 Pu) and strontium ( 90 Sr) were not detected or below detection limits in seafood. The detection limits of plutonium isotopes and strontium-90 were 0.01 and 1 Bq/kg, respectively. [ABSTRACT FROM AUTHOR]

A simple analytical method was developed for the determination of Sr in fish bone ash samples. The adsorption behaviors of 26 metal ions on Sr Resin and AnaLig Sr-01 resin were examined. The obtained distribution coefficients show that Sr Resin has suitable selectivity. The proposed method consists of co-precipitation with calcium phosphate and purification by Sr Resin. After ingrowth, Y was measured using a liquid scintillation counter. The proposed method was validated by radiometric analysis of Sr in certified reference materials. Finally, the proposed method was applied for interlaboratory comparison. The analytical results by proposed method showed acceptable z scores. [ABSTRACT FROM AUTHOR]

In the framework of a National Environmental Radiation Survey Program, a total of 950 samples were collected and analyzed over 7 years. The program covers different compartment of Lebanese environment, rivers, wells, marine samples, soil, and foodstuff. Air was monitored continuously through a radiation early warning network system. Data collected from 2009 to 2015 are presented in this work. Gross alpha/gross beta values in well samples were below the guidance levels stated by the WHO. Cesium-137 was detected in milk samples, whey, and jam. However, its content was much lower than the national permissible level, while its activity concentration in marine samples was lower than the values reported in studies carried out in the Mediterranean Sea. The activity concentration of K in food samples was comparable to studies carried out in neighboring countries and higher than the content determined in non Mediterranean countries. Concerning marine environment, the activity concentrations of natural radionuclides U, Th, and K were comparable to those reported in other studies carried out in different countries. As well as their content in rivers and sediments was lower than those reported in neighboring region. Potassium-40 in food and Po in fish were the main contributors to the internal dose. The average annual effective dose due to external exposure and internal, excluding radon gas which constitutes around 43 % of the total dose, was found to be lower than the total worldwide value, 2.4 mSv year. Iodine-131 was detected in grass samples, collected in 2011 during Fukushima accident; its content ranged from 0.40 ± 0.06 to 0.9 ± 0.1 Bq kg, as well as Cs was detected in some seafood samples imported from Japan and neighboring countries. Its activity concentration varied between 0.15 ± 0.04 and 0.40 ± 0.02 Bq kg. [ABSTRACT FROM AUTHOR]

An analytical procedure for detecting 226 Ra in naturally occurring radioactive materials (NORMs) using a liquid scintillation counter (LSC) was developed and validated with reference materials (zircon matrix, bauxite matrix, coal fly ash, and phosphogypsum) that represent typical NORMs. The 226 Ra was released from samples by a fusion method and was separated using sulfate-coprecipitation. Next, a 222 Rn-emanation technique was applied for the determination of 226 Ra. The counting efficiency was 238 ± 8% with glass vials. The recovery for the reference materials was 80 ± 11%. The linearity of the method was tested with different masses of zircon matrix reference materials. Using 15 types of real NORMs, including raw materials and by-products, this LSC method was compared with γ-spectrometry, which had already been validated for 226 Ra analysis. The correlation coefficient for the results from the LSC method and γ-spectrometry was 0.993 ± 0.058. [ABSTRACT FROM AUTHOR]

A new tritiated water measurement method with plastic scintillator pellets (PS-pellets) by using a conventional liquid scintillation counter was developed. The PS-pellets used were 3 mm in both diameter and length. A low potassium glass vial was filled full with the pellets, and tritiated water was applied to the vial from 5 to 100 μl. Then, the sample solution was scattered in the interstices of the pellets in a vial. This method needs no liquid scintillator, so no liquid organic waste fluid is generated. The counting efficiency with the pellets was approximately 48 % when a 5 μl solution was used, which was higher than that of conventional measurement using liquid scintillator. The relationship between count rate and activity showed good linearity. The pellets were able to be used repeatedly, so few solid wastes are generated with this method. The PS-pellets are useful for tritiated water measurement; however, it is necessary to develop a new device which can be applied to a larger volume and measure low level concentration like an environmental application. [ABSTRACT FROM AUTHOR]

Liquid scintillation counting (LSC) supports a range of environmental science measurements. At Pacific Northwest National Laboratory, we are constructing an LSC system with an expected background reduction of 10-100 relative to values reported in the literature. In this paper, a number of current measurement applications of LSC have been considered with an emphasis on determining which aspects of such measurements would gain the greatest benefit: improved minimum detectable activity (MDA), reduction in sample size, and reduction in total analysis time. [ABSTRACT FROM AUTHOR]

A novel method for determination of 210 Pb activity concentration using a liquid scintillation counter (LSC) in environmental samples is presented. After radiochemical separation of 210 Pb on Eichrom Sr Resin column, the decay product 210 Bi starts to in-grow and interfere with the 210 Pb during measurement with LSC. Instead of eliminating this interference, a novel method utilises 210 Bi in-growth to improve the detection efficiency and subsequently to lower the minimum detectable activity ( MDA ). This allows for substantial reduction of the MDA compared to conventional methods. [ABSTRACT FROM AUTHOR]