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Because radioactive 177Lu has a wide range of possible applications in radiopharmaceuticals, its removal from medical wastewater is particularly important. Montmorillonite clay was employed as an adsorbent in this study. Radioactive solutions were prepared with dilutions of the solution containing 177Lu at various concentrations, in which it was present as Lu3+. ULEGe detector in gamma spectrometer was used to measure 177Lu gamma rays emitted from the radioactive aqueous solutions. The results obtained showed that it is possible to remove 177Lu with a high yield of approximately 90% and it is effective in a period of 90 min under acidic conditions. From the findings, it can be argued that Montmorillonite clay, as an abundant and sustainable adsorbent, may also be suitable for the disposal of different radioactive medical wastes such as 131I and 99mTc, and also the technique based on gamma ray spectroscopy can be used for fast and practical measurements of radioactive material amounts.

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This comprehensive study examines the concentration of natural radionuclides in bricks from the Terai region of the Koshi province, aiming to assess the radioactivity levels and associated radiological hazards, ultimately quantifying the dose limit. The average concentrations of 226Ra, 232Th, and 40K were 27.1 ± 5.7, 42.6 ± 9.8, and 601.5 ± 93.8 Bq/kg, with their respective contributions to total activity being 20.18 %, 45.35 %, 34.48 %,. Despite this, their concentration distribution followed the pattern 40K > 232Th > 226Ra. The elevated presence of 40K in the bricks is attributed to the use of phosphate fertilizers in the soil to enhance crop productivity. Notably, the calculated values of radiological hazard parameters, including radium equivalent activity, absorbed gamma dose, and effective dose, are well below the recommended safety thresholds. Consequently, this study suggests that bricks, when used in substantial quantities, pose no significant radiological risks and are considered safe for use as a building material. The extension of such investigations nationwide is recommended to assess the overall radioactivity levels and establish dose limits.

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

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This work is devoted to comparing the Monte Carlo simulation tools: Monte Carlo Calculation-Multi Track (MCC-MT) software and EffMaker software, in terms of the efficiency when using them in field applications for measurement of radioactive waste or their free release from control. The detection efficiency of volumetric gamma sources' reference samples in the form of a metal cylinder, a rod, and a rod placed in a 200-L barrel with sand, in the energy range of 50-1500 keV, has been simulated. Comparison of simulation results with in-situ measurements by a mobile HPGe spectrometer showed that the discrepancy between calculation and experiment for all measurement geometries is larger for EffMaker, which is associated with a less accurate detector model than in MCC-MT. Both programs give acceptable results in terms of accuracy and are recommended for calibrating gamma spectrometers in the case of field measurements.

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Objective:To simulate the effects of different thyroid-neck phantoms and monitoring positions on the detection efficiency of portable γ spectrometer, and to provide guidance for more accurate on-site measurement of 131I activity in the human thyroid. Methods:Based on the models of 4 typical thyroid-neck phantoms and a 3-inch NaI (TI) γ spectrometer used for the measurement of 131I in the thyroid and combined with the possible field monitoring scenarios, the Monte Carlo method was used to simulate and calculate the detection efficiency of the spectrometer under different conditions of monitoring distance, thyroid depth and thyroid volume. Results:The detection efficiency decreased significantly with the increase in the distance between the detector and the neck surface. The efficiency close to the neck surface was about 15 times that at 15 cm away from the neck surface. The detection efficiency decreased significantly with the increase in thyroid depth. When it was measured at the surface of the neck, the detection efficiency of thyroid at depth of 2 mm was about 3.6 times that of 30 mm. The detection efficiency decreases with the increase in thyroid volume. When it was measured at the neck surface, the detection efficiency of thyroid with 1 ml volume was 1.71 times that with 30 ml. The detection efficiency decreased with the center-point offset of the detector, especially at the neck surface, an offset of 2 cm would reduce the detection efficiency by about 15%.Conclusions:Not only the measurement distance used in calibration, but also the information of the depth and volume of thyroid in the neck-thyroid phantom, is important to know in advance for an accurate measurement of 131I activity in thyroid by using a portable gamma spectrometer.

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@#<b>Objective</b> To measure the specificactivity of natural and synthetic radionuclides in the environmental soil of Panjin, China and determine the content of radionuclides in the surface soil, and to conduct a scientific assessment of the radiation health risks of residents in this area. <b>Methods</b> Thirty-one surface soil samples were collected within the jurisdiction of Panjin, and a high-purity germanium detector was used for γ spectrum analysis to obtain the content of radionuclides and the current environmental radioactivity level. The two independent samples mean <i>t</i>-test was used to compare the specific activity data of radionuclides in soil samples between Panjin and Liaoning Province or China. <b>Results</b> The meanspecific activities of natural radionuclides ²³⁸U, ²²⁶Ra, ²³²Th, ⁴⁰K, and synthetic radionuclide ¹³⁷Cs in the surface soil samples of Panjin were 18.7 Bq/kg, 19.6 Bq/kg, 23.5 Bq/kg, 604.6 Bq/kg, and 0.9 Bq/kg, respectively. <b>Conclusion</b> The specific activities of natural and synthetic radionuclides in the surface soil samples of Panjin Area at the background level, causing a very low health risk to the people in this area.

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A standard procedure for characterizing the high-purity germanium detector (HPGe), manufactured by Canberra Industries Inc., is performed directly by the company using patented methods. However, the procedure is usually expensive and must be repeated because the characteristics of the HPGe crystal changes over time. In this work, the principles of a technique for use in obtaining and optimizing the detector characteristics based on a cost-effective procedure in a standard research laboratory were developed. The technique required the geometrical parameters of the detector to be determined as precisely as possible by the Monte Carlo method in parallel with the optimization process based on evolutionary algorithms. The development of this approach facilitated the modeling of the HPGe detector as a standardized procedure. The results would be also beneficial in the development of gamma spectrometers and/or their calibrations before routine measurements.

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We demonstrate the capability of Regularized Particle Filter (RPF) based algorithm to localise and quantify an orphan gamma-ray source situated in an unknown area using a single radiation detection system. The radiological measurements are made in the form of gamma spectra at multiple locations using an in-house developed backpack gamma spectrometer based on a 2″ x 2″ NaI(Tl) scintillation detector. We developed an Android application based on RPF which processes the gamma spectra received from the backpack over Bluetooth along with location information acquired from the smart phone's GPS in real time to show the source location in latitude, longitude format and source strength. To examine the performance of the algorithm, the radiological source search operation is carried out with 5.74 GBq 137Cs and 2.66 GBq 60Co in two independent experiments. The sources are located within an error of 10 m in location and 10% in source strength during the multiple experiments. The experiments are conducted in an open field where the attenuating medium for gamma rays would appear homogeneous at all the measurement points. Further improvements in the methodology are required for the localisation and quantification of source in an urban environment with a single detector.

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Objective Based on the lanthanum bromide scintillator detector, the calculation method of G(E) function was developed to measure the air absorbed dose rate. Methods Firstly, the gamma energy spectrumof the lanthanum bromide detector were simulated and the response functions with different energies were determined with Monte Carlo simulation method. Then, the G(E) function was calculated by the least square method. Finally, the air absorbed dose rate measured by the lanthanum bromide detector using G(E) function conversion method was compared with the theoretical calculation value based on the point source experiments. Results The experimental verification results showed that the relative deviation between thecalculated value with G(E) function and the theoretical calculation value wasmostly controlled within ± 6%, which verified the accuracy of G(E) function. Conclusion The results showed that the method of G(E) function could be applied to calculate the gamma radiation dose rate based on the in-situ the gamma spectrum with LaBr3 detector.

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To improve the capability of underwater gamma spectrometer to quantify radiation levels slightly above the background radiation in the seawater, the minimum detection activity (MDA) and factors including the background count, detection efficiency and acquisition time were studied using Monte Carlo simulation and field experiments. The simulation results show that the crystal type selected in the spectrometer and its volume, enclosure materials of the spectrometer and its thickness all affect the marine detection efficiency in in-situ measurement, and thus determine MDA of the underwater gamma spectrometer. The acquisition time and the placement depth of the spectrometer in the seawater also affect the MDA in the in-situ measurement. Some research data and suggestions on design and use of underwater gamma spectrometer were presented, which are of guiding significance for the in-situ radioactivity measurement in the marine environment.

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In the case of a radiological incident, large numbers of affected people should get rapid internal contamination screening, so a portable internal contamination monitor for large-scale application has been developed. It comprises dual detectors, a digital gamma spectrometer, and analysis software. Experiments carried out with a Chinese adult man model. Because of the inadequate shielding and poor detector resolution, the monitor is not sensitive to the lower energy emitters. However, it shows the excellent performance for the emitters above 661 keV. MDA for Cs-137, Y-88, and Co-60 reached 320Bq, 300Bq, and 530Bq in 5-min measurement. Due to the strong mobility, considerable detection limit, and low cost, the monitor can be applied to the rapid internal contamination screening in a radiological incident.

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Objective To investigate the contents of radionuclide 137 Cs in seafood from coastal areas of Zhejiang province, and to estimate the annual committed effective dose to population in different regions from ingestion of 137 Cs in seafood. Methods Three representative monitoring areas were set on the coastaline of Zhejiang province, and the locally popular seafoods were selected as monitoring objectives. The contents of radionuclide 137 Cs were detected using HPGeγspectrometry. The committed effective doses were estimated based on monitoring results and consumption data on seafoods in Zhejiang. Results The detection ratio of 137 Cs in seafood produced on coastal areas of Zhejiang province was estimated to be 35.3％ ( 36/102 ) . Specific activity detected ranged from 0. 004 to 0. 140 Bq/( kg, Wet ) . Committed effective doses from ingestion of 137 Cs in one year to the population in island region, coastal region and inland region were 3. 03 × 10-5 , 1. 63 × 10-5 , 3. 38 × 10-6 mSv, respectively, far lower than the world committed effective dose resulting from internal exposure. Conclusions At present, the content level of 137 Cs in seafood produced on the coastal areas of Zhejiang province is much lower than the national standard limit, and the dose burden to the population is very minor with no health impact to the population.

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Objective@#To investigate the contents of radionuclide 137Cs in seafood from coastal areas of Zhejiang province, and to estimate the annual committed effective dose to population in different regions from ingestion of 137Cs in seafood.@*Methods@#Three representative monitoring areas were set on the coastaline of Zhejiang province, and the locally popular seafoods were selected as monitoring objectives. The contents of radionuclide 137Cs were detected using HPGe γ spectrometry. The committed effective doses were estimated based on monitoring results and consumption data on seafoods in Zhejiang.@*Results@#The detection ratio of 137Cs in seafood produced on coastal areas of Zhejiang province was estimated to be 35.3% (36/102). Specific activity detected ranged from 0.004 to 0.140 Bq/(kg, Wet). Committed effective doses from ingestion of 137Cs in one year to the population in island region, coastal region and inland region were 3.03×10-5, 1.63×10-5, 3.38×10-6 mSv, respectively, far lower than the world committed effective dose resulting from internal exposure.@*Conclusions@#At present, the content level of 137Cs in seafood produced on the coastal areas of Zhejiang province is much lower than the national standard limit, and the dose burden to the population is very minor with no health impact to the population.

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A gamma spectrometric method is presented for in situ radiation monitoring of bottom sediments with contaminated layer of unknown thickness to be determined. The method, based on the processing of experimental spectra using the results of their simulation by the Monte Carlo method, is proposed and tested in practice. A model for the transport of gamma radiation from deposited radionuclides 137Cs and 134Cs to a scintillation detection unit located on the upper surface of the contaminated layer of sediments is considered. The relationship between the effective radius of the contaminated site and the thickness of the layer has been studied. The thickness of the contaminated layer is determined by special analysis of experimental and thickness-dependent simulated spectra. The technique and algorithm developed are verified as a result of full-scale studies performed with the submersible gamma-spectrometer.

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Now-a-days several standard and well calibrated radioactive sources are available for gamma spectrometer efficiency calibration but at some situations, like lack of standard calibrators, in need of verification of standards or preparation a standard with the same properties with the interested sample, 40K is a cheap and easily available radioisotope that could be used. In this study, eighteen different inorganic potassium compounds that have different potassium abundances, types of elements, densities and particle sizes were studied as efficiency verification sources. Gamma spectrometric measurements were performed and it was dawn on the compounds which have low density, low molecular weight and high potassium abundance showed higher 40K activity concentration. It was also indicated that potassium abundance of the compound was the dominant property in these parameters. The activity concentrations were also calculated theoretically and results were in good agreement with the experimental results. Thus it was reported that the 40K compounds with these properties are much suitable for to use as verifying sources or gamma calibrators.

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In this article, a GEANT4 Monte Carlo simulation toolkit was used to study the response of the cosmic-ray induced background on a High-Purity Germanium (HPGe) gamma spectrometer in the wide energy range, up to 100MeV. The natural radiation background measurements of the spectrometer were carried out in the energy region from 0.04 to 50MeV. The simulated cosmic-ray induced background of the Ge detector was evaluated in comparison with the measured data. The contribution of various cosmic-ray components including muons, neutrons, protons, electrons, positrons and photons was investigated. We also analyzed secondary particle showers induced by the muonic component.

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In this paper, three different widely-used measurement techniques for environmental gamma dose rate were studied and compared, i.e., the thermoluminescent dosimeter, the portable survey meter and the spectrometric analysis. Thirteen investigation sites were selected, and the TLDs were arranged to accumulate the radiation signals during an interval of about one quarter, the instant dose rates by using a portable survey meter were collected around the site, and top surface soils were sampled in the surroundings for radionuclides analyzing in laboratory. The results from these methods were compared, which revealed high correlations. The differences and possible uncertainties for the three methods were analyzed, inspired a further study should be conducted to have more successful estimation of dose rate in surface air.

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This work studies the activity concentration of natural radioactivity in 20 different types of rice, including imported rice and that produced locally. The rice samples were collected from markets and farms in Iraq, and then a natural radioactivity investigation was done in the environmental laboratory of the Kufa University, using gamma-ray spectrometer systems. The research focused on measuring the activity concentration of natural radioactivity (238U, 232Th, and 40K) to determine the level of the radium equivalent activity, internal hazard indices, and annual effective dose. The results show that all these parameters are within the permissible limits and that radioactivity is present in almost all foodstuffs at levels ranging from 40 to 600 Bq/kg of food. Radioactivity in foodstuffs is attributed to a natural source, potassium-40, and to artificial sources, which include industrial radioactivity, weapons testing, and accidents involving radioactivity. In this article, radionuclides have been identified for most of the common species of rice available in Iraqi markets; in addition, radium equivalent activity, internal hazard indices, and annual effective dose were calculated and compared with the permissible dose to estimate the risk of radioactive isotopes in the rice crop.

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The determination of (137)Cs inventory is widely used to estimate the soil erosion or deposition rate. The generally used method to determine the activity of volumetric samples is the relative measurement method, which employs a calibration standard sample with accurately known activity. This method has great advantages in accuracy and operation only when there is a small difference in elemental composition, sample density and geometry between measuring samples and the calibration standard. Otherwise it needs additional efficiency corrections in the calculating process. The Monte Carlo simulations can handle these correction problems easily with lower financial cost and higher accuracy. This work presents a detailed description to the simulation and calibration procedure for a conventionally used commercial P-type coaxial HPGe detector with cylindrical sample geometry. The effects of sample elemental composition, density and geometry were discussed in detail and calculated in terms of efficiency correction factors. The effect of sample placement was also analyzed, the results indicate that the radioactive nuclides and sample density are not absolutely uniform distributed along the axial direction. At last, a unified binary quadratic functional relationship of efficiency correction factors as a function of sample density and height was obtained by the least square fitting method. This function covers the sample density and height range of 0.8-1.8 g/cm(3) and 3.0-7.25 cm, respectively. The efficiency correction factors calculated by the fitted function are in good agreement with those obtained by the GEANT4 simulations with the determination coefficient value greater than 0.9999. The results obtained in this paper make the above-mentioned relative measurements more accurate and efficient in the routine radioactive analysis of environmental cylindrical soil samples.

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Objective To explore the effeetiviness of the method of LabSOCS(Laboratory sourceless calibration software)efficiency calibration in laboratory rapid analysis for emergency monitoring of nuclear incidents.Methods The detection efficiency of three kinds of environmental samples in emergency monitoring Wag calculated bY using the LabSOCS efficiency calibration method,and compared with the values that were obtained by way of radioactive source calibration method.Results The maximum relative deviation of the detection efficiency between the two methods was less than 15%,and the values with relative deviation less than 5%accounted for 70%.Conclusions The LabSOCS efficiency calibration method might take the place of radioactive source efficiency calibration method,and meet the requirement of rapid analysis in emergency monitoring of the nuclear incidents.