Analytical Studies on the Radionuclide Levels of Sediment and Water in an Agricultural Environment in the Egyptian Delta

This paper is an environmental investigation of the concentration values of radioisotopes and hazardous elements, aimed to shed light on industrial pollution and the effect of using fertilizers in the period of irrigation water drainage from cultivated lands, especially in the River Nile, irrigated, and draining channels in the middle portion of the Egyptian river delta. Different samples were analyzed, both for water and sediment. Many physical and chemical characteristics of samples were investigated. Among them are the quantitative measure of the acidity or basicity of aqueous or other liquid solutions (pH), grain size, and the total organic matter content (TOM) have been determined for sediments. pH and TDS, beside other types of pollutants, were determined for water samples. The water and sediment samples pH are slightly alkaline. The mean value of TDS for water samples is 488 mg/l, while he usual TDS value in river is 500 mg/l. The TOM values show that the sediment samples are poor in organic matter content. The bicarbonate range in the water samples is smaller than the same range in river water. The levels of Ra-226, Th-232, and K-40 activity in sediments are highly correlated. Natural radionuclides seem to correlate with the artificial Cs-137 in sediment. For this peruse, a 240 cm3 high-purity germanium reagent Type-B was used to quantify the levels in each sample with a relative accuracy of 50 %. The radioactive element K-40 is having a typical value of 12.5 Bq/kg. The concentrations of both Cu beside Zn in water samples is smaller if compared with values that quoted by the WHO, the US-EPA, and the EC. It was also found that the average levels for both Cd and Mn are found to be close to the internationally recommended levels. The water and sediments in the southern part of the canal contain higher concentrations of heavy metals and radioactive isotopes than in the rest of the canal

Dose Evaluation of Head and Neck Cancer IMRT Treatment Planning Based on Gamma Index Analysis of Varian Halcyon 2.0 Linac

Varian Halcyon 2.0 linear accelerator was launched and became available for clinical use in 2018. Therefore, it is necessary to evaluate the accuracy of exit fluence of the Halcyon 2.0 for quality assurance (QA) of head and neck cancer treatment planning, pretreatment, and treatment. The accuracy of the exit fluence for twenty treatment plannings has been evaluated by conducting gamma analysis for QA pretreatment and treatment in each field and composite field by using criteria for gamma index 3 %/3 mm and 2 %/2 mm. The QA pretreatment results are in the average value for each criterion for each field and composite fields on actual gantry angle and null gantry angle with gamma passing rate (GPR) of over 99 % (range 99.78 %-99.95 %) The total treatments consisted of 2717 fractions. The analysis results of GPR for fields were 99.32 % and 97.74 % for gamma indexes of 3 %/3 mm and 2 %/2 mm, respectively. In addition, the analysis results of GPR for composites were 95.46 % and 81.38 % for gamma indexes of 3 %/3 mm and 2 %/2 mm, respectively. Based on this result, the average GPRs of QA pretreatment are ≈ 99 % of the total pixels. This means the prediction dose of Varian Halcyon 2.0 is accurate. The average GPRs of treatment is nearly  90 %, showing that Varian Halcyon 2.0 is effective for creating treatment plans for complex cases

Assessment of Health Risk of Exposure to Alpha-Emitters in Cheese Samples Collected from Iraqi Markets

In this research, alpha-emitter concentrations of 222Rn, 226Ra, and 238U in Iranian, Turkish, Egyptian, Saudi Arabian, and Iraqi canned cheeses that are available in Iraqi markets were measured using the CR-39 detector. Also, the health risk parameters associated with the ingestion of alpha-emitter radionuclides, such as the annual average internal effective dose (AAIED) and the risk of an excess cancer fatality per million persons (RECFPMP), were calculated. The results show that the average values of 222Rn, 226Ra, and 228U concentrations for all samples in the present study were 3.7±0.38 Bq/m3, 25.24±2.63 mBq/kg, and 0.025±0.002 ppm, respectively. The average values of AAIED and RECFPMP were 0.175±0.018 µSv/y and 0.674±0.070, respectively. The results show that the highest value of alpha-emitters as well as health risk parameters were found in cheese samples produced in Saudi Arabia, while the lowest results were found in Egyptian samples. They were, nevertheless, less than the permissible value and the risk value. According to the current study, the consumption of those cheese products poses no health risks

Comparative Analysis of Turbulence Models for Thermal-Hydraulic Simulations in Aqueous Homogeneous Reactors

This article presents a comparative study of various turbulence models applied in the context of thermal-hydraulic simulations for liquid fuel reactors, specifically Aqueous Homogeneous Reactors (AHR) using Computational Fluid Dynamics. The objective was to assess the suitability of the turbulence models by comparing their results with data obtained from Large Eddy Simulation (LES). For that purpose, was compared the flow behavior predicted using the k-ε, SST, GEKO, DES, SBES, and LES turbulence models. The calculations were carried out in a simplified computational model derived from a pre-existing three-dimensional AHR conceptual design. By utilizing this simplified model, the study aimed to focus on the computational differences between the turbulence models, while minimizing the influence of other factors. The calculation results revealed that the k-ε model exhibited significant discrepancies with the LES, with relative differences for the fuel solution maximum temperature reaching up to 75 %. Among the remaining RANS models, the Shear Stress Transport (SST) model demonstrated the best compromise between accuracy and computational efficiency, with differences below 5 % and requiring only 1/5th of the time, compared to the LES model.  The Scale-Resolving Simulation (SRS) models,DES and SBES, provided a more comprehensive description of flow behavior and results closer to LES, albeit with higher computational demands. Between these two models, only the DES model exhibited relative differences below or equal to     1 % compared to the LES model for the studied thermohydraulic parameters

Neutronic Parameter Analysis of Plate-Type Fueled TRIGA 2000 Reactor by MCNPX

A novel simulation to calculate the neutronic parameters of the TRIGA 2000 reactor using plate-type fuel has been performed. The plate fuel used was produced by the Indonesian Nuclear Industry (PT INUKI) with U3Si2-Al material. Neutronic parameters based on INUKI’s plate-type fuel dimension and the current TRIGA’s configuration were simulated using MCNPX. The simulation was performed by modeling the complete reactor’s configuration on a fresh fuel core state. We obtained the kinetic parameter values from the simulation, i.e., delayed neutron fraction of 8.11×10‑3, a prompt neutron lifetime of 2.0551×10‑4 s, and an average neutron generation time of 1.87×10‑4 s. The excess reactivity of the reactor was 9.02 %Δk/k, while reactivity in the one-stuck-rod state was below ‑0.5 $with an average value of ‑3.40$). The average thermal neutron flux peak occurred at the central irradiation position with the value of 3.0×1013 to 3.1×1013 n/(cm2 s). The reactor has a power peaking factor of 1.379 in the control rod position of 0 % on D3 fuel. The reactor had a negative feedback reactivity coefficient, except for the moderator coefficient. These results suggest that the current configuration of plate-type fuel met the nuclear reactor neutronic safety standards

The Quantitative Effect of Noise and Object Diameter on Low-Contrast Detectability of AAPM CT Performance Phantom Images

Parameters for determining computed tomography (CT) image quality include noise and low-contrast detectability. Studies on low-contrast detectability using the AAPM CT performance phantom have several limitations, such as the absence of quantitative information on the effect of noise and object size on low-contrast detectability. In this study, the quantitative effect of noise and object diameter on low-contrast detectability were investigated. Images of the American Association of Physicists in Medicine (AAPM) CT performance phantom model 610 were acquired with a tube voltage of 120 kV and tube currents of 50, 100, 150, and 200 mA. The low-contrast section of the AAPM CT performance phantom model 610 has objects with diameters between 2.5 and 7.5 mm. We analysed the mean CT number, noise level, signal-to noise ratio (SNR), and contrast-to-noise ratio (CNR), acquired using MatLab software. The results obtained indicate that noise and object size affect low-contrast detectability. The CNRs increase linearly with increasing of object diameter with R2 of 0.88, 0.67, 0.75, and 0.83 for tube currents of 50, 100, 150 and 200 mA, respectively

Dose Response of Personnel OSL Dosimeter to the Cesium-137 and 80 kVp X-ray Exposure

Over the years, several types of dosimeters have been introduced for accurate dose assessment. The OSL dosimeter is one of them. It is used to monitor personnel dose from external exposure. In this paper, dose response of OSL dosimeters in terms of Hp(10) to Cs‑137 gamma and 80 kVp X‑ray radiation will be studied. The dosimeters were irradiated using Cs‑137 gamma and 80 kVp X‑ray to 0.5 mSv, 1 mSv, 3 mSv, 5 mSv, and 10 mSv at a distance of 200 cm, and all of them were subsequently read. Half of the dosimeters that were previously irradiated with a dose of 1 mSv and 5 mSv were read 30 times. The other half of the dosimeters were re-read on day 30 and day 60 from the initial reading. The study shows that relations between measured dose and exposure dose for Cs‑137 gamma and 80 kVp X‑ray irradiation are linear with correlation coefficients (R2) of 0.9997 and 0.9987, respectively. When the OSL dosimeters were read repeatedly, a dose reduction for each reading occured by 0.4 % and 0.5 % on Cs‑137 gamma and 80 kVp X‑ray, respectively. Dose reading on day 60 after Cs‑137 gamma irradiation showed fading of 3.6 % and 2.7 % on OSL dosimeter exposed to 1 mSv and 5 mSv, respectively, whereas fading effect on 80 kVp X‑ray irradiation showed values of 5.9 % and 8.8 % for the two doses

Determination of the Diagnostic Reference Level (DRL) in Samarinda Hospitals

The diagnostic reference level (DRL) is a form of investigative level used as a tool to help optimize protection to radiation exposure for diagnostic and interventional procedures. The purpose of this study was to determine the local DRL values for the examination of the abdomen, thorax, and head at radiology installations. The modality used was 128-slice CT scan. The numbers of patients whose data were used were 200 for abdominal examinations, 160 for thoracic examinations, and 100 for head examinations. Overall, the total patient whose data was used was 460. Data processing in this study was carried out with a quantitative analysis technique, namely descriptive statistics. This analysis technique used secondary data obtained from the results of recaptures or archival books for examination of the abdomen, thorax, and head. Data processing was carried out with a measure of diversity through the calculation of the third quartile in the data distribution. It was assumed that 75 % of patients performed examinations with a common diagnosis. The results of these calculations are visualized in the form of graphs of the relationship of computed tomography dose index volume (CTDIvol) with the number of patients and a graph of the relationship of dose length product (DLP) with the number of patients. In the abdominal examination, a CTDIvol of 12 mGy and a DLP of 1545.5 mGy·cm. In the thoracic examination, a CTDIvol of 11 mGy and a DLP of 903 mGy·cm were obtained. For the head examination, a CTDIvol of 34.25mGy and a DLP of 2190.25 mGy·cm were obtained. The conclusion obtained from this study is that the DRLs are relatively low, but they still need to be optimized by medical physicists