The present study is an application of a radiochemical procedure using alpha spectrometry technique for determination of uranium isotopes ²³⁸ U,²³⁴ U, and ²³⁵ U on 13 granitic samples. These samples were collected from Gabal Gattar area, Northeastern Desert, Egypt. The collected samples were digested using microwave technique with aqua regia and spiked with ²³² U for chemical yield and activity calculation. Separation of uranium isotopes from the samples was done by Dowex 1 × 4 (50–100 mesh) resin followed by source preparation using microprecipitation technique. The concentrations of ²³⁸ U were ranged between 28.9 ± 0.9 and 134.8 ± 1.8 Bq/g, and the ²³⁴ U concentrations were between 24 ± 0.6 and 147.7 ± 2.2 Bq/g. For the ²³⁵ U, the activity concentrations were between 1.3 ± 0.2 and 6.7 ± 1.2 Bq/g. The activity ratio of ²³⁴ U/²³⁸ U was calculated and varied from 0.80 to 1.30.

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Studies on the response of 0.4 mm and 0.8 mm thick Teflon embedded CaSO₄:Dy discs are carried out using different beta sources having energy ranging from 0.224 to 3.54 MeV. Angular dependence of the response for 0.4 and 0.8 mm thick thermoluminescence (TL) discs was also studied for ⁸⁵ Kr and ⁹⁰ Sr/⁹⁰ Y beta sources. The ratio of the response of the open disc to that under 1.5 mm thick Perspex filter (D_Open/D_Perspex) was estimated for 0.4 and 0.8 mm thick TL discs in the energy range from 0.689 to 3.54 MeV. The evaluation of (D_Open/D_Perspex) ratio is necessary as same is used to estimate the energy of beta particles and to apply appropriate correction factor while evaluating beta dose. In addition to above, the optical density and transmission characteristics for 0.4 and 0.8 mm thick Teflon and CaSO₄:Dy Teflon embedded discs are also reported.

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Urea breath test (UBT) is commonly used diagnostic test for detecting the presence of Helicobacter pylori bacteria in the stomach. The patient undergoing the UBT ingests one microcurie of urea capsule containing labeled carbon-14. After ingestion of the capsule, the patient blows into a trapping solution. H. pylori bacteria in the stomach releases enzyme urease which breaks urea capsule to release carbon dioxide tagged with carbon-14 in the exhaled breath. Carbon-14 in the trapping solution is counted in liquid scintillation counter. In this study, 261 patients suspected of H. pylori infection had undergone UBT. It was found that 52% of the patients tested positive for H. pylori infection. No significant difference observed between various age groups. There was no statistically significant difference between the infection rates in males and females.

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In the present study, intensity-modulated radiotherapy (IMRT) commissioning has been validated as per the task group report 119 (TG119) of the American Association of Physicists in Medicine (AAPM). The plans have been done on structure and computed tomography scanned data set downloaded from the AAPM website. IMRT test planning has been performed to achieve conformed dose and dose distribution similar to that described in the AAPM TG119 report. Point dose measurements with ionization chamber have been taken on solid water phantom at a depth of 7.5 cm. Measurements were performed in two locations, i.e. at target volume and low dose avoidance structure, with planned machine parameters. Gamma evaluation of dose distribution produced by each field has also been done individually using electronic portal imaging device (EPID). Overall mean deviation obtained for ion chamber measurement was −0.012 (standard deviation [SD]: 0.015) with confidence limit (CL) 0.043 and −0.0012 (SD: 0.009) with CL 0.020 in high-dose region and low-dose region, respectively. Overall mean gamma passing in portal dosimetry calculated specifically for EPID has been observed 99.5% with SD 0.33 and CL 1.13. The results obtained for ion chamber dosimetry and portal dosimetry are much better than those reported in the AAPM TG119 report. Better results in gamma evaluation further reduced CL for EPID users.

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⁸⁵Kr a fission product noble gas is released into environment through stack at reprocessing plants during dissolution of spent fuel. Dual GM tube based online monitoring system having efficiency 0.5% for ⁸⁵Kr is used for quantification of ⁸⁵ Kr activity released through stack. Efficiency calibration of online monitoring system requires use of standard ⁸⁵Kr source which is not readily available. As per safety regulations periodic efficiency calibration of Krypton monitoring system is required to be done at least once a year. This paper presents an indigenously developed methodology for efficiency validation of krypton monitoring system using portable HPGe gamma spectrometer.

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Baseline radioactivity levels of naturally occurring radioactive materials within the operational area and surrounding communities of Akyem Gold Mine of Newmont Golden Ridge Limited of Ghana were determined based on direct gamma-ray spectrometry to quantify the radionuclides of interest, namely,²³⁸ U,²³² Th, and ⁴⁰ K in soil samples. The average activity concentrations of ²³⁸ U,²³² Th, and ⁴⁰ K in the soil samples were 11.90, 11.39, and 139.71 Bq/kg, respectively. For the water samples, the concentration values of gross-alpha and gross-beta for all the water samples were below the Ghana Standards Board (now Ghana Standards Authority) and World Health Organization recommended guideline values for drinking water quality. The annual average effective dose to the public due to gamma ray exposures from the soil samples was estimated to be 0.03 mSv which is below the UNSCEAR 2000 average reference level of 0.07 mSv for public exposure control. The results obtained in this study also show that radiation levels are within the natural background radiation levels found in literature and compare well with the results of similar studies in Ghana.

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Bioassay is the preferred individual monitoring technique for radiation workers handling phosphorus-32 (³² P), a pure beta emitter (β_max = 1.71 MeV) with 14.3 day half-life. The method standardized at Bioassay Laboratory, Trombay and in use for this purpose includes estimation of ³² P in urine by coprecipitation with ammonium phosphomolybdate followed by gross beta counting. In this study, the feasibility of Cerenkov counting for detection of ³² P in bioassay samples was explored, and the results obtained were compared with the conventional gross beta technique.

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Cleanup (CU) demineralizer of TAPS 1 and 2, containing mixed bed resins, is used to maintain reactor water chemistry. Once the bed is saturated, spent resin needs to be transferred to resin fixation facility for fixation and subsequent disposal in near-surface disposal facility. This is done by transporting the spent resin in a shielded resin transportation cask (SRTC) from radwaste building. The SRTC was manufactured with shielding thickness, based on methodology proposed by Rautela et al., “Shielding adequacy of proposed cask for transporting TAPS 1 and 2 CU spent resins.” Extensive radiation monitoring was carried out during the entire transfer and transportation process. Observed radiation levels on cask surface were within the accepted and calculated radiation levels. This paper describes verification methodology proposed by Rautela et al. and health physics operating experience during first CU spent resin transfer process at TAPS 1 and 2.

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