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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. • 177Lu could be removed from aqueous systems in a relatively short time, with an efficiency of about 90%, by Montmorillonite. • The adsorption mechanism is predominantly ion exchange and ion coupling, and the interactions between Lu3+ ions. • The adsorption of Lu3+ is in agreement with the pseudo-second-order kinetic model and the Freundlich isotherm equation. [ABSTRACT FROM AUTHOR] more...

Abstract Perlite mineral contains relatively high water and in general hydrated obsidian forms the perlite which is mainly an amorphous volcanic glass. Photon attenuation properties for different concrete types including natural perlite mineral and B 4 C have been experimentally investigated by using different radioactive point sources at 81, 276, 303, 356, 384, 662, 1173, 1275 and 1333 keV. SEM and EDAX analyses were carried out to control the crystal structure of the selected concrete types. In this work, HPGe detector based on gamma spectrometer was employed for all experiments. The results revealed that among the prepared concrete samples, the P6 concrete sample has the lowest HVL and MFP values and thus, having best ability to attenuate gamma rays in comparison to the other prepared concretes. [ABSTRACT FROM AUTHOR] more...

In this work, it was aimed to determine the potential bacterial strains that can be bioremediated of the radioactive uranium. The experimental analysis was made in gamma spectrometry. Uranyl acetate (CH 3 COO) 2 UO 2.2H 2 O was used as the radioactive material. The radioactive solutions containing bacterial strains (P. chlororaphis (3N17-10); B. licheniformis (1N17-3); L. casei (NM-25); L. plantarum (NM-10); L. brevis (NM-26); L. lactis (NM-41); L. curvatus (NM-1); L. pentosus (NM-38); L. coryniformis (NM-22) and B. subtilis (N-28)) were prepared. A high purity germanium detector with a resolution of 490 eV at 122 keV was used to measure the photon intensities emitted from the radioactive solutions. The removal percentage and adsorbed amount of the investigated samples were determined. The results showed that P. chlororaphis have got an excellent sorption capacity for uranium removal. • Uranium could be removed from aqueous systems with an efficiency of about 95%, by adsorption using bacterial strains. • The adsorption mechanism of radioactive uranium for the bacterial strains is predominantly ion exchange and ion coupling. • P. chlororaphis have got an excellent sorption capacity for uranium removal. [ABSTRACT FROM AUTHOR] more...

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, 40 K 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 40 K 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 40 K compounds with these properties are much suitable for to use as verifying sources or gamma calibrators. [ABSTRACT FROM AUTHOR] more...

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. [ABSTRACT FROM AUTHOR] more...

The radiation shielding properties of some ceramic materials have been measured and obtained results were compared with the simulation. Gamma rays with energy of 662, 1173, and 1332 keV produced from 137Cs and 60Co radioactive sources were utilized in the experimental part of this work to measure linear attenuation coefficients (LAC). A gamma spectrometer with a 3″ × 3″ NaI(Tl) detector, high-voltage electrical components, a preamplifier, an amplifier, and 16384-channel Multi-Channel Analyses (MCA). For simulation the Monte Carlo method to compute and evaluate the linear attenuation coefficients of ceramic materials employed in the human body as synthetic or natural materials. In the simulations conducted with the Gamos 6.2 software, a mono-energetic point photon source geometry between 1 keV and 15 MeV was employed in the computational phase of the investigation by focusing a parallel photon beam toward the absorber material. • The radiation shielding properties of some ceramic materials have been measured and compared with the simulation. • Gamma rays with energy of 662, 1173, and 1332 keV were used for experiment. • A gamma spectrometer system with a 3″ × 3″ NaI(Tl) detector was used for experiment. • For simulation the Gamos Monte Carlo code was used to obtain the linear attenuation coefficients. • In the simulations, a mono-energetic point gamma source geometry between 1 keV and 15 MeV. [ABSTRACT FROM AUTHOR] more...

Simulation is a simple method that allows for facile estimation of a detector response function when the specifications of the investigated sample and the sample-detector geometry are known. In this study, the dependence of the full-energy peak efficiency on the sample and detector specifications was studied via analytical techniques and the Monte Carlo approach in the energy range of 150–2000 keV for a well-type measuring geometry, and a semi-empirical model was developed. The modeling of the detector efficiency is described in detail. The compute results were compared with experimental data, and comparison of the calculated efficiencies with the measured values indicated that the deviations between the calculated and experimental efficiencies were mostly less than ±10%. Therefore, the simulation model appear to be suitable for routine environmental radionuclide analysis when uncertainties of up to 10% are acceptable for energies between 150 and 2000 keV. [ABSTRACT FROM AUTHOR] more...

The photon response characterization of a Ø 25.4 mm × 25.4 mm solution-grown stilbene based detector assembly was performed in the 59 keV–4.44 MeV energy range. Energy calibration was carried out using not only direct measurements but also via coincidence measurements in order to obtain more reliable results. Both methods gave consistent results. To establish an accurate model of the detector, its energy resolution was determined and included in MCNPX-PoliMi simulations. This model served to compute the gamma-response matrix in the 0.1–7.3 MeV energy range. This matrix was used as an input of the GRAVEL spectrum unfolding code when attempting to unfold the measured spectra of well-known sources. Despite a few discrepancies concerning peak intensities, the main gamma peaks were successfully identified in the 0.059–4.4 MeV energy range, thus confirming the utility of solution-grown stilbene as a low-resolution gamma spectrometer, especially for identifying the gamma component in neutron fields. [ABSTRACT FROM AUTHOR] more...

Abstract: In recent years the k 0-NAA method has been applied and developed at the 15MW Es-Salam research reactor, which includes: (1) the detection efficiency calibration of γ-spectrometer used in k 0-NAA, (2) the determination of reactor neutron spectrum parameters such as α and f factors in the irradiation channel, and (3) the validation of the developed k 0-NAA procedure by analysing SRM, namely AIEA-Soil7 and CRM, namely IGGE-GSV4. The analysis results obtained by k 0-NAA with 27 elements of Soil-7 standard and 14 elements of GSV-4 standard were compared with certified values. The analysis results showed that the deviations between experimental and certified values were mostly less than 10%. The k 0-NAA procedure established at Es-Salam research reactor has been regarded as a reliable standardization method of NAA and as available for practical applications. [Copyright &y& Elsevier] more...

A NaI(Tl)-based gamma spectrometer for the analysis of geological materials was calibrated using the IAEA reference materials RGU-1, RGTH-1 and RGK-1. To simulate typical geological samples, two additional standards were prepared from aliquots of the three reference materials. The reproducibility of the instrument calibration factors (CFs) was tested by repeated measurements of the pure IAEA reference materials and the mixed samples in a reproducible counting geometry. The results were analysed using a two-way classification analysis of variance; it was found that the variance in the CFs is significantly higher between standards than it is between measurements. Allowance should be made for this when estimating uncertainties in measurements with the NaI(Tl) spectrometers. [Copyright &y& Elsevier] more...

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. • HPGe characteristics were obtained and optimized using a cost-effective procedure. • Geometry parameters of HPGe were determined using Monte Carlo simulation (MC). • Method of evolutionary algorithms was used for optimization in parallel with MC. • Results of this study can be used in both spectrometer development and calibration. [ABSTRACT FROM AUTHOR] more...

In this study, linear attenuation coefficients of concretes containing different rates of basalt-magnetite aggregates were measured for gamma energies of 511, 662, 835, 1173, 1275 and 1332 keV emitted from 22Na, 137Cs, 54Mn and 60Co radioactive sources respectively, using the gamma spectroscopy system containing NaI(Tl) detector. According to the ratio of basalt-magnetite aggregate used in concretes, the variation of linear attenuation coefficient was investigated. The measured linear attenuation coefficient (μ) results were compared with the theoretical values obtained using the XCOM code. Experimental and theoretical results were observed to be compatible with each other. In addition, using the experimentally obtained linear attenuation coefficients, Half Value Layer (HVL), Tenth Value Layer (TVL), Mean free path (MFP) and radiation protection efficiency (RPE) values were also determined. It can be seen from those of results that the linear attenuation coefficients are linearly related to the basalt-magnetite ratio in the concrete. While it is also linearly related to radiation protection efficiency (RPE), inverse linear relations have been observed for the values of Half Value Layer (HVL), Tenth Value Layer (TVL) and Mean free path (MFP). It can be concluded that the using basalt-magnetite as aggregate in concrete is an important material to develop concrete in terms of radiation shielding. [Display omitted] • Production of concrete. • Radiaion shielding of magnetite concrete. • Measurement by gamma spectrometer. • Comparison measured results with the XCOM calculation. [ABSTRACT FROM AUTHOR] more...

In present days new neutron detection methods are under developed due to the global shortage of 3 He and the toxicity of BF 3 . Neutrons can be indirectly detected by high-energy photons. The performance of a cylindrical NaI crystal, 4 in. diameter and 8 in. length as an indirect neutron detector has been investigated. Measurements were performed with 252 Cf source with bare and shielded NaI detector. With a proper converter and moderator structure for the NaI detector, the detection efficiencies and the minimum detectable activities are improved, making the method very interesting for security applications. The indirect detection of neutrons by photons has several advantages. First, this method can in principle be suited by any gamma spectrometer with only slight modifications that do not compromise with its gamma spectrometry measurements. Second, fission neutron sources and neutron generators can be discriminated thanks to their different gamma energy spectra, a discrimination easily done by a NaI spectrometer. [ABSTRACT FROM AUTHOR] more...