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The aim of this study is to investigate the radiation shielding properties of novel concrete samples with bulk Bi2O3 and Bi2O3 nanoparticles (Bi2O3 NP) incorporated into its composition. The mass attenuation coefficient of the concrete samples without Bi2O3 and with 5 and 7 wt% bulk Bi2O3 were experimentally determined and were compared against values obtained using the XCOM and Geant4 simulations. Both methods greatly agree with the experimental values. The linear attenuation coefficients (LAC) of blank concrete (C-0), concrete with 5% bulk Bi2O3 (C-B5), and concrete with 5% nanoparticle Bi2O3 (C-N5) were determined and compared at a wide energy range. We found that the LAC follows the trend of C-0 < C-B5 < C-N5 at all the tested energies. Since both C-B5 and C-N5 have a greater LAC than C-0, these results indicate that the addition of Bi2O3 improves the shielding ability of the concretes. In addition, we investigated the influence of nanoparticle Bi2O3 on the LAC of the concretes. The half-value layer (HVL) for the concretes with bulk Bi2O3 and Bi2O3 nanoparticles is also investigated. At all energies, the C-0 has the greatest HVL, while C-N15 has the least. Thus, C-N15 concrete is the most space efficient, while C-0 is the least space efficient. The radiation protection efficiency (RPE) of the prepared concretes was found to decrease with increasing energy for all five samples. For C-0, the RPE decreased from 63.3% at 0.060 MeV to 13.48% at 1.408 MeV, while for C-N15, the RPE decreased from 87.9 to 15.09% for the same respective energies. Additionally, C-N5 had a greater RPE than C-B5, this result demonstrates that Bi2O3 NP are more efficient at shielding radiation than bulk Bi2O3.

This work aims to experimentally report the radiation attenuation factors for four different clays (red, ball, kaolin and bentonite clays) at four selected energies (emitted from Am-241, Cs-137, and Co-60). The highest relative difference in the mass attenuation coefficient (MAC) is equal to −3.02%, but most of the other results are much smaller than this value, proving that the experimental and theoretical data greatly agree with each other. From the MAC results, the shielding abilities of the clay samples at 0.060 MeV follow the order of: bentonite > red > ball > kaolin. Thus, at low energies, the bentonite clay sample provides the most effective attenuation capability out of the tested clays. The half value layer (HVL) increases as energy increases, which suggests that, only a thin clay sample is needed to sufficiently absorb the radiation at low energies, while at higher energies a thicker sample is needed to shield the same amount of high energy radiated. Furthermore, bentonite clay has the lowest HVL, while the kaolin clay has the greatest HVL at all energies. The radiation protection efficiency (RPE) values at 0.060 MeV are equal to 97.982%, 97.137%, 94.242%, and 93.583% for bentonite clay, red clay, ball clay, and kaolin clay, respectively. This reveals that at this energy, the four clay samples can absorb almost all of the incoming photons, but the bentonite clay has the greatest attenuation capability at this energy, while kaolin clay has the lowest.

In the present study, 52 sediment samples were collected from 14 sites along the area extending from west of Alexandria (El-MAX) to the eastern side of the Rosetta promontory (the terminal of the Nile River with the Mediterranean Sea). The collected samples were analyzed for radioactive contents. 226 Ra, 228 Ra, 40 K and 137 Cs were detected. The distribution of radionuclide activity and mass concentrations of Th and U displayed a specific pattern that reflects the mineralogical formations and beach stability. Radiological hazards were investigated by calculating the following radiological parameters: the radium equivalent, radiation hazard index and annual effective dose. It was observed that the levels of radiological parameter are higher in eastern locations than in western ones. In addition, the western side displayed radiological parameters higher than the recommended world-wide values.

Musandam peninsula located at one of the most important marine strait overlooking the Arabian/ Parisian Gulf. Environmentally, this area is characterized by its primitivistic status and vulnerable to any natural or manmade disturbances. This work presents the second phase of a comprehensive radiation measurement in Musandam Peninsula environment amid to investigating the presences of depleted uranium (DU) residues and assessing the current levels of 226 Ra, 228 Ra, 40 K and 137 Cs in surface soil of coastal area. For this purpose, thirty representative soil samples were collected and analyzed for 235 U using gamma rays spectrometry and for total U using ICP-OES techniques. Results revealed that the range of isotopic abundance of 235 U was (0.70%e0.77%) with an average of 0.72%, confirming the detected uranium is naturally originated from the geological formations of investigated soil. Additionally, the values of Th/U ratios were calculated to be ranged from 0.37 to 1.95 with an average of 1.5 indicating the dominant geological formations are metamorphic sedimentary rocks that contain low levels of Th. The averages of radioactivity levels of NORMs indicated 16.02 Bqkg À1 , 7.83 Bqkg À1 and 174.03 Bqkg À1 for 226 Ra, 228 Ra, and 40 K respectively. The average of areal concentrations for 137 Cs was 2481.5 Bqm À2 ranges from 1040 Bq/m 2 to 9225 Bqm À2. The total external annual effective dose from all measured radionuclides was 23 mSv 237 Cs contribution is 1% while 238 U, 232 Th series and 40 K radionuclides contributions are 32%, 28% and 39% respectively. Radium equivalent, external, and internal radiation hazard indices indicate no radiological anomaly.