Neutron and gamma radiation shielding properties
High performed new heavy concrete samples were designed and produced that absorption parameters were determined for gamma and neutron radiation by using Monte Carlo Simulation program GEANT4 code. In the sample production, many different materials were used such as; chromite (FeCr2O4), wolframite [(20Fe,80Mn) WO4], hematite (Fe2O3), titanium oxide (TiO2), aluminum oxide (Al2O3), limonite (FeO (OH) nH2O), barite (BaSO4), materials. Furthermore, calcium aluminate cement (CAC) was utilized for high temperature resistant. In the current study, five different new heavy concrete samples were produced then physical and chemical strength of them tested. High-temperature-resistant tests were made at 1000°C and good resistance against high temperature was observed. Neutron equivalent dose measurements were made for by using 4.5 MeV energy 241Am-Be fast neutron source. Results compared with paraffin and conventional concrete. It was found that the new heavyweight concretes had the better absorption capacity than paraffin and conventional concrete. Gamma radiation absorption measurements also were carried out at the energies of 160, 276, 302, 356, and 383 keV by using 133Ba point radiation source. It has been suggested that the new produced concretes can be used for radiation safety in the nuclear applications.
Radiation is often used in applications such as in energy production, in medicine diagnosis and treatment, in material research and investigation. In addition, it is also used in such areas as agriculture, archeology (in carbon determination), space exploration, military, geology, and many others (U.S. NRC, 2010). Radiation leaks may occur during these applications (Lamarsh, & Baratta, 2001); therefore, it must be properly shielded. In radiation shielding works, conventional materials such as concrete, steel, alloy, ceramic, glass, and polymers are widely used (Aygün et al., 2019; Kumar, Sayyed, Dong, & Xue, 2018; Sayyed, Akman, Kumar, & Kaçal, 2018). In these studies, concrete is among the most widely used materials (Li et al., 2017). Concrete is a composite material which glued in such a way that aggregate particles (sand, gravel, stone, and filler) with cement or a binder. Traditional concrete is not as effective in nuclear shielding material radiation, but it is a very common used building material. The traditional concrete lead bricks for radiation shielding characteristic may vary and is dependent on the chemical composition of the concrete. New types of concrete samples have been developed by different the aggregated used for preparing concrete, depending on the available natural and artificial materials (Mukhtar, Shamsad, Al-Dulaijan, Mohammed, & Akhtar, 2019; Chen, 1998). Heavy concrete is the most common material used in radiation shielding equipment. Heavy concrete is obtained by adding high-density aggregates into normal concrete. Normal-weight concrete density varied between 2200 and 2450 kg/m3 while heavy concrete’s density is ranging from about 2900 and 6000 kg/m3 (Nawy, 1997). Some natural minerals such as hematite, magnetite, limonite, serpentine, siderite and barite can be used as aggregates in heavy concrete production. In literature, numerous experimental and theoretical researches have been conducted to develop new heavy concrete. Different minerals like siderite, limonite were used to produce heavy concrete in order to provide gamma radiation shielding. It was reported that the gamma radiation absorption capacity of heavy concretes is high (Basyigit et al., 2011). Boron-containing multi-layered new heavy concretes were produced and radiation shielding properties were determined. It is reported that these concretes are very high in 14 MeV neutron absorption capacity (Sato, Maegawa, & Moshimatsu, 2011). In a different study, some metal oxides such as Al2O3, AS2O3, BaO, CaSO4, CdO, Cr2O3, CuO, Fe2O3, K2O, MgO, MnO, Na2O, NiO, P2O5, PbO4, SrO, TiO2 was used in the heavy concrete production, and it was stated that the use of these new heavy concretes in nuclear reactors is appropriate (Abdo, 2002; Erdem, Baykara, Doğru, & Kuluöztürk., 2010; Mortazavi, Mosleh-Shirazi, & Baradaran Ghahfarokhi et al., 2010). Seltborg et al.produced heavy concretes by using, such as calcium (Ca), strontium (Sr), barium (Ba), radium (Ra) magnesium (Mg) elements. They determined these heavy concretes can be used to shield gamma and neutron radiation in nuclear reactors (Seltborg et al., 2005). In the present study of tungsten oxide (WO3) gamma radiation mass attenuation coefficient in the concrete, the effect on the coefficient was investigated. Appropriate geometry found by using MCNPX and XCom simulation programs. It is found that shielding properties when nanoparticle WO3 doped in concrete more than microparticle WO3 (Tekin, Singh, & Manici, 2017). In another study, high-density concrete (ρ = 4.71 g/cm3) was made by using steel balls and in aggregate
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