Neutron and gamma radiation shielding properties

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, & Ka?al, 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, Do?ru, & Kulu?ztürk., 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 the debris

of the demolished concrete buildings in the earthquake region in Fukushima. Good shield properties were determined

this of heavy concrete and it is shown that can be used in storage radioactive waste (Sanjay, Yusuke, Kimura,

Fujikura, & Araki, 2018). Heavy concrete was made using lead-zinc slag waste instead of sand which can be used

gamma radiation shielding. Shielding and strength properties were investigated of this concrete and compared with

conventional concrete. It is reported that lead–zinc slag waste concretes better radiation shielding and strength

characteristic than conventional concretes (Mohamed, 2017). Medical cyclotron is a system designed for

radiopharmaceutical production, which high-level radiation emit. Shielding wall thickness was calculated by using

Monte Carlo simulation when cyclotron system used to operate that may occur radiation. Consequently, for

shielding, radiation at 200-cm-thickness concrete wall need was determined (Jang, Kim, & Kim, 2017). Some mining

wastes suitable for heavy concrete production. For instance, Gallala et al. have produced new heavy concrete by

using barite-fluorspar mine waste (BFMW) aggregates and investigated their gamma radiation shielding, mechanical

strength properties. The results clearly showed when ratio 25% BFMW added to concretes has better gamma radiation

shielding and compressive strength properties than conventional concrete (Gallala et al., 2017). Tekin et al.,

using MCNPX code, demonstrated that high strength concrete containing nanoparticles of WO3 and Bi2O3 had enhanced

shielding capacity for gamma radiation (Tekin, Sayyed, & Issa, 2018). Five different concrete types were made

using magnetite aggregates and 0%, 2%, 4%, 6%, and 8% of titanium dioxide (TiO2) nanoparticles for nuclear power

plant shielding material. Some of the protecting parameters such as MAC (mass attenuation coefficients) HVL

(half-value layer), TVL (tenth value layer), and linear attenuation coefficients (LAC) were determined for 662,

1173, and 1332 ?keV energy of gamma ray used. It is reported, the significant effect on radiation shielding

properties occurred within 8% of TiO2 nanoparticles (Iman et al., 2019). Some natural minerals can be using heavy

concrete in production. Different concrete types which including natural perlite mineral and B4C have been

experimentally investigated and gamma radiation shielding parameters have been determined (Agar et al., 2019)

    In this study, new concrete samples were designed and produced using Monte Carlo simulation program Geant4

code. The production of heavy concrete for radiation shield was made based on the concrete production process such

as mixture proportion, ratio of water to cement, cement hydration. Furthermore, new concrete candidates with good

radiation shielding

ability at high temperature have been produced and it has been shown that raw materials such as chromite,

wolframite can be used in production.

    In Monte Carlo simulation program, the Geant4 code is used to determine the interactions between radiation and

materials. In addition, it can be used to predict nuclear events that may occur at the point of radiation and

detector interaction. Geant4 software is the most developed, for analyses biological effects of radiation-induced

and their modification nuclear shielding

engineering. Also, Monte Carlo program Geant4 to simulate can be used to predict the transport, accumulation

of incident particles through the walls of a nuclear power plant (Agostinelli et al., 2003). It is used in

applications in nuclear physics, particle accelerator designing, space investigation, and medical physics.

Detailed information can be found at www.Geant4.org.

    2.2. Sample preparation

    New heavy concrete samples were produced by using different natural aggregates such as chrome ore (FeCr2O4),

wolframite [(Fe,Mn)WO4], hematite (Fe2O3), limonite (FeO (OH) nH2O), barite (BaSO4). Nickel oxide (NiO) was used

to fill the pores that could form in the concrete. The chromium ore (FeCr2O4) mineral has a density of average

4.79 g/cm3 and it melts in temperature 1650–1660°C (Jay, Meegoda, Zhengbo, & Kamolpornwijit, 2007). The chrome

ore sample was taken from the Kayseri city Yahyal? district chrome mine. This chrome ore contains such minerals

53.19% Cr2O3, 16.80% MgO, 11.15%Al2O3, 15.11%Fe, 2.72%SiO2, 0.007%S, and 0.005% P according to Eti (Chromium

Ferrochrome Foundation). Wolframite is a mineral with a density of 7.1–7.5, average 7.3 g/cm3 and 11.70% MnO,

16.85% FeO, 71.46% WO3 including (Tolun., 1951). This ore was obtained from an Uluda? tungsten mine, which is

located in the province of Bursa and is approximately 2200–2300 m high from the sea. According to the pioneering

simulation work, both gamma and neutron radiation absorption cross-sectional values were determined higher in

chromite and wolframite minerals. Furthermore, these minerals have both refractory properties and high mechanical

strength and plenty of reserves. Therefore, these minerals were used in the production of heavy concrete.

Hematite, titanium oxide, aluminum oxide, limonite, siderite, barite, materials are always used materials for the

production of heavy concrete, but for that, the chromite and wolframite minerals are not very commonly used. The

usage of natural chromite and wolframite minerals provided will be with this work in the nuclear industry.

Chromium oxide (Cr2O3) was used to fill capillary cavities that may form in concretes. When concrete components

were selected, the high macroscopic cross-sectional values were taken into account.