The shielding properties of the ordinary concrete reinforced with innovative nano polymer particles containing PbO–H3BO3 for dual protection against gamma and neutron radiations

Highlights: • An innovative nano polymer based on PbO–H₃BO₃ was proposed for dual protection in mixed fields. • The polymer was synthesized by an innovative chemical technique and PbO–H₃BO₃ was fabricated. • Instrumental analysis confirmed the reasonable bonds between elements. • The employment of PbO–H₃BO₃ nano particles enhanced the shielding properties of the ordinary concrete. • The employment of particles with low concentrations up to 5 wt% is recommended. Most of the neutron sources such as nuclear reactors and reaction based sources are considered as a mixed field of radiation where both of neutron and gamma particles are emitted directly from the source. In these cases some special techniques are required for an efficient radiation shield design. Usually different neutron and gamma absorbers are employed via successive layers leading to a massive bulky design. In this study, an innovative nano polymer particle containing simultaneous gamma and neutron absorbers has been proposed to simplify and compact the shield design. The synthesized polymer is based on the H3BO3 as the neutron absorber and the PbO as the gamma ray attenuator, leading to PbO–H3BO3 nano polymer particles. The average size, morphological structure, functional groups and thermal properties of the synthesized polymer were characterized by instrumental techniques. The Monte Carlo simulations (MCNP4C) as well as the experimental methods have been employed to investigate the shielding properties of the ordinary concrete reinforced with PbO–H3BO3 filler particles. The simulation results showed that the employment of nano sized particles has a superior advantage over the micro ones for the neutron shielding. However, for the gamma shielding there are no important differences between the nano and micro sized particles and both of them increase the mass attenuation coefficient, significantly. A semi-saturation effect was observed for weight fractions more than 5 wt% of filler particles. Dozens of concrete slab samples reinforced with nano sized PbO–H3BO3 filler particles have been prepared for experimental studies. The mass attenuation coefficients as well as HVL values of samples were determined using some well-known gamma sources and NaI(Tl) scintillation detector. The results showed that the employment of 5 wt% PbO–H3BO3 reduces the HVL by 38% at 511 keV and 24% at 1332 keV. The experimental results endorsed the simulation study on the effectiveness of proposed innovative nano polymer particles for concrete shielding reinforcement.