The effect of incorporated recycled low density polyethylene (LDPE) on the fast neutron shielding behaviour (FNSB) of clay matrix using MCNP and PHITS Monte Carlo codes

Abstract

In order to develop a cheaper, environmentally friendly and self-sustaining high hydrogen content material for fast neutron shielding, clay-polyethylene composites containing different weight fractions of recycled low density polyethylene (LDPE) were fabricated. The effect of the incorporated LDPE on the fast neutron shielding behaviour (FNSB) of the clay matrix was investigated using MCNP and PHITS Monte Carlo codes. This was done by evaluating the fast neutron effective removal cross section (ƩR), mean free path (λ) and the neutron yield of the fabricated composites. The obtained values of effective removal cross section ƩR for the composites range between 0.056 cm−1 and 0.079 cm−1, while the values of mean free path λ are between 17.857 cm and 12.658 cm. The results show that the effective removal cross section of the samples significantly increased, while the mean free path decreased as the weight fraction of recycled LDPE increased. This implies that the fast neutron shielding behaviour of the composites improves as the LDPE concentration increases in the clay matrix. The neutron yield of the composites obtained PHITS code follows similar trend.