Neutron and gamma attenuation in polyethylene and PVC mortars

Concrete is a basic building material widely used in radiation shielding. As water in ordinary concrete is only ∼6% by weight, fast neutrons undergo a medium to poor moderation process. Special types of mortar were developed in which polyethylene [(CH2)n] or PVC [(CH2-CH-Cl)n] pellets were used instead of coarse aggregates in ordinary concrete. Both of these polymers are rich in hydrogen and carbon moderator atoms. Preparation methods and resulting material properties are discussed