Gas permeability and gamma ray shielding properties of concrete for nuclear applications

• The presence of serpentinite aggregates emerged as the most influential factor affecting gas permeability. • Porous zones around serpentinite affected strength, gas permeability, ITZ and radiation shielding properties of concrete. • Slag cement concrete exhibited reduced radiation shielding capabilities compared to OPC. • The relationship between gas permeability, the Half-Value Layer (HVL), and the density of concrete was demonstrated. • Research results enable to create effective concrete shields through limiting leaks and boosting nuclear safety. Concrete used in nuclear applications faces significant durability challenges due to degradation from radiation, thermal stresses, and chemical reactions. These issues highlight the critical need for impermeable concrete shields to prevent radioactive leaks and protect against harmful radiation. This study examines how concrete composition affects gas permeability and gamma radiation shielding properties. Three coarse aggregates—amphibolite (reference), magnetite, and serpentine—and two cement types (ordinary and slag) were tested, with concrete densities ranging from 2309 to 3538 kg/m 3 . Gas permeability was measured using a Cembureau-type constant head permeameter, and gamma shielding was assessed through the linear attenuation coefficient (µ) and half-value layer (HVL) at 137 Cs decay energies. The results revealed significant variations in gas permeability and gamma ray shielding based on aggregate and cement type, with observable relationships between gas permeability, HVL, and concrete density. The results obtained from the presented research will contribute to increasing the safety, durability and cost-effectiveness of concrete constructions and maintenance of nuclear facilities.