Mechanical properties and attenuation ability of biowaste-derived CaCO₃ for radiation shielding applications

Lead, the common radiation shield, poses significant risks to medical personnel's organs despite its shielding properties. Concrete, increasingly utilised as another radiation barrier than lead, shifts towards sustainability due to depleting resources like cement. This research evaluated fabricated concrete samples' mechanical stability and radiation shielding using EpiXS software for gamma radiation and a medical linear accelerator for x-rays. Local green mussel shells underwent cleaning and calcination at 550°C for 2 h and then pulverised and sieved for uniformity. Concrete cylinders and slabs were cast with 2, 4, 6, 8, and 10% cement replacement for mechanical and attenuation tests. Debris from mechanical tests was pelletised for XRF analysis. Results indicated 2% green mussel shell powder (GMSP) concentration optimised concrete's mechanical properties. EpiXS analysis showed almost the same N_eff trend for control and all concentrations, while GMSP4 consistently produced the highest Z_eff for all energies. MAC values peaked at GMSP4, and TVL was lowest at GMSP8. In linear accelerator tests, GMSP4 had the lowest TVL yield. Future studies should explore MRI and XRD analysis for powder characterisation and consider larger slab surfaces.