Basic requirements for radiation-shielding materials

Almost all materials offer some degree of shielding against X-rays and gamma rays. The higher the material's density, the greater its shielding capability. Consequently, if low-density materials are used, achieving the same level of protection requires significant structural thickness, thereby reducing the building's usable floor area.

Of course, specific projects require a comprehensive assessment that balances factors such as material availability, ease of construction, and cost-effectiveness. Shielding against neutron radiation requires not only heavy elements but also an abundance of light elements. High-energy fast neutrons are decelerated by high-density materials; however, for lower-energy intermediate neutrons, deceleration is effectively achieved only by hydrogen-rich materials. Since hydrogen is abundant in water, substances containing water of crystallization or chemically bound water can serve as "chemical guardians" against neutron flux.