The material predominantly used for shielding and safety from hazardous nuclear radiation is:

Lead ($\text{Pb}$) is highly effective for radiation shielding against ionizing radiation like gamma rays and X-rays. This shielding efficiency is a result of its high density ($11.34{\text{g/cm}}^3$) and high atomic number ($Z=82$). These properties provide a high concentration of electrons per unit volume, which maximizes the scattering and absorption of hazardous high-energy radiation particles.