Abstract: In order to meet the shielding requirements of gamma rays at radiation hot spots during outage and maintenance of nuclear power plants, a new flexible shielding composite material was developed by mixing vulcanization process, with polymethyl-vinyl siloxane rubber as matrix and heavy metal lead as functional filler. The shielding effect and mechanical properties of rubber-based composite with different lead powder content and particle size were studied. The experimental results show that the shielding performance of materials with the same thickness increases with the increase of lead powder content, and the particle size of 300 mesh lead powder is more conducive to the dispersion of lead powder in the matrix. The shielding performance of gamma rays is tested with ¹³⁷Cs and ⁶⁰Co collimated radiation. The density, tensile strength and hardness of composites increase with the increase of lead content, while the elongation at break decreases with the increase of lead content. By carrying out the demonstration application in nuclear power plants, it is proved that the installation of customized shielding materials can be quickly completed and the collective dose can be effectively reduced.

Key words: flexible, shielding, composite material, lead