Actually, some plastics are radiation shielding and they're off the shelf. First link has them by the palette it seems. https://marshield.com/borated-polyethyl

Actually, some plastics are radiation shielding and they're off the shelf. First link has them by the palette it seems. https://marshield.com/borated-polyethylene-neutron-shielding https://marshield.com/borated-polyethylene-neutron-shielding https://www.sciencedirect.com/science/article/abs/pii/S0168583X06008822 https://www.sciencedirect.com/science/article/abs/pii/S01685...