Annulus gap shielding snakes are designed to sit or be wedged into the gap created between the canister and transfer cask. NPO offers annulus gap snakes with lead or T-Flex Tungsten. High temperature covers are placed on the shielding to protect from weld splatter.

T-Flex® snakes are wedged shaped to ensure the fit snug into the gap without falling all the way down. Due to the properties of T-Flex®, a plant can expect dose reduction not just with gamma radiation, but also with neutron radiation. All are custom made to fit the exact canister design dimensions.