A corrosion-resistant tube (commonly aluminum, zirconium alloy, or stainless steel) surrounding the reactor fuel pellets which provides protection from a chemically reactive environment and containment of fission products.
The material surrounding the core of a fiber optic cable. The cladding must have a lower index of refraction than the core in order to contain the light in the core.
Cladding is one of two pieces that make up a fiber optic cable; the other piece is a glass core. A plastic coating covers the fiber. The glass cladding has a lower refractive index than the core, and reflects the light signal as it propagates down the fiber.