A cask liner includes a hollow cylinder comprising a boron-containing composition. The hollow cylinder has no longitudinal joints. The hollow cylinder may be formed as a single unit by isostatic pressing, for example by hot isostatic pressing (HIP) of a blend of a boron-containing powder and an aluminum or aluminum alloy powder which is blended by mechanical alloying. Casked nuclear fuel includes a nuclear fuel rod comprising uranium, which is disposed in or extends through the hollow cylinder of the cask liner.