A nuclear flask is a shipping container that is used to transport active nuclear materials between nuclear power station and spent fuel reprocessing facilities.
Each shipping container is designed to maintain its integrity under normal transportation conditions and during hypothetical accident conditions. They must protect their contents against damage from the outside world, such as impact or fire. They must also contain their contents from leakage, both for physical leakage and for radiological shielding.
Spent nuclear fuel shipping casks are used to transport spent nuclear fuel[1] used in nuclear power plants and research reactors to disposal sites such as the nuclear reprocessing center at COGEMA La Hague site.