Containment Evaluation of the KN-12 Transport Cask

  • Published : 2003.12.30


The KN-12 transport cask has been designed to transport 12 PWR spent nuclear fuel assemblies and to comply with the regulatory requirements for a Type B(U) package. The containment boundary of the cask is defined by a cask body, a cask lid, lid bolts with nuts, O-ring seals and a bolted closure lid. The containment vessel for the cask consists of a forged thick-walled carbon steel cylindrical body with an integrally-welded carbon steel bottom and is closed by a lid made of stainless steel, which is fastened to the cask body by lid bolts with nuts and sealed by double elastomer O-rings. In the cask lid an opening is closed by a plug with an O-ring seal and covered by the bolted closure lid sealed with an O-ring. The cask must maintain a radioactivity release rate of not more than the regulatory limit for normal transport conditions and for hypothetical accident conditions, as required by the related regulations. The containment requirements of the cask are satisfied by maintaining a maximum air reference leak rate of $2.7{\times}10^{-4}^3s^{-1}$ or a helium leak rate of $3.3{\times}10^{-4}cm^3s^{-1}$ for normal transport conditions and for hypothetical accident conditions.


  1. IAEA Safety Standards Series No.TS-R-1, 'Regulations for the Safe Transport of Radioactive Material' (2002)
  2. ASME Boiler and Pressure Vessel Code, Section III, Division 3, 'Containment Systems and Transport Packagings for Spent Nuclear Fuel and High Level Radioactive Waste' (1998)
  3. US 10 CFR Part 71, 'Packaging and. Transportation of Radioactive Material' (1997)
  4. NUREG/CR-6487, Anderson, B.L., Carlson, R.W., and Fisher, L.E., 'Containment Analysis for Type B Packages Used to Transport Various Contents' (1996)
  5. ANSI N14.5, 'American National Standard for Radioactive Materials Leakage Tests on Packages for Shipment' (1997)