The comparison between calculated and measured dose rates of the cask for 12 spent fuels has been performed and this result confirms the shielding integrity of KN-12 transport cask to transport the spent fuel with safe. In February 2007, the dose rate measurements of KN-12 cask were performed in the spent fuel decontamination pit at the KORI Nuclear Power Plant in Korea. The general specifications of spent fuels being loaded into the cask were a burnup of around 33 GWD/MTU, an initial enrichment of 3.4 wt% and cooling times ranging from 15.8 years to 17 years. The discrete measurements were performed at several points for acquiring axial and radial dose rate profiles along the cask’s surface. All calculated and measured values showed the far less than dose rate requirements of 2000 μSv/h. The C/E ratios for neutron cases were generally about 1.0~2.8 except for the trunnions regions at cask’s side. The C/E ratios in gamma ray cases were about 1.1~2.7 at cask’s side. By this program the shielding integrity ...