KN-18 Spent Nuclear Fuel Transport Cask

KN-18 cask as shown in Fig.1 was designed to transport up to 18 PWR spent nuclear fuel assemblies in compliance with the requirements of Korea and IAEA regulations for Type B(U)F package. It provides containment, radiation shielding, structural integrity, criticality control and heat removal for normal and accident conditions of transportation. CE 16x16 fuel with maximum enrichment of 5.0 wt.%, maximum burnup of 60 GMWD/MTU and minimum cooling time of 9 years can be loaded and transported under both dry and wet conditions. Cask body of a thick forged carbon steel inner shell, a neutron shielding layer and a stainless steel outer shell is closed by two stainless steel lids. Neutron shielding material is installed surrounding the inner shell in the external shell with longitudianl aluminum heat trasnfer fins. Stainless steel fuel basket with neutron absorbing plates to accommodate 18 PWR fuel assemblies provides support of the fuel, control of criticality and path to dissipate heat. Impact limiters to absorb the impact energy under hypothetical accident conditions are attached at the top and bottom side of the cask during transportation. Carbon steel surfaces were covered by stainless steel cladding for corrosion protection and external cask surfaces were treated by buffing to facilitate decontamination work. Handling weight loaded with fuel is 104 tons and total transportation weight including impact limiters is 126 tons. The cask was licensed in accordance with Korea Nuclear Safety Act. Total four casks were fabricated in accordance with ASME Sec.III Div.3 and legal fabrication examination was undergone.