HANDLING AND TRANSPORT SYSTEM USED FOR SPENT FUEL FROM THE THTR 300 MW NUCLEAR POWER STATION

After reaching the reference bumup, the spherical spent fuel elements of the thorium high temperature reactor are put into cans using a special filling device and then temporarily stored in the reactor building, with 2100 spent fuel elements per can. The cans are sealed with a press-fitted lid and have a leaktightness of approximately 10 - 4 mbar · L/s. These cans are then lowered by means of a crane equipped with a can grapple through an opening in the ceiling into the loading station. Here the shipping and storage cask is ready for loading. The cask hangs in a special trolley on rails. Under observation through a shielding window, and with camera monitoring, the cans are lowered into the cask. Still at the loading station, the primary lid is placed on the cask by remote control. After this, further handling is carried out at a second station outside of the loading station, where the secondary lid is assembled. These procedures are also either fully or partially automated. At the third station in this handling chain, the trolley drives to the shipping carriage, where the transfer of the cask takes place by means of a remote-controlled hoisting crane. The process of finally readying the cask for shipment is similarly automated. The handling procedure is designed to be able to smoothly perform approximately 100 cask loadings per year. Transport units consisting of two shipping carriages, with a total of six casks in each case, have been consuucted. The transfer to an external facility will be performed by the national railway system of the Federal Republic of Germany. Particular emphasis was placed in the design on minimizing the collective radiation dose of the service personnel. The design of the cask itself and its peripheries on the shipping carriage meets the regulations for the shipping of Type B(U) packagings.