Method of setting up fuel assemblies

Purpose: To prevent scratches on the surface of a fuel rod and enable rapid set up by utilizing the slidability of ice by inserting a fuel rod previously formed at the surface with thin ice film into each of the spaces in a channel. Method: Fuel rod is cooled in a refrigerator to -50C - -100C and stored. Then, the fuel rod is placed on a conveying passage and sprayed with pure water from a nozzle to form a thin ice film on the surface. The fuel rod is returned to the refrigerator to stabilize the thin ice film. Then, the fuel rod formed with the thin ice film is set up into each of the spaces in a square channel by utilizing the slidability of ice. Thereafter, ice is melted at room temperature and the rod is dried spontaneously. This can prevent scratches on the surfaces of the fuel rod and enables rapid set up of fuel assemblies utilizing the thin ice film as lubricant. (Yoshino, Y.)