Patent 7916825 was granted and assigned to KEPCO Nuclear Fuel on March, 2011 by the United States Patent and Trademark Office.
The present invention relates to a fuel rod of a nuclear fuel assembly having a vase-like compression spring adapted to increase the internal volume thereof wherein when the vase-like compression spring is inserted into a cladding tube, it has a relatively smaller volume occupied inside the fuel rod when compared with the existing coil type compression spring, such that the vase-like compression spring can ensure a sufficient space portion receiving the fission gases generated during the operation of the fuel rod, thereby increasing the burn-up performance of the fuel rod and the mechanical integrity thereof.