FUEL ASSEMBLY OF PWR WITH STATIONARY FUEL CAN AND MOVABLE FUEL CAN

摘要

The present invention relates to a nuclear fuel assembly of a pressurized water reactor with stationary fuel tanks and movable fuel tanks. 20 stationary nuclear fuel tanks are arranged along the outermost line while forming a square structure, 12 movable nuclear fuel tanks are arranged along the middle line while forming a square structure, and four stationary nuclear fuel tanks are arranged along the inner line while forming a square structure. Each stationary nuclear fuel tank includes six inner jacket lattice layers in the interior of an outer jacket pipe having a diameter from 31 to 34mm and has UO_2 pallet piles, which have each diameter from 9 to 10mm and are arranged therein while forming a regular hexagonal structure. Each movable nuclear fuel tank has an outer jacket pipe having a diameter from 31 to 34mm, and the interior of the outer jacket pipe is roughly divided into an upper area and a lower area. Similar to the stationary nuclear fuel tank, 6 inner jacket lattice layers are included in the lower area of the interior of the outer jacket pipe, and UO_2 pellet piles having each diameter from 9 to 10mm are arranged inside the inner jacket lattice layers while forming a regular hexagonal structure. Also, 5 inner jacket lattice layers are included in the upper area of the interior of the outer jacket pipe, and UO_2 pellet piles, which have each diameter from 9 to 10 mm, are arranged in the inner jacket lattice layers while forming a regular pentagonal structure. The UO_2 pellet piles in the regular pentagonal structure have each interval of 2mm from the inner jacket lattice layers so that the UO_2 pellet piles may move in the longitudinal direction of the nuclear fuel tank.