FUEL ASSEMBLY FOR BOILING WATER REACTOR

PURPOSE:To provide a fuel assembly for boiling water reactor which reduces the generation of subcool void, suppresses the lowering of core void fraction in the case coolant mixing is suddenly promoted by the vibration due to earthquake and the like, and prevents abnormal power rise and resultingly improves the integrity and of a reactor by providing a stirring means for coolant in coolant flow path in a fuel assembly. CONSTITUTION:In a fuel assembly for boiling water reactor 15 constituted by bundling a multitude of fuel rods 2 with an upper tie plate 4 locating at the top end, lower tie plate 5 at the bottom end and a plurality of spacers 6 positioned in the middle and containing in a channel box 7, a swirl wane 17 characterized as a stirring means for coolant 8 flowing around the fuel rods 2 is fixed to a lower tieplate in the lower subcool boiling region.