| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel assembly, having a structure for preventing a fuel rod from vibrating due to a cooling material injected from a hole, when the inner surface of a control rod guide thimble is worn by the vibration of a control rod and perforated with the hole, preventing insertability of a control and cluster into the thimble from lowering, and reinforcing decrease in the strength due to wear of the thimble. SOLUTION: The fuel assembly for a nuclear reactor comprises a thin tubular sleeve 21 having a thickness of 1 mm or smaller, arranged on the outer periphery of the control rod guide thimble 4 between a first support lattice 3a nearest an upper nozzle 1 and a second support lattice 3b secondly nearest the nozzle 1 of a support lattice 3. That is, the sleeve 21 is disposed so as to cover a lower end 71 of the rod 16, inserted into the thimble 4 from the outside of the thimble 4 at a core operating time of the reactor. The material of the sleeve 21 is a zirconium-based alloy and is fixed to the thimble 4 at both ends by bulging machining. COPYRIGHT: (C)2003,JPO
|
