| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an assembly method of a fuel assembly and an assembly structure of a fuel assembly, suppressing occurrence of residual stress in a control rod guide thimble so that a fuel assembly having high straightness with small distortion and inclination can be easily manufactured. <P>SOLUTION: An assembly method of a fuel assembly comprises the steps of: screwing a lower screw forward in the upward direction so that the lower end of a control rod guide thimble is connected to a lower nozzle; and screwing an upper screw having a reverse thread to the lower screw forward in the downward direction so that the upper end of the control rod guide thimble is connected to an upper nozzle. An assembly structure of a fuel assembly comprises: an upper screw and a lower screw having a reverse thread relation therebetween; a lower thread part arranged at the lower end of a control rod guide thimble; and an upper thread part having a reverse thread to the lower thread part, which is arranged at the upper end of the control rod guide thimble. The lower end of the control rod guide thimble is screw fastened to the lower nozzle, and the upper end of the control rod guide thimble is screw fastened to the upper nozzle. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
