| 摘要 |
PURPOSE:To relieve an impact load arising on each member upon scram of a control rod driving mechanism by providing a tapered zone on several spots of a buffer shaft in a buffer suitable for the control rod driving mechanism of an nuclear reactor. CONSTITUTION:A buffer is equipped with an index tube 9, the interior of which is arranged with a stop pin 10, buffer shaft 21, and a buffer piston 13 interposed between the stop pin 10 and the buffer shaft 21. The buffer piston 13 is depressed by a spring 14, stopped in a concavity 9a of the tube 9 at its bottom and thus interlocked with the tube 9. There is then provided a tapered zone 17 trending downward on the shaft center side circumferentially on a plural spot of a periphery of the buffer shaft 21, thereby allowing water in a void 16 pressurized at scram to flow downward. |
