JP2505808B

PURPOSE:To prevent the vibration of a cooling water check valve and the fluctuation in the speed of a control rod driving mechanism by providing a check valve with a vibration absorbing mechanism and orifice for adjusting the flow rate of cooling water to the cooling water check valve. CONSTITUTION:The check valve 38 with the vibration absorbing mechanism consists of a valve body 38A, a check ball 38B, a vibration absorbing gage 38D, and a vibration absorbing body 38E and is provided with the orifice 40 as a mechanism for controlling the flow rate of the cooling water at the bottom end of the gage 38D. Since the vibration absorbing mechanism of the check ball 38B is provided to the check valve 38 in such a manner, the vibration and abnormal noise of the check ball 38B are immediately controlled even if said vibration and noise are generated. In addition, the fluctuation in the speed of the control rod driving mechanism is prevented.