| 摘要 |
PURPOSE:To obviate the leakage of water to a reactor pressure vessel even if there is leakage from a valve by providing a connecting piping which is opened at one end and is connected at the other end to the upper stream side of a circulation pump between a 1st stop valve of a head spray and a 2nd stop valve of the head spray. CONSTITUTION:The connecting piping 17 which is opened at one end and is connected at the other end to the upper stream side of the circulation pump is provided between the 1st stop valve 11 of the head spray and the 2nd stop valve 12 of the head spray. The pressure on the upper stream side of the stop valve 11 is the pressure obtd. by adding the pressure of the pump 6 to the reactor pressure and subtracting the pressure loss of the piping therefrom. The pressure between the stop valve 11 and the stop valve 12 is the pressure after the pressure of the suction piping is subtracted from the reactor pressure. This pressure is slightly lower than the reactor pressure. The pressure on the down stream side of the stop valve 12 is the reactor pressure. The pressure between the stop valve 11 and the stop valve 12 is then the min. pressure. The leakage of the water to the reactor pressure vessel 1 is thereby obviated even if there is the leakage from the valve 12. |
