Patent Number: 
Section: claims

1. A feed water pipe for a steam generator comprising:a generator internal pipe section that extends in the horizontal direction inside a steam generator and includes a pipe path through which cooling water supplied from the outside of the steam generator circulates;a communication pipe section that is connected to the generator internal pipe section and is provided with a communication path which allows communication between the pipe path and a space outside the generator internal pipe section inside the steam generator;an insertion pipe section that is inserted into a penetration hole penetrating an outer shell member of the steam generator and that extends in a horizontal direction; anda connection pipe section that is provided between the insertion pipe section and the generator internal pipe section, the connection pipe section being bent with respect to the insertion pipe section so as to raise the generator internal pipe section and introducing the cooling water supplied from the outside from the insertion pipe section to the pipe path,wherein one end of the communication path is connected to the pipe path at an upper end of a cross-section perpendicular to a flow direction of the cooling water in the pipe path and another end of the communication path is positioned lower than the one end of the communication path in a vertical direction, andwherein the upper end of the cross-section perpendicular to the flow direction of the cooling water of the pipe path is positioned upper than an upper end of an inner wall surface of the insertion pipe section in the vertical direction. 2. The feed water pipe according to claim 1,wherein the another end of the communication path is positioned at or lower than a position of a lower end of the generator internal pipe section in the vertical direction. 3. The feed water pipe according to claim 1,wherein the another end of the communication path is positioned lower than a target water level of the cooling water in the exterior space in the vertical direction. 4. The feed water pipe according to claim 1,wherein the another end of the communication path is positioned lower than the upper end of the inner wall surface of the insertion pipe section in the vertical direction. 5. The feed water pipe according to claim 1,wherein a lower end of the pipe path is positioned upper than the upper end of the inner wall surface of the insertion pipe section in the vertical direction.