| 摘要 |
PURPOSE:To simplify an equipment and to increase the reliability by providing an outside pipe in which the one end is connected to a gas space between a guard vessel and a nuclear reactor vessel and the other end forms a flow path space between a piping in the reactor vessel chamber. CONSTITUTION:The outside pipes are provided to outsides of pipings 4, 7 respectively and are positioned with holding intervals at outsides of the pipings 4, 7 in the diameter direction so as to form the necessary flow path space between the pipings 4, 7 respectively. The one end of the outside pipe is connected directly or through conducting pipe into a gas space 12 between the guard vessel 3 and the reactor vessel 1. By such constitution, since a preheating gas can be circulated forcedly surrounding the piping, even if the flow in the piping is stopped, the piping temp. can be maintained to cooling medium temp., it is possible to simplify the equipment and to increase the reliability. |
