| 摘要 |
PURPOSE:To improve the heat insulating performance of a heat-insulating apparatus consisting of a heat-insulating metal member surrounding a structure, by attaching a seal member to each of the structure and the heat-insulating metal member, and preventing leakage of hot air by these seal members. CONSTITUTION:In an arrangement in which the outside of a pressure vessel 1 of a nuclear reactor, i.e., a structure to be heat-insulated is surrounded by a cylindrical heat-insulating metal member 2 and a fuel replacing bellows 4 is attached to the outer periphery of a basin seal skirt 3 that is fixed to a flange formed at an upper portion of the pressure vessel 1, a clearance A is formed between the skirt 3 and the heat-insulating member 2 along with temperature rise of the pressure vessel 1. In order to close the clearance A under any circumstances, a steel seal ring 8 having an L-shaped cross section is fixed to the lower surface of the skirt 3 around the outer periphery thereof. Further, a seal ring 9 made of steel plate is fixed to the heat-insulating member 2 so that the seal ring 9 comes into contact with the upper surface of a horizontal section of the seal ring 8 when the skirt 3 is lowered to the position shown by the chain line in the drawing along with temperature drop of the pressure vessel 1. |
