| 摘要 |
<p>A fixing device for nuclear reactor fuel rods consists of a rod holding plate with holes for the end portions of the rods. Each end portion of a rod comprises, longitudinally in succession: an abutment surface (stepped-in shoulder), an annular groove of width greater than the depth of the holding plate, a shoulder (stepped-out shoulder) and an associated bulge or thickening of diameter larger than the hole through the plate; the end portion is also split by axial slits extending from the bottom tip at least as far as the annular groove, and the resultant 'fingers' between the slits are of elastic material. Thus, when the end portion is pushed through the plate, the fingers spring out and engage by the stepped-out shoulder and bulge against the lower face of the plate. Means for bringing the fingers together, to release this snap-fit are provided, esp. a coaxial ring, tube etc. on a releasing plate, which is raised and pushed axially onto the external faces of the fingers, so that mutual tapering of the ring and fingers closes the fingers and permits withdrawal of the fuel rod. The fuel rods can be reliably and easily engaged in the holding plate and easily released from it.</p> |
