公开(公告)号：US4975241A

公开(公告)日：1990-12-04

申请号：US226109

申请日：1988-07-29

申请人： Karl H. Haslinger ,  Douglas S. Porter ,  Michael L. Martin ,  Woodruff H. Higgins

发明人： Karl H. Haslinger ,  Douglas S. Porter ,  Michael L. Martin ,  Woodruff H. Higgins

IPC分类号： G21C17/10 ,  G21C17/108

CPC分类号： G21C17/108

摘要： A wear-reduction-sleeve for in-core-instrumentation thimbles of a pressurized water nuclear reactor having bottom mounted instrumentation to curtail flow induced excitation and increase support contact area in the region of thimble length which extends through and defines an annulus with the core support plate and extends upwardly to and through the fuel assembly flow distribution plates. The wear-reduction-sleeve includes a hollow shank portion which gives a low wear coefficient when in contact with the chrome-plated thimble and is inserted into the annulus and below where it is radially expanded and secured to a thimble guide tube. An upper portion of the wear-reduction-sleeve between the core support plate and flow distribution plate has a flow collection chamber and radial flow exit slots which divert thimble flow substantially away from the hole in the fuel assembly flow distribution plate through which the thimble extends.