Patent Number: 046648798
Section: abstract

A guide tube flow restrictor for use on an upper guide tube housing support plate of a nuclear reactor, for guiding of a control rod drive shaft through an aperture in the support plate and restriction of flow of coolant therethrough, has an outer ring seatable on the support plate, the outer ring having a flange member from which there depends a plurality of flexible members, the flexible members having inwardly disposed deflectors thereon, and extending through the bore of the outer ring and the aperture of the support plate. An axially insertable sleeve, upon insertion into the outer ring, between the flexible members, contacts the deflectors thereon to radially force the flexible members outwardly to secure the same with the walls of the aperture of the support plate. Baffles are provided on the flexible segments and additional locking members provided between the outer ring and inner sleeve. Shoulders on the outer ring prevent the accumulation of deposits or corrosive affects which could render difficult the disengagement of the outer ring and inner sleeve for replacement thereof.