Pressurized water-cooled nuclear reactor (PWR) core has each fuel assembly supporting cage in form of rigid structure of end units and lengthwise members

摘要

A PWR core has a series of fuel assemblies (5) between top (8) and bottom (7) plates, each in a supporting cage (5a) in the form of a strong, rigid structure (21) made up of top (17) and bottom (16) end units and rigid lengthwise connecting members (22). Each assembly has a total length that is less than the vertical distance between the top and bottom plates, so that permanent contact between the upper unit of the assembly and the top plate is avoided by having a clearance of between 2 and 10 mm.