Core support plate - with cooling fluid passages provided with flow restrictors to produce laminar flow in the fuel assemblies

摘要

A core support structure for fuel assemblies in the core of a reactor, fixed to the lower end of a core sleeve enclosing the core and suspended in the reactor vessel, consists of a simple plate provided with a series of channels for the passage of the cooling fluid, extending vertically through it at each fuel assembly support location. Each of the channels has a throttling orifice at its inlet and a zone of greater diameter downstream of this orifice, such that the cooling fluid penetrating the channels experiences a pressure drop and the flow of the fluid leaving the channels is laminar so as to ensure a uniform flow distribution of the cooling fluid in the interior of the fuel assemblies constituting the reactor core. Simplifies the core support construction very considerably so that the number of assembly operations and the cost is substantially reduced.