Heat Loss Analysis of a Re-entrant Fuel Channel for SCWR Type Reactors

Abstract

One of the fuel-channel design concepts for a Pressure Tube (PT) SuperCritical Water-cooled Reactor (SCWR) currently under development is called the re-entrant fuel channel. The re- entrant fuel-channel design consists of two tubes, the inner tube (flow tube) and the pressure tube. The fuel bundles are placed in the inner tube. The flow and pressure tubes form an annulus through which flows the primary coolant. The coolant flows through the annulus receiving heat from the inner tube from one end of the channel to the other. At the far end, the flow will reverse direction and enter the inner tube, and hence the fuel bundle-string. The results from a numerical analysis performed using MATLAB indicate that the total heat loss from the re-entrant channel will be too high when no insulating barrier is included in the design. Thus, the design of the re-entrant fuel channel needs an insulating barrier for normal operating conditions.