Variable axial power profile heat-loss analysis of a co2 gas insulated re-entrant SCWR fuel-channel

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 (REC). The current reference re-entrant fuel-channel design consists of three tubes, the inner tube (flow tube), pressure tube and an outer calandria tube. The fuel bundles are placed in the inner tube. An annulus is formed between the flow and pressure tubes, through which the coolant flows. 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. Carbon dioxide gas is used as an insulator in the gap in-between the pressure tube and the outer calandria tube. The objective of this work is to model the heat loss to the moderator for the REC design using a variable axial power profile.