Power Profile Manipulation in Block-Fuel HTGRs

A favorable distribution of fuel temperature in block-fuel HTGRs can be achieved by an axial shift in the power density toward the cooling gas inlet. This is of particular importance for advanced reactor applications requiring gas outlet temperatures above 900°C. The concept of axially graded heavy-metal densities and fuel enrichment allows for achieving and maintaining the desired asymmetrical power profile through the entire period of fuel insertion.