Merit Index for Gas-Cooled Reactor Heat Transfer

A simple merit index has been derived to compare potential improvements in gas-cooled nuclear reactor cores, such as artificial surface roughening of the fuel rods. For given pumping-to-thermal power ratio, the core output per unit heat transfer area is proportional to the merit index (N³/ƒ)^1/2. Stanton number, or dimensionless surface heat transfer coefficient, is N_s, and f is the friction factor.