Thermal Limits

The hot channel factors are computed values employed to take into account different uncertainties in tolerances used in core manufacturing. For instance, consider a coolant channel of the lowest acceptable width and length that occurs to be adjacent to a fuel plate with the highest acceptable fuel loading. In this channel, we now contain less water than in the average channel, receiving more heat than the common coolant channel. For any specified values of core power and flow, this theoretical channel would be closest to a thermal limit. Thus, all design considerations are depending upon the hot channel factor for each core. The nuclear heat flux hot channel feature (HFHCF) is the ratio of the maximum heat flux predictable at any region to the average heat flux for the core. The nuclear enthalpy increase hot channel factor is the ratio of the total kW heat generation all along the fuel rod with the maximum total kW to the total kW of the average fuel rod.

Therefore the limitation of the peak flux value in a core is directly associated to the hot channel factor. Though, in discussing flux profiles, "average" value of flux in the core are generally termed to instead of peaks.