Numerical Modelling of the No-Core-Melt Passive Safety Feature in the Generation IV Canadian SCWR

Heat transfer through a typical fuel channel in a Generation IV Canadian Supercritical Water Reactor was modelled numerically using Finite Element Method software. With the objective of limiting the fuel cladding to sub-melting temperatures during a Loss of Coolant Accident, it was found that two distinct fuel channel designs both attained maximum cladding surface temperatures of T = 1,120 C; a result that compared favourably with the 1,450 C melting point of the stainless steel cladding. However, given the similar temperatures yielded by the reference and alternate fuel channel designs, it was deemed necessary to devise another metric for identifying the better performing variant. In this vein, the ratios of LOCA to normal operation thermal fluxes were computed and it was observed that the reference configuration performed best by limiting losses in normal operation while also permitting sufficient heat rejection to the moderator during the LOCA.