Design and performance of 2D and 3D-shuffled breed-and-burn cores

Abstract

The primary objective of this work is to find design approaches that will enable 3D fuel shuffling in stationary breed-and-burn (B&B) cores and to quantify the attainable reduction in peak DPA and change in additional performance characteristics going from conventional 2D to 3D fuel shuffling strategies. An additional objective is to establish the tradeoff between the minimum required DPA (displacements per atom) and average required burnup (fuel utilization) for B&B cores spanning a core power range from 1250 to 3500MWth. It is found possible to design a B&B core fuelled with depleted uranium to have a peak radiation damage at or below 350DPA when using 3D-shuffling. Relative to conventional 2D-shuffling, 3D-shuffling offers between 30% and 40% reduction in the peak DPA along with up to 30% increase in the average discharge burnup and, hence, in the depleted uranium utilization as well as significant increase in the core average and specific power density. Per DPA, the 3D shuffling option offers up to 60% higher uranium utilization. Even though 350DPA is above the 200DPA peak radiation damage HT9 steels were exposed to so far, it is below the 400DPA advanced structural materials are expected to tolerate.