Performance of Woodcock delta-tracking in lattice physics applications using the Serpent Monte Carlo reactor physics burnup calculation code

This paper presents the delta-tracking based geometry routine used in the Serpent Monte Carlo reactor physics burnup calculation code. The method is considered a fast and efficient alternative to the conventional surface-to-surface ray-tracing, and well suited to the lattice physics applications for which the code is mainly intended. The advantages and limitations of the routine are discussed and the applicability put to test in four example cases. It is concluded that the method performs well in LWR lattice applications, but really shows its efficiency when modeling HTGR particle fuels.