Cross-verification of SUHAM-TD and nTracer reactivity insertion transient solutions without materials homogenization approximation using OECD/NEA C5G7-TD benchmark

Abstract

Recent advances in the development of methods and tools for enhanced accuracy reactor simulations have allowed moving towards time-dependent neutron transport solution without spatial cross-sections homogenization approximation. Although the full core reactor dynamic problems are still too much challenging for the modern codes, reduced order problems can be solved already today. Examples of the codes allowing such advanced transient calculations are, among several others, the SUHAM-TD and nTracer codes, which are discussed in this work. In order to perform an intermediate verification of the SUHAM-TD code, which is under development at the Kurchatov Institute, and to perform an independent verification of the nTracer code of the Seoul National University by its user team at the Paul Scherrer Institute, performances of these two codes have been assessed using the ongoing OECD/NEA C5G7-TD Phase-I benchmark exercises. In particular, two cases of positive reactivity insertion were selected for detailed comparison, being the most relevant from the point of view of future practical applications.