JHR neutron deterministic calculation scheme improvement thanks to Monte Carlo analysis in depletion

Paper i proceeding, 2018

The international Jules Horowitz Material Testing Reactor (JHR) is under construction at CEA Cadarache research center, in southern France. In order to perform JHR design and safety studies, a specific neutron calculation tool, HORUS3D/N, was developed. It is based on APOLLO2 and CRONOS2 deterministic codes and the European nuclear data library JEFF3.1.1. The validation step aims at quantifying the computation tool performances, i.e. the biases and uncertainties associated with HORUS3D/N computations. These biases and uncertainties were in particular assessed by comparing HORUS3D/N deterministic calculations with a reference computation route using a heterogeneous geometry in 2D and 3D. The recent development of the new CEA’s Monte Carlo burn-up code, TRIPOLI-4® version 10, offers the opportunity to study JHR configurations during depletion with a probabilistic computation code. This paper presents, as a complement to the validation step, comparisons performed between HORUS3D/N and TRIPOLI-4® code with its new depletion capability. The study is performed on 2D and 3D computations for different JHR core configurations. It focuses on the reactivity discrepancies as functions of burnup and neutron leakage. Finally, these comparisons will contribute to improve the computation options of the HORUS3D/N calculation scheme. It has been used in order to upgrade the depletion of the boron insert in the reflector and the axial neutron leakage. Improvements consist in an increased number of energy groups (in the homogenized cross section calculations), the removal of transport/diffusion equivalence factors, and a refined geometric modeling.