Validation of the novel core solver nTRACER/COBRA-TF for full core high fidelity cycle analysis of VVERs

This work is focused on the expansion of the Laboratory of Reactor Physics and Thermal-Hydraulics (LRT) of PSI multi-physics high-resolution core solver nTF/CTF to full core cycle analysis for VVERs. The development and code modifications for the nTF/CTF depletion calculation scheme is presented in detail. The 1st cycle of the X2 benchmark is simulated by the novel core solver. All necessary approximations and modeling options to optimize the computational cost of the full cycle calculation are discussed in this work. nTF/CTF is validated on the coarse mesh with experimental data and its high-resolution capabilities for pin and sub-pin predictions are showcased. All discrepancies remain within target accuracy, as it is set by the utilities. The computational requirements for the 1st cycle of X2 are not forbidding for the use of the novel core solver as an auxiliary audit tool for production calculations.