RECENT PROGRESS IN THE VV OF THE NEW CEA APOLLO3~® CODE : ADVANCED SFR/LWR ASSEMBLY CALCULATIONS

摘要

This paper presents the latest advances of the Verification&Validation works achieved within the framework of the new CEA APOLLO3~® code project. It focusses on the performances of the brand new SFR and LWR assembly calculation routes (representative of ASTRID or EPR cores). Based on the most recent development of the TDT-MOC flux solver and self-shielding model (using sub-group and exact/multicell P_(ij) methods) 1968 groups cell and assembly calculation are validated against Monte-Carlo TRIPOLI4~® continuous-energy calculations. This V&V work highlights the ability of the new relevant functionalities implemented in APOLLO3~® to deal with unstructured SFR or LWR geometries leading to high precision results (generally less than 100 pcm reactivity worths and few percents regarding reaction rates errors) and less approximates compared to the previous code generation (APOLLO2 or ECCO-ERANOS system codes). On the other hand it is also pointed out that the implementation of simplified methods such as P_(ij) multicell or P_(ij) with current-interface method or advanced heterogenous leakage model development has to be finalized to fasten project calculations or deal precisely with important leakage streaming effects.