AREVA NP's industrial CFD single-phase methodology and applications for nuclear fuel

摘要

During the course of the last decade, AREVA NP has developed Computational Fluid Dynamics (CFD) methods capable of accurately predicting flow fields and thermal mixing within fuel bundles, as well as pressure losses and hydrodynamic forces on fuel assembly components such as spacer grids, lower and upper nozzles. The present work summarizes the evolution of AREVA NP's single-phase CFD methodology and the extensive validation efforts, with focus on improving confidence level in CFD results. Currently, it is possible to produce models for large sections of a fuel assembly and produce CFD simulation results with an uncertainty proven to be similar to the corresponding measurement uncertainty Extensive validation has been conducted against in-house data obtained for a wide range of geometries representative of actual hardware, in multiple test facilities, with various measurement techniques. In addition to in-house validation data, AREVA NP has also exercised its best-practices against international benchmarks, blind test results were in very good agreement with the data The current high level of confidence in single-phase CFD predictions allows investigating a wide variety of physics in Pressurized Water Reactor (PWR) as well as Boiling Water Reactor (BWR) fuel assemblies CFD is used as a design and optimization tool as well as a supplement to regular testing to improve the quality of tests and optimize hardware design features for specific targets CFD played a major role in the design of AREVA NP's latest fuel assembly designs (ATRIUM~(™) 11 and GAIA) In this paper we first illustrate AREVA NP's comprehensive validation database for single-phase CFD (pressure drop, flow field), then provide several examples of applications' virtual testing for parts optimization and support of core operation