Description and preliminary results of PHENIX core flowering test

Method of Characteristics for 3D, Full-Core Neutron Transport on Unstructured Mesh

“…One of the primary drivers for this is the need to be agnostic to model complex, heterogeneous axial geometry. In addition, multiphysics effects, such as core "flowering" in sodium-cooled fast reactors, 8 can also be captured using flexible 3D neutron transport tools. Unfortunately, highfidelity, 3D neutron transport calculation has largely remained on the sidelines due to large computational requirements.…”

Monte Carlo Neutronics and Thermal-hydraulics coupling applied to Fast Reactors

“…An example of thermomechanical code is the fine element program ANSYS. This effect is fundamental in fast reactor where the high temperature gradient between core top and bottom makes the core to adopt an special shape known as flowering [23]. Changes of reactor dimensions have an impact on reactivity because the mean free path in FR is high.…”

“…Due to the key importance of the expansion reactivity coefficient in some fast reactors transients, several experiments have been carried out to estimate the reactivity effect of the expansion as well as to validate the computational tools. The reactivity feedback induced by core flowering have been experimentally studied in mock-up critical cores [114] and in an industrial reactor with an authentically irradiated core in the PHENIX end-of-life tests [23]. In all these experiments the main difficulty to reproduce experimental results was in the representation of the real geometry of the system by the computer codes.…”