Development of core thermal hydraulic evaluation methods under natural circulation decay heat removal in sodium-cooled fast reactors; Validation of subchannel CFD analysis using a porous body model

Hamase, Erina ; Kikuchi, Norihiro  ; Doda, Norihiro  ; Tanaka, Masaaki  ; Imai, Yasutomo*

In order to develop numerical analysis that can perform a core-plenum interaction in a commercialized sodium-cooled fast reactor, a subchannel analysis based on a porous body model in CFD code was initially applied to the 37-pin fuel assembly sodium test. As a result of CFD analysis for typical high and low flow conditions, the sodium temperature and the axial velocity at upper heated section in the subassembly were consistent with the ASFRE code that has been validated with experiments data within relative error 1.5%. It was found that a subchannel analysis based on a porous body model in CFD code could apply to the thermal hydraulics analysis in the fuel assembly.