Numerical study on thermal deformation behaviors of the single subassembly in sodium-cooled fast reactors based on Euler-Bernoulli beam theory

•A new method was proposed to simulate thermal deformation of subassembly in SFR.•Assembly deformation analysis code FADAC was developed and applied in the present study.•Free bowing was analyzed under different temperature conditions and displacement field of the subassembly was obtained.•Restrained bowing was analyzed in detail and maximum deflection was calculated.