Abstract: Using reactor pressure vessel（RPV） bottom junction with core shell as an example,the effect of fabrication dimension error on RPV load-bearing ability is analyzed.The load-bearing ability of the RPV can be evaluated by applying ANSYS and elastic analysis method to carry out stress analysis on RPV bottom junction with core shell and then comparing the stress analysis results and corresponding RCC-M rules.Fol-lowing the above-mentioned procedure,the stress analysis and evaluation on RPV bottom junction with core shell are carried out for 6 cases.In the first case,the dimension of RPV is the same as that given in the design.In other 5 cases,the thickness of the thinnest transition part of the RPV is reduced by 3%,6%,10%,20%,and 30%,respectively.Analysis results indicate that the load-bearing ability of RPV bottom junction with core shell meets the standards of RCC-M rules if the reduction of the thickness does not exceed 30% of its original dimension.