Background: Several aspects will influence the weld residual stress analysis of CRDM penetration

such as formation and distribution of heat source

heating and cooling processing

finite elements meshing

phase changing

etc.Purpose: Develop an effective method for weld residual stress analysis

research the influence of interval between heating and cooling step during multipass beads procedure.Methods: Finite elements with a sequentially coupled approach are applied

including a transient thermal analysis simulating the heating and coduring and their interval between multipass welding.Results: An appropriate finite method is developed for weld residual stress simulation.Conclusions: Apropriate interval time must be choosed between multipass weld beads to avoid poor weld residual stress

and contact pressure between RPV shell and CRDM adapter tube also should be check for strcture integrity.