In this paper

the Damping Solvent Extraction Method（DSEM）in the finite element framework is proposed to consider the influence of infinite foundation radiation damping and the coupling of the nuclear power plant and the infinite foundation substructure is realized by combining the interaction force balance mechanism and displacement coordination.As a result

a time domain model for the seismic analysis of the foundation of the nuclear power plant is established.In order to improve its practicability

the two development tools UPFs

APDL and UIDL are used to achieve the DSEM key technologies.Through analysis of process control and visual operation the developed model is embedded in the general finite element software ANSYS.And then

the effect of different frequency harmonic waves on the accuracy and efficiency are analysed by the numerical example.The suitable parameter range of engineering application is sugested.Finally

the seismic adaptability analysis of the foundation of a million kilowatt pressurized water reactor is carried out.The results show high reliability and practicability.