Universal SPICE model for submicron SOI/SOS MOSFETs based on BSIMSOI and EKV-SOI platforms with account for total ionizing dose-induced effects (TID), pulsed radiation effects, single events is presented. A special subcircuit consisting of parasitic transistors for sidewall and backgate leakage currents and other elements is connected to the standard SPICE model. In addition, the radiation-dependent parameters are described by physically based mathematical equations. Model parameter extraction methodology is described. Examples of radhard SOI/SOS CMOS circuits simulation are presented.