For evaluating damage of strong explosion,boundary conditions of coupled Eulerian-Lagrangian calculation are used.Energy accumulation due to radiative transfer is considered.Coupled methods of two-dimensional numerical simulation with cylinder symmetry are established,which calculate simultaneously equations of radiation hydrodynamics and hydro-elasto-plastic.Full physical processes of underground strong explosion are presented.They are propagation of radiation front in detonating room,transmitting of radiative energy to wall of detonating room,inward expanding of detonating room wall,propagation of shock wave in rock,compressing of high-pressure in detonating to room wall and outward expanding like waves of detonating room wall.

With Fokker-Plank equation of pitch-angle diffusion,a numerical method for atmospheric diffusion loss of radiation belt trapped electrons is shown.Flux and energy spectrum are calculated as atmospheric scattering of fission β spectrum electrons injected in radiation belt by high altitude nuclear detonation.Diffusion due to atmospheric scattering is remarkable as L < 1.3.Low energy electrons are removed more rapidly than those with high energy.Electron flux decays rapidly at an initial phase and then decays gradually as an exponential function of time.

One-dimensional radiation hydrodynamics equations with spherical symmetry are used to study early development of fireball front and case shocks in strong explosion.Numerical method for radiation transport equations is established.The calculation results agree well with Brode's.Early formation of fireball front and case shocks in strong explosion at different yield,density in explosion zone and altitude are simulated numerically.Calculation results are analyzed.