For the research on the safety limit of nuclear power plant containment under extreme conditions (i.e. being subjected to earthquake and internal pressure simultaneously)

a detailed three-dimensional finite element model for containment of CPR1000 was established. Considering the nonlinear properties of materials

the acceleration

displacement and strain responses of nuclear containment under seismic load

internal pressure and combination of them were simulated by ABAQUS software. As the result has shown: 1)When the concrete cracking area of the containment penetrates the inner and outer layers

the nuclear leaks may occur

which is regarded as the safety limit of the containment. So when the internal pressure is applied only

the anti-pressure safety limit of the containment is 120 kPa. 2)Comparing with the containment under the seismic load of 0.2 g simultaneously

the safety limit becomes 100 kPa

which decreases by 16.7%. 3)Likewise

the seismic safety limit of containment is 0.4 g when there is only seismic load. But when it is subjected to internal pressure of 50 kPa

limit downs to 0.3g

which is reduced by 25 %. 3)In addition

the acceleration and displacement responses of the containment have no much change under the simultaneous load of the internal pressure below 100 kPa and the earthquake below 0.4 g

comparing with applying them respectively.