Computational Analysis of Environment Condition Inside Containment under Severe Accident

Considering the detail requirements of evolutionary and advanced light-water reactor design and taking the mitigation measures for severe accidents in Chashma Nuclear Power Plant（NPP） Unit-2 as an example,this paper analyzed the severe accident sequences affecting the environment conditions inside containment such as the large LOCA with safety injection failure,small LOCA with safety injection failure and Station Blackout with AFW failure,and its mitigation measures..The results show that the containment pressure and temperature are decreased obviously after the containment spray is recovered.As a result,the environment condition inside containment comes to available for the equipment.