The Research Of The Depressurizing Of Containment During The Severe Accident For The CANDU6 Nuclear Power Plant

Refer to the two CANDU6 units operate by the third Qinshan nuclear power plant,a CANDU6 plant model has been established with an integrated software,which include reactor core,primary process system,safety system,containment and the containment filter venting system.Three scenarios have been selected based on the level 1 PSA result as the severe accident initial events to analyses the containment pressure trend with or without depressurization,with or without filter venting,and the behavior under different pressure set point.The three scenarios are: total loss of Class IV power;large LOCA and feeder bleed stagnation.The analysis indicates that the CANDU6 containment's integrity could be kept under the venting without filtering during the severe accident.The uncontrolled radioactivity releasing will be minimized as well.As to the filtering venting,the radioactivity releasing could be minimized effectively at the same time with the containment integrity be guaranteed,but measures should be adopted in advance in the late period of the severe accident.