Effectiveness of containment depressurization spray system in nuclear reactors

In a PWR nuclear power plant, the containment spray system forms the last protection barrier that guards againstthe release of radioactlvity to the atmosphere in case of an accidental rupture of the reactor coolant pressure boundary or a steam line break. If such an accident takes place, the containment spray system is called upon to act in order to reduce the pressure build up inside the containmentstructure and thus maintains the containmenr pressure within the permissible limits.The direct contact condensationspray DROPlets and the water / steamcontainment forms the basic designcontainment spray system.Most of previous work in this area has been carried out neglecting the effect of the change in DROPlet size andmass ,which may affect the acting forces on the DROPlets through its journey in the containment atmosphere such as drag and gravitational forces .Therefore, through the present workthe change in DROPlet diameter and mass is taken into consideratlon as