Sub compartment pressurization analysis for auxiliary building of APR1400DC

Generally, the sub compartment of PWR means a fully or partially enclosed volume that could house high-energy piping systems or restrict the flow of fluid in the event of a postulated pipe rupture. To meet the requirements of General Design Criteria (GDC) 4 and 50, Standard Review Plan (SRP) 6.2.1.2 states that the sub compartments shall be designed with sufficient margin to prevent the fracture of structure due to pressure differential across the walls of the sub- compartment and specifies the criteria related to the design and functional sub compartment nodalization schemes, vent flow path and vent flow behavior. Therefore the sub compartments structures within the containment and auxiliary building are designed to withstand the transient differential pressures loads, jet impingement forces, and pipe whip forces occurring due to a postulated pipe break. In this paper, the analyses of pressure transients after a postulated pipe rupture in sub compartments of APR1400DC auxiliary building is performed and the calculated peak differential pressures during the piping break transients for each sub compartment are less than structural design differential pressures