This chapter provides a summary of analysis and design and pre-operational inspection and testing requirements for concrete and steel containments. Both conventionally reinforced as well as prestressed concrete containments are included. Containments are intended to provide a leak-tight boundary against accident pressure loading which essentially dictates the generally used cylindrical shape. The size of the containment and available free volume depends upon equipment layout and operational requirements. The available free volume within the containment affects the magnitude of pressure that can be generated during an accident. In general, conventionally reinforced concrete and steel containments have been used for small containments with low to moderate internal design pressure. But large containments with relatively high internal design pressure require either a prestressed concrete or a steel containment. In general, selection of containment type (conventional concrete, prestressed concrete or steel) depends upon considerations for the equipment size and layout, design pressure and other loadings, construction cost and schedule.