With reinforced concrete containments with steel liners, the reinforced concrete structure ensures the structural integrity, and the steel liner the gas-tightness. A reinforced concrete containment is about as strong as a pre-stressed concrete one if the stressing steel is replaced with the concrete steel in proportion to their respective yield stresses. With the massive concrete cross-sections usually found in building nuclear power plants, this can be done without further ado.

The steel liner is anchored to the concrete structure via headed studs and/or steel sections so that a steel composite construction exists once it is completed with this concept; but the expansion of the steel liner and stresses on the laminate are less critical, as there is no pre-stressing. The reinforced concrete structure also enables a thicker steel liner to be used. Increasing the inherent rigidity of the steel liner makes it easier to install, and improves its strength and hence its integrity. As with a pre-stressed concrete containment, the design can be based on DIN 25459 [16]. The steel laminate effect must be considered in particular here, especially if using relatively thick steel liners, as with the non-pre-stressed containment of the KERENA BWR reactor model (steel liner t = 10mm).