Stability performance of steel liner domes of nuclear reactor containment during construction

The steel liner dome of containment structures has a large span and small thickness, and is attached to the concrete with welded studs and angle steel section anchorages. It acts as the interior formwork during pouring of the concrete, but there is no support or brace for the steel liner dome owing to the construction difficulty, which makes the issue of stability during construction very important. A pressurized water reactor containment was used as an example to investigate the stability of a steel liner dome during construction. In the first key construction phase, stability analysis of the steel liner dome was carried out systematically to obtain the buckling modes and plasticity development. The effect of initial geometrical imperfections on the stability of the steel liner dome was investigated, and a prediction equation for the stability bearing capacity was proposed. In the second key construction phase, the functional failure of the steel liner–concrete composite dome was investigated, and the effects on the buckling loads of composite domes were examined. The results show that the transition area of the dome at which the radius of curvature changes is the weak area in the first key construction phase. Dents occur at this transition area, and the plasticity development at the transition area results in the buckling of the whole structure. The effect of initial geometrical imperfections on the ultimate bearing capacity is not significant. The functional failure is cracking in the ring beam during the second key construction phase.