[en] The containment response from an applied load must be resisted by the steel containment. The stresses or strains are random variables Q. The resistance capacity of the steel containment is some distribution of random variables R. Distributions of Q and R are not sufficiently well defined to allow probabilistic design of steel containments. However, the ASME Code places limits on stress which the unfactored load responses must not exceed. Nuclear containments differ from conventional structures in that severe plant mishaps and/or severe natural phenomena form the basis of design and the normal operating loads are dwarfed in comparison. Containment loads can be classified as either normal operation loads, internal events, or external events. Closed form solutions have limited application, so the containment shell is represented by a discretized mathematical model. One-dimensional beam finite elements can be used to model the containment shell under some circumstances. The dynamic response of the above two containment models can be found in the time or frequency domain. Time domain solutions can be found by modal analysis and/or time integration while frequency domain solutions can be found by the Fast Fourier Transform method