Photo by JA Gonyeau

The containment at some nuclear plants may have a square or rectangular facade so that the true hemispherical design of the containment shell is not visible. This photo shows a plant with a facade. The hemispherical dome in the foreground is actually a secondary shell bolted over the internal containment structure.

The vertical metal pipes seen in the background are the steam relief pipes from the non-radioactive side of steam generators. The safety valves would relieve steam only if pressure exceeded a preset setpoint, usually about 1200 psi.