Photo Courtesy of MESA Associates The NRC is requiring containment structure for Watt's Bar reactor before licensure. The Tennessee Valley Authority was set to begin pouring the concrete foundation in late August for a 12,000-sq-ft reactor containment structure at its Brown's Ferry nuclear powerplant in Alabama that is being designed to withstand a 10,000-year earthquake and 300-mph winds. Specifications for the building, known as FLEX, were developed by the U.S. Nuclear Regulatory Commission from lessons learned after the 2011 Fukushima accident in Japan."It's an entirely new layer of protection to be used for a beyond-design flood, earthquake or tornado," says
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.