The separation of a concrete wall at Progress Energy Inc.'s Crystal River nuclear powerplant in northwest Florida has “fundamentally changed the way the [nuclear power] industry analyzes post-tensioned, pre-stressed concrete structures,” according to the utility’s Oct. 10 filing with the Florida Public Service Commission. The PSC is probing the incident and must approve the North Carolina-based utility's request to have ratepayers cover repair costs.Raleigh-based Progress Energy is seeking to recover expenses related to the delamination of a wall at Crystal River’s nuclear unit No. 3, a problem first identified in October 2009 and again in March 2010 as the company
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.