Demolition of one 102,000-sq-ft facility amid many others on the 586-sq-mile Hanford nuclear waste site may seem minuscule, but not when the facility contains some of the world’s highest radiation levels. Photo: Washington Closure Hanford Work to demolish large and highly radioactive research cells is soon to start. Washington Closure Hanford, a joint-venture cleanup contractor at the U.S. Energy Dept.’s former weapons-making site in eastern Washington, and a subcontracting team will soon remove five massive steel-reinforced concrete “hot cells.” While no longer in use, they previously allowed site employees to work with nuclear materials without radiation exposure. Removal of the
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.