The U.S. Energy Dept. is headed back to the drawing board for a national nuclear-waste depository. President Barack Obama, making good on a campaign pledge, is seeking an alternate dump site to Nevada’s Yucca Mountain, 90 miles northwest of Las Vegas. “I have consistently said that I am opposed to Yucca Mountain,” Obama told a Las Vegas crowd last January. “That will not change.” Photo: The U.S. DOE The budget at Yucca was cut $100 million for the rest of 2009. The U.S. Energy Dept. has spent over $10 billion since 1983 performing geological tests and studies at Yucca Mountain
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.