Environmental Problems, Their Causes, and Sustainability 1

corrode and release their radioactive contents. This approachis prohibited by international law.Change it into harmless, or less harmful, isotopes. Currentlyno way exists to do this. Scientists are investigatingthe use of a linear accelerator to speed up thenormal rates of radioactive decay. But even if this orother methods are developed, costs would probably bevery high, and the resulting toxic materials and lowlevel(but very long-lived) radioactive wastes wouldstill need to be disposed of safely.Case Study: The Yucca Mountain StorageSite for High-Level Radioactive Wastes—Controversy over Desert BurialScientists disagree over the decision to storehigh-level nuclear wastes at an underground storagesite in Nevada.In 1985, the U.S. Department of Energy (DOE) announcedplans to build a repository for undergroundstorage of high-level radioactive wastes from commercialnuclear reactors and some nuclear weapons facilities.The site is to be built on federal land in the YuccaMountain desert region, 160 kilometers (100 miles)northwest of Las Vegas, Nevada (Figure 17-25).The proposed facility (Figure 17-28) is expected tocost at least $58 billion to build (financed partly by atax on nuclear power). It is scheduled to open by 2010and begin taking in high-level radioactive waste nowstored at 127 sites in 44 states. But officials concedethat it is not likely to open until 2015. After the site isfilled with waste it is supposed to be monitored for 300years and then sealedThe wastes are to be buried in tunnels deep belowthe surface of the almost 1,500-meter- (5,000-foot-)high mountain and well above the current water table.They will be inside containers made of a special metalalloy designed to withstand the high temperatures ofthe radioactive waste and covered with a shield to protectthe metal from corrosion by dripping water.Currently, the area gets only 15 centimeters (6inches) of rainfall per year and most of this evaporatesin the desert heat before it can seep underground. Butno one knows whether the climate of this area will getwetter over the next 10,000 to 240,000 years.A number of scientists and energy analysts haveserious concerns about the safety of this site. For one,they are concerned that rock fractures and tiny cracksmay allow water to leak into the site and eventuallycorrode casks holding radioactive waste. DOE computermodels said that water would not flow into thesite, but a scientist found evidence that at one time waterhad flowed deep into the mountain through tinycracks in a matter of decades. In 1998, Jerry Szymanski,formerly the DOE’s top geologist at Yucca Mountainand now an outspoken opponent of the site, said that ifwater flooded the site it could cause an explosion solarge that “Chernobyl would be small potatoes.”Storage ContainersFuel rodGround LevelUnloaded from trainPersonnel elevator2,500 ft.(760 m)deepPrimary canisterOverpack containersealedAir shaftNuclear waste shaftUndergroundLowered down shaftBuried and cappedFigure 17-28 Solutions: general design for deep underground permanent storage of high-level radioactivewastes from commercial nuclear power plants in the United States. (U.S. Department of Energy)http://biology.brookscole.com/miller14373