Environmental Problems, Their Causes, and Sustainability 1

prevent a fire, but these could malfunction or bedestroyed by a terrorist attack or a deliberate crash bya small airplane. For example, studies in 2002 by theInstitute for Resource and Security Studies and theFederation of American Scientists estimated that releaseof all radioactive material in the spent-fuel rodsin the storage pool at the Millstone Unit 3 reactor inConnecticut because of an accident or terrorist attackwould put five times more radioactive material intothe atmosphere than the 1986 Chernobyl accident.And an area larger than New York state would be uninhabitablefor at least 30 years because of radioactivecontamination.According to these studies, about 161 million people—57%of the U.S. population—live within 121 kilometers(75 miles) of an aboveground spent-fuel site.There are 127 such sites in 44 states, mostly in the easternhalf of the country (Figure 17-25).U.S. nuclear power officials consider such eventsto be highly unlikely worst-case scenarios and questionsome of the estimates. They also contend that nuclearpower facilities are safe from attack. Critics arenot convinced and call for constructing much more securestructures to protect spent-fuel storage sites. Theyaccuse the NRC of failure to require this because itwould impose additional costs on utility companies,raise the cost of nuclear power, and make it a less attractiveenergy alternative.What Do We Do with Low-Level RadioactiveWaste? Dump It in the Ocean, Bury It inSpecial Landfills, or Mix It with OrdinaryTrashThe nuclear fuel cycle and other nuclear facilityprocesses produce low-level radioactive wastes thatmust be stored safely for 100–500 years before theydecay to safe levels.Each part of the nuclear fuel cycle (Figure 17-24) produceslow-level and high-level solid, liquid, andgaseous radioactive wastes with various half-lives(Table 3-1, p. 49). Wastes classified as low-level radioactivewastes give off small amounts of ionizing radiationand must be stored safely for 100–500 years before decayingto safe levels. Such wastes include tools, buildingmaterials, clothing, glassware, and other items thathave been contaminated by radioactivity.From the 1940s to 1970, most low-level radioactivewaste produced in the United States and most othercountries was put into steel drums and dumped intothe ocean; the United Kingdom and Pakistan still disposeof them this way.Today, low-level waste materials from commercialnuclear power plants, hospitals, universities, industries,and other producers in the United States are putin steel drums and shipped to the two regional landfillsrun by federal and state governments. Attempts tobuild new regional dumps for low-level radioactivewaste using improved technology have met with fiercepublic opposition.To lower costs, nuclear industry and utility officialshave been lobbying Congress and the NRC todeclare such waste safe enough to be mixed with ordinarytrash and deposited in conventional landfills.What Should We Do with High-LevelRadioactive Waste? A Dangerous and Long-Lasting Unintended ConsequenceThere is disagreement among scientists over methodsfor the long-term storage of high-level radioactivewaste.After more than 50 years of research, scientists still donot agree on whether there is a safe method for storinghigh-level radioactive waste. Some believe the longtermsafe storage or disposal of high-level radioactivewastes is technically possible. Others disagree, pointingout that it is impossible to demonstrate that anymethod will work for 10,000–240,000 years.Here are some of the proposed methods and theirpossible drawbacks.Bury it deep underground. This favored strategy isunder study by all countries producing nuclear waste.In 2001, the U.S. National Academy of Sciences concludedthat the geologic repository option is the onlyscientifically credible long-term solution for safely isolatingsuch wastes. However, according to an earlier1990 report by the U.S. National Academy of Sciences,“Use of geological information to pretend to be able tomake very accurate predictions of long-term site behavioris scientifically unsound.”Shoot it into space or into the sun. Costs would bevery high, and a launch accident—like the explosion ofthe space shuttle Challenger—could disperse high-levelradioactive wastes over large areas of the earth’s surface.This strategy has been abandoned for now.Bury it under the Antarctic ice sheet or the Greenlandice cap. The long-term stability of the ice sheets is notknown. They could be destabilized by heat from thewastes, and retrieving the wastes would be difficult orimpossible if the method failed. This strategy is prohibitedby international law.Dump it into descending subduction zones in the deepocean (Figure 16-5, middle, p. 336). But wastes eventuallymight be spewed out somewhere else by volcanicactivity, and containers might leak and contaminatethe ocean before being carried downward. Also, retrievalwould be impossible if the method did notwork. This strategy is prohibited by international law.Bury it in thick deposits of mud on the deep-ocean floorin areas that tests show have been geologically stable for 65million years. The waste containers eventually would372 CHAPTER 17 Nonrenewable Energy Resources