cycle and of reactors; the possibility and effects of major nuclear accidents; the handling of radioactive wastes; and the production of nuclear bombs by nations or subnational groups using fissile materials obtained from nuclear-powered facilities.
At all stages of the nuclear fuel cycle, some radioactivity is released to the environment. The largest burden from these releases has come from the underground mining of uranium and from the milling process by which uranium is concentrated from its ores. The hazards of uranium mining have been estimated as resulting in about 15 deaths per year per 10,000 miners. The radioactivity in the mine increases the hazard of cancer, although the risk of accidental fatality in mining accidents is higher than the increased cancer risk.11 Per miner-year, the hazards of uranium mining are comparable to those of coal mining, but because the same energy is recoverable from only about 1 percent as much material, the mortality of uranium mining is, per unit of power, far less serious than that of coal mining. (See chapter 9.)
Additional radioactive emissions come from the mill tailings—the residues from the uranium concentration process—which contain over 80 percent of the ore’s original radioactivity. Past practices have been careless, resulting in exposure of the tailings to weathering, which releases some of the radioactivity to the environment, and in their incorporation into concrete and landfill for homes and schools, in extreme cases. Although the total morbidity from such handling has been quite small, these consequences have cast doubt on the seriousness with which the industry and the responsible federal agencies approach the job of protecting the public.*
Other routine sources of emission are the releases permitted from nuclear power plants (within set limits) of materials that have become radioactive, and potential releases of radioactive gases (such as krypton-85 (85Kr), tritium, and carbon-14 dioxide) from reprocessing plants.
All these “normal” or routine releases of radioactivity are estimated to increase environmental radiation by a small fraction of the existing background, and on this basis, their effects per unit of power generated are small compared to the mining risks, or to the risks of other energy sources.†
More controversial is the possibility of reactor accidents. Much of the controversy has focused on the validity of risk assessments made in the Reactor Safety Study for the Nuclear Regulatory Commission (also known as the Rasmussen Report or WASH-1400). This report attempted to