The author of "The Forever Waste" gave too much space to antinuclear types and did not spend enough time researching the underlying facts (C&EN, May 5, page 15). For example, only about 3% of the available fission energy has been extracted from "spent fuel." Obviously, the remaining 97% will be of interest to future generations. In addition, the plutonium made in light-water power reactor fuel (excluding only the outer elements of the initial loading) has far too much of the 238 and 240 isotopes to be usable in a nuclear explosive.
Finally, the standards are being imposed on nuclear wastes that have no inherent danger whatsoever. Bear in mind that uranium and thorium ores have been lying around undergoing decay by -emission and spontaneous fission for a few billion years and are loaded with deadly fission and decay products. If one only requires the final processed waste products to be no more dangerous than pitchblende, then “forever” shrinks to several strontium or cesium half-lives.
Yucca Mountain is one of the U.S.'s driest areas, receiving 7.5 inches of rain yearly, of which 95% evaporates or is transpired by a sparse covering of vegetation. The remainder drains into a water table 500-800 meters below, which is part of the Death Valley hydrogeologic basin. None emerges into streams or lakes. The evidence is that there have been only modest changes in water table level in the past few million years, even in wetter periods. The disposal site is about halfway down, about 350 meters above the water table.
Water seeping past would tend to cling to the tunnel walls rather than contact the waste canisters. A 2004 report of the Nuclear Waste Technical Review Board stated that surrounding conditions made corrosion pitting of the canisters unlikely. Two outgoing members of the Nuclear Regulatory Commission, Jeffrey S. Merrifield and Edward McGaffigan, have stated that they have seen no data to indicate that Yucca Mountain would not be a good place to dispose of spent nuclear fuel.
Contrary to C&EN’s story, no falsification of data has been found in these investigations. What was falsified was quality assurance information about the computer codes used to analyze the data. The analyst didn’t know the dates of origin, revision, and installation of the codes, so he made up the numbers. Then he complained in e-mails to colleagues about the unavailability of the information.
C&EN and Kristin Shrader-Frechette misunderstand the proposed EPA radiation standard for the period between 10,000 and 1 million years. The 350 milliroentgen (mR) per year additional dose limit is calculated for those (if any) living in the desolate land close to the disposal site and drilling for water there. There would be no significant radiation exposure from the disposal site for those farther away. For perspective, the average U.S. natural dose is 300 mR per year, the higher doses being over granitic soils and at higher altitudes.
We should protect future generations from reasonably foreseeable dangers. But protecting 1 million or even 10,000 years into the future from every scenario an armchair theorist can dream up is senseless. In what other important area of life do we use such foresight?
Of course it would be desirable to recycle the uranium and plutonium from the spent fuel rather than bury it, to bury at shallow depth the main heat producers—strontium-90 and cesium-137—and to consume the transplutonium actinides in a fast neutron reactor, all as proposed by the Global Nuclear Energy Partnership. But that is not necessary for the safe use of Yucca Mountain. Nevada’s problem is an image problem, taking something no one else wants, not a safety or environmental problem.
John E. Tanner Jr.
Idaho Falls, Idaho