Science in Christian Perspective
Far Greater Dangers than
Bernard L. Cohen
Department of Physics and Astronomy,
University of Pittsburgh,
Pittsburgh, Pennsylvania 15260.
From: JASA 32
The paper on "Nuclear Wastes" by Ellen Winchester proves only one thing, that nuclear energy is not "perfectly safe." However, that is not a practically useful conclusion, because no method for generating electricity is perfectly safe-coal and oil burning cause lethal air pollution, gas kills by asphyxiation and explosions, hydroelectric dam failures could drown hundreds of thousands in a few minutes, solar energy requires vast quantities of steel, aluminum, and cement whose production causes a wide variety of deadly pollution problems and doing without electricity would be many times more dangerous than any of them. If the purpose is to show that we should not use nuclear energy because of the radioactive waste problem, then it must he shown quantitatively that these wastes do more harm to human health than the alternatives.
Dangers of Coal
I will therefore do what she has failed to do, to quantify the dangers of nuclear waste, and to compare them with the dangers of obtaining the same electricity from burning coal which is our only presently viable alternative. Typical estimates are that the wastes from coal burning, must of which are simply discharged into the air (air pollution) are at least 10,000 fatalities per year in the U.S. This may sound horrible, but it corresponds to a life expectancy reduction for the average American of only 13 days. To put this risk to an individual in perspective, it is the risk an overweight person takes in adding 7 ounces to his weight, or the risk of smoking one pack of cigarettes every 4 months, or the risk of a woman going 2.5 years without a PAP test (only 50% of women get them), or the risk of not having a smoke alarm in your home (only 15% of all homes have them), and it is four times less than the risk of driving small cars rather than standard size cars. It is only 2.5 times the risk of electrocution in using the electricity. Whether these 10,000 fatalities per year (plus 10 million cases of respiratory disease and $13 billion in property damage) are "acceptable" is a matter of opinion, but our society is accepting them. There are programs for reducing the effects, hopefully down to the region of 2000 fatalities per year, but these are progressing very slowly and many experts believe they are on the wrong track. Nevertheless we seldom hear that the technology far handling the wastes from coal-burning is "yet to be established."
We now turn to the problem of nuclear waste. In estimating its effects, we use the recommendations agreed to (with small variations) by all prestigious national and international groups charged with responsibility in this area, including the National Academy of Sciences Committee on Biological Effects of Ionizing Radiation (BEIR), the United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR), the International Cornmission on Radiological Protection (ICRP), and national bodies in all advanced countries of the world. incidently these groups, as well as the vast majority of the involved scientific community (which they represent) reject the contention that radiation is more dangerous than it was believed to he a few years ago-this is largely a fabrication of our news media built upon very flimsy "new information" and ignoring the vast bulk of more substantial data, both old and new. The above-named groups give the 50%-lethal level for plutonium in the lung as 10-100 times higher than Winchester's figures, and contrary to her statement, they have never recommended or even suggested a lowering of allowable occupational exposure. EPA's justification for lowering allowable exposure to the public from 170 to 25 mrem/ year was done not because of increases in estimated effects of radiation, but because the reduction was deemed technologically achievable and the guiding philosophy is to keep radiation exposure as low as reasonably achievable.
The solution to the problem of high-level waste is to convert it into a rock and bury it where the rocks are, deep underground. It is easy to show' that if an atom of waste has the same probability of escape as an atom of average rock, and if all U. S. electricity were nuclear generated for millions of years, all of the accumulated waste would cause less than one fatality per year in the United States-compare this with the 10,000 per year from the wastes of coal-burning. There are some ways in which buried radioactive waste would be less secure than average rock, especially due to the fact that it will be thermally hot for 100-200 years; while all research to date indicates every reason for optimism, these matters are still under investigation which contributes a grain of truth to the statement that the technology is "yet to be established." however there are alternatives available regardless of how this research turns out, the waste can be diluted or its burial can be delayed to allow the heat source to decay away-so these studies are more for the purpose of optimum waste repository design than for establishment of feasibility. Moreover there are ways in which the buried waste would he more secure than "average" rock; it would he in a carefully selected geological environment virtually free of ground water, and it will probably be in a casing which would give million year protection not available to average rock. All in all, the one fatality per year derived above from average rock seems like a reasonable estimate for buried radioactive
In general, Winchester loses perspective on the dangers from high level waste. She states that it will stay poisonous "forever", but it loses 99.9% of its toxicity after 300 years, and 99.999% after 100,000 years by which time a 50%lethal dose would be over 6 lbs. converted into digestible form and eaten. There are other substances we dispose of with little control, and there are even natural rocks, for which 1 ounce or less would he lethal, and these truly maintain their toxicity forever. If the waste were dumped in the ocean-no one can claim we don't know how to do that-or buried in the sea bed, and if all of it leaked out immediately, the U.S. waste (if all our power were nuclear) would cause about 60 fatalities per year worldwide' through contamination of sea fond, still hundreds of times less than the 10,000 fatalities per year from coal burning. Incidentally, there would he essentially no harm to ocean eco-systems from such an eventuality.
The low-level waste contains thousands of times less radioactivity than the high-level waste, is therefore less dangerous by a corresponding factor, and is consequently buried with considerably less care in shallow trenches. While there was tremendous publicity about the tiny leakages front the Kentucky and New York State burial grounds, no member of the public was exposed to as much extra radiation from them3 as he would get from spending two days in a brick house rather than in a wooden house (brick contains more naturally radioactive material than wood), or from spending 8 hours in Colorado or Wyoming where natural radiation levels are higher than average. The chance that a single person will ever die from these past leaks is about one in 100,000. The reason for this low level of damage is that only a very tiny fraction of the buried material leaked out. However, it can be shown' that even if all of the radioactive material in these burial grounds were to leak out and become distributed through the soil, and if no special attention were paid to it there would still he only about one eventual fatality. The point here is that there is only about one chance in a billion each year for a given atom in the top layers of soil to find its way into a human body, and the vast bulk of the low-level radioactivity has a half life of less than 30 years, so it will decay away long before it can do harm.
Incidentally, a large fraction of the low level wastes are from hospitals and from research laboratories, with no relevance to nuclear power.
Winchester is a bit behind the times on the issue of radon emission from uranium mill tailings. The Nuclear Regulatory Commission has proposed requirements for operating mills to cover their tailings piles, and the Department of Energy has an active program for taking care of tailings at inoperative mills. The costs of covering tailings will be charged to the electricity consumer, but it will increase his bill for nuclear electricity by less than 0.1%.
On the other hand, little attention has been paid to the fact that coal contains small amounts of uranium, and hence that the ashes from coal burning also emit radon gas. It turns out that if the uranium mill tailings piles are covered, the radon problem from coal burning is considerably worse than from nuclear energy. The radon emitted from one year's production of coal ash will cause about 10 fatalities over the next 500 years.
Another viewpoint on this is that nuclear energy consumes uranium and hence reduces the exposure of future generations to radon. This greatly exceeds the harm done by radon from covered mill tailings so the overall effect of the nuclear industry is to reduce man's exposure to radon.
But if we are to worry about effects of radon, the real culprit is energy conservation. In insulating homes to save energy, radon emitted from the building materials and foundations of our houses is trapped inside for twice as long as it would he without the added insulation.5 If all homes were insulated to recommended standards, this would cause an extra 5000-10,000 fatalities per year in the U.S.
Intermediate and Trans-uranic Wastes
The intermediate and trans-uranic wastes discussed by Winchester are from military and research sources and have no relevance to nuclear power. However, these problems are being taken care of expeditiously and there is no reason to believe that they will even approach in importance the problem of high level waste discussed above.
The technology for controlling airborne emissions of radioactivity from nuclear plants is in place and functioning, so there is no need to speculate on its performance or on the "virtuous intentions" of government programs. Current radiation exposures are such that there is approximately one fatality per year in the U.S. from this source; if all U.S. power were nuclear and if we had a complete fuel reprocessing industry in operation, this number would rise to perhaps 20 fatalities per year, but this is still hardly comparable to the 10,000 fatalities per year from coal-burning air pollution.
There has never been a report of significant leakage of radioactivity into the environment from spent fuel storage, and according to all available information, there is no problem expected from this source even if the fuel were stored for 30 years or more. Hopefully the government will allow reprocessing to proceed in less than 30 years, in which case the problem disappears. It is very difficult to see how this problem can be even 1% as great as the problem of airborne emissions discussed above.
Decontamination and Decommissioning
There are now good estimates available on costs for decommissioning of nuclear power plants, and even for the most elaborate procedures, this would be only 10% of the original cost of the plant. This would raise the cost of electricity by only about 2%. The entombment or mothballing scheme mentioned by Winchester would reduce these costs about three-fold and it would be for only 100 years, which is something less than "forever." The residual material after decommissioning would be "low-level waste" and would represent a minute addition to the lowlevel waste problem discussed above.
Let me comment on the points in Winchester's last two paragraphs. On her numbered points:
(1) The effects of breach of waste repositories by later generations through drilling, mining, or bombing has been estimated and found to he less than effects of natural releases' discussed above.
(2) It is absolutely impossible for high-level waste to get into a configuration that would form a nuclear reactor; there just isn't enough fissile material in it.
(3) By the time ice sheets or other geologic processes could release the waste, its toxicity would be very low, lower than the toxicity of the original uranium ore mined to produce the waste. Thus our use of nuclear power alleviates this problem.
(4) The purpose of all the research now going on is to be certain that there are no processes that can lead to very rapid release.
We have many more serious long term waste problems than nuclear waste. For example, the arsenic we import into our country each year has 10,000 times the toxicity of one year's production of nuclear waste after 1000 years of decay. Moreover, the arsenic is not carefully buried 2000 feet underground, but most of it is used as an herbicide and hence is scattered about on the surface in food growing areas. The arsenic, of course, will retain its toxicity forever. But of course this problem can never approach the problem we now have of killing 10,000 people per year from the air pollution of burning coal, our only alternative to nuclear power.
1B. L. Cohen. "High Ievel Waste Irons Light Water Reactors, Rev. Mod. Physics 49, 1 (1977). An improved calculation is given in B. I.. Cohen, "Analysis, Critique, and Reevaluation of Water Intrusion Scenario
Studies". Nuclear Technology (in press)..
2 B. L. Cohen, ''Ocean Dumping of High Level Radioactive Waste", Nuclear Technology 47. 163 (1980).
3 C. Hardin, (Kentucky Dept. of Human Resources), private communication. He estimates the maximum exposure to any memberer of the public from Maxey Flats leakage as 0.1 mrem. The West Valley leakage was much smaller.
4B. L. Cohen and 11. N. Joss', ''A Generic Hazard Evaluation of loss' Level Waste Burial Grounds", Nuclear Technology, 11. 381 (1978)
5R. J. Rudnitz, et al, "Human Disease from Radion Exposures: The Impact of Energy Conservation in Buildings", Lawrence Berkley Lab. Report I, LBL-7809. Aug., 1978..