The very existence of plutonium is often viewed as the work of the devil.* As the most important ingredient in nuclear bombs, it may someday be responsible for killing untold millions of people, although there are substitutes for it in that role if it did not exist. If it gets into the human body, it is highly toxic. On the other hand, its existence is the only guarantee we have that this world can obtain all the energy it will ever need forever at a reasonable price. In fact, I am personally convinced that citizens of the distant future will look upon it as one of God's greatest gifts to humanity. Between these extremes of good and evil is the fact that if our nuclear power program continues to be run as it is today, the existence of plutonium will have no relevance to it except as a factor in technical calculations.
Clearly, there are several different stories to tell about plutonium. We will start with the future benefits, then discuss the weapons connection, and conclude with the toxicity question.
Fuel of the Future
As uranium occurs in nature, there are two types, U-235 and U-238, and only the former, which is less than 1% of the mixture, can be burned (i.e., undergo fission) to produce energy. Thus, present-day power reactors burn less than 1% of the uranium that is mined to produce their fuel. This sounds wasteful but it makes sense economically, because the cost of the raw uranium at its current price represents only 5% of the cost of nuclear electricity (see Chapter 13 Appendix). However, there is only a limited amount of ore from which uranium can be produced at anywhere near the current price, perhaps enough to provide lifetime supplies of the fuel needed by all nuclear power plants built up to the year 2025. Beyond that, uranium prices would escalate rapidly, doubling the cost of nuclear electricity within several decades.
Fortunately, there is a solution to this problem. The fuel for present-day American power plants is a mixture of U-238 and U-235. As the reactor operates, some of the U-238, which cannot burn, is converted into plutonium. This plutonium can undergo fission and thus serve as a nuclear fuel. In fact, some of it is burned while the fuel is in the reactor, enough to account for one-third of the reactor's total energy production. But some of it remains in the spent fuel from which it can be extracted by chemical reprocessing. This plutonium could be burned in our present power reactors, but an alternative is to use it in another type of reactor, the breeder, whose fuel is a mixture of plutonium and uranium (U-238). Much more of the U-238 in the breeder is converted to plutonium than in our present reactors, more than enough to replace all of the plutonium that is burned. Thus, a breeder reactor not only generates electricity, but it produces its own plutonium fuel with extra to spare. It only consumes U-238, which is the 99+% of natural uranium that cannot be burned directly; therefore, it provides a method for indirectly burning this U-238. With it, nearly all of the uranium, not less than one percent as in present type reactors, is eventually burned to produce energy. About a hundred times as much energy is thus derived from the same initial quantity. That means that instead of lasting only for about 50 years, our uranium supply will last for thousands of year. As a bonus, the environmental and health problems from uranium mining and mill tailings will be reduces a hundred fold. In fact, all uranium mining could be stopped for about 200 years while we use up the supply of U-238 that has already been mined and is now in storage.
Deriving 100 times as much energy from the same amount of uranium fuel means that the raw fuel cost per kilowatt-hour of electricity produced is reduced correspondingly. In fact, the fuel costs per unit of useful energy generated in a breeder reactor are equivalent to those of buying gasoline at a price of 40 gallons for a penny! (see Chapter 13 Appendix). Instead of contributing 5% to the price of electricity as in present-type reactors, the uranium cost then contributes only 0.05% in a breeder reactor. If supplies should run short, we can therefore afford to use uranium that is 20 times more expensive, for even that would raise the cost of electricity by only (20 x .05 =) 1%. How much uranium is available at that price?
The answer is effectively infinite because it includes uranium separated out of seawater.1 The world's oceans contain 5 billion tons of uranium, enough to supply all the world's electricity through breeder reactors for several million years. But in addition, rivers are constantly dissolving uranium out of rock and carrying it into the oceans, renewing the oceans' supply at a rate sufficient to provide 25 times the world's present total electricity usage.2 In fact, breeder reactors operating on uranium extracted from the oceans could produce all the energy humankind will ever need* without the cost of electricity increasing by even 1% due to raw fuel costs.
The fact that raw fuel costs are so low does not mean that electricity from breeder reactors is very cheap. The technology is rather sophisticated and complex, involving extensive handling of a molten metal (liquid sodium) that reacts violently if it comes in contact with water or air. Largely as a result of the safety precautions required by this problem, the cost of electricity from the breeder will be substantially higher at today's uranium prices than that from reactors now in use.3 Nevertheless, France, England, and the Soviet Union have continued with developing breeder reactors, and several other countries, including Germany and Japan, are involved to a lesser degree. The American program was at the forefront 20 years ago, but it became a political football and is now essentially dead.
On the surface, the opposition to the U.S. breeder reactor is based on the fact that uranium supplies are plentiful and cheap, leaving little incentive for an expensive development program at this time (less expensive research is continuing, most notably in a test reactor at the Hanford site in Washington State). Why, then, have other countries continued to press on with their development programs? First, even if development goes forward at the hoped-for pace, it will be many years before the first commercial breeder can become operational and many more before its use would become widespread; it is better to start up any new technology slowly, allowing the "bugs" to be worked out before a large number of plants is built. Second, we are not that certain about our uranium resources; they may be substantially below current estimates. Having the breeder reactor ready would be a cheap insurance policy against that eventuality, or against any sharp increase in uranium prices for whatever the reason. And third, the breeder reactor development program has substantial momentum, with lots of scientists, engineers, and technicians deeply involved. It is much more efficient to carry the program to completion now than to stop it, allow these people to become scattered, and then start over with a new team of personnel later.
Not far beneath the surface, there is substantial opposition to the breeder because of distaste for plutonium and general opposition to nuclear power. There are also some fears about the safety of breeder reactors, but experts on that subject (of which I am not one) maintain that they are extremely safe, and even safer than present reactors.3,8 They have the important safety advantage of operating at normal pressure rather than at very high pressure, as is the case for present reactors. There are therefore no forces tending to enlarge cracks or to blow the coolant out of the reactor (this is the blowdown discussed in Chapter 6.).
A key part of the breeder reactor cycle is the reprocessing of spent fuel to retrieve the plutonium. In fact, this must be done with the spent fuel from present reactors in order to obtain the plutonium necessary to fuel the first generation of breeder reactors. As long as there is no reprocessing, the plutonium occurs only in spent fuel, where it is so highly dilute (½ of 1% of the total) that it is unusable for any of the purposes usually discussed. Moreover, spent fuel is so highly radioactive (independently of its plutonium content) that it can only be handled by large and expensive remotely controlled equipment. It therefore cannot be readily stolen or used under clandestine conditions. Without reprocessing, there is no use for plutonium for good or evil.
It should also be recognized that plutonium plays only a minor role in waste disposal problems, and a negligible role in reactor accident scenarios. Thus, as long as there is no reprocessing, which is the present status in the United States commercial nuclear power program, plutonium issues have no direct relevance to the acceptability of nuclear power.
However, it is my personal viewpoint that it is immoral to use nuclear power without reprocessing spent fuel. If we were simply to irretrievably bury it, we would consume all the rich uranium ores within about 50 years. This would deny future citizens the opportunity of setting up the breeder cycle, the only reasonably low-cost source of energy for the future of which we can be certain. By such action, our generation might well go down in history as the one that denied humankind the benefits of cheap energy for millions of years, a fitting reason to be eternally cursed. On the other hand, if we develop the breeder reactor, we may go down in history as the generation that solved the world's energy problems for all time. Future generations might well remember and bless us for millions of years.
Unfortunately, the people in control are not worried about the long-range future of mankind. People in the nuclear power industry are concerned principally about the next 30 or 40 years, and politicians rarely extend their considerations even that far into the future. Whether or not we do reprocessing will have little impact over these time periods; thus the prospects for early reprocessing are questionable.
The situation was very different only a few short years ago. A large reprocessing plant capable of servicing most of the power plants now operating in the United States was constructed near Barnwell, South Carolina, by a consortium of chemical companies. The main part of the plant, costing $250 million, was completed in 1976, but two add-ons that would have cost about $130 million were delayed by government indecision. Since the add-ons would not be needed for several years, it was expected that the main part of the plant could be put into immediate operation.
At that critical point, the U.S. Government decreed an indefinite deferral of commercial reprocessing. The reason for the decree involved our national policy on discouraging proliferation of nuclear weapons, which will be discussed later in this chapter, but from the viewpoint of the plant owners, it was a disaster. They had been strongly encouraged to build the plant by government agencies for example, federally owned land was made available to them for purchase and every stage of the planning was done in close consultation with those agencies. They had scrupulously fulfilled their end of the bargain, laying out a large sum of money, and now they were left with a plant earning no income.
By the time the Reagan Administration withdrew the decree forbidding reprocessing 5 years later, the owners had lost heart in the project and were unwilling to provide the money, now increased to over $200 million, to provide the add-ons. The Barnwell plant was abandoned. It is generally recognized that there will be no commercial reprocessing in the United States unless the government provides assurances that money invested would be compensated if the project were again terminated by political decree, and guarantees to purchase the plutonium it produces. The latter requirement is necessary because the Barnwell plant was originally built with the understanding that utilities could purchase the plutonium to fuel present reactors, but the government has not taken action to allow this and probably will never do so. It is now widely agreed that it would be better to save the plutonium for breeder reactors. Since there are no commercial breeder reactors in the United States and will not be any for many years, this leaves the government as the only customer for the plutonium from a reprocessing plant.
Aside from the idealistic considerations of providing energy for future generations, an additional driving force behind getting reprocessing plants into operation is their contribution to waste management. Power plants are having difficulty in storing all of the spent fuel they are discharging; reprocessing gives them an outlet for it. Furthermore, the amount of material to be buried is very much reduced if the uranium is removed in reprocessing. There is also considerably more security in burying high-level waste converted to glass and sealed inside a corrosion-resistant casing, than in burying unreprocessed spent fuel encased in asphalt or some similar material.
On the other hand, there has been strong opposition to reprocessing. There have been well publicized attacks on its environmental acceptability, ignoring the contrary evidence in the scientific literature in favor of "analyses" by "environmental groups" tailored to reach the desired conclusion. There were widely publicized economic analyses of unspecified origin claiming that reprocessing was a money-losing proposition, even when the real professionals in the business considered it to be economically advantageous.9 There was a considerable amount of publicity for a paper issued by the DOE claiming that the Barnwell plant was technically flawed,10 but it turned out the paper was by a scientist with little experience in the field who had never visited the plant and was confused over differences between reprocessing fuel from present power reactors and breeder reactors; the paper had accidentally slipped through the DOE reviewing process and was disavowed and strongly critiqued by the head of the division that had issued it.11
A major part of this opposition to reprocessing came from those opposed to nuclear power in general for political and philosophical reasons. They realized that it was too late to stop the present generation of reactors, but if they could stop reprocessing, nuclear power could have no long-term future. However, the most important opposition to reprocessing came from its possible connection to nuclear weapons. If there is a connection between nuclear electricity and nuclear explosives, reprocessing is the bottleneck through which it must pass. We now turn to a discussion of that matter.
Proliferation of Nuclear Weapons
Everyone agrees that nuclear weapons can have very, very horrible effects and that it is exceedingly important to avert their use against human targets. One positive step in this direction is to minimize the number of nations that have them available for use that is, to avoid the proliferation of nuclear weapons. To what extent do nuclear power programs frustrate that goal?
If a nation has a nuclear power reactor and a reprocessing plant, it could reprocess the spent fuel from the reactor to obtain plutonium, and then use that plutonium to make bombs. On the other hand, there are much better ways for nations to obtain nuclear weapons. There are two* practical fuels for nuclear fission bombs: U-235, which occurs in nature as less than 1% of normal uranium, from which it must be removed by a process known as "isotope separation," and plutonium, which can be produced in nuclear reactors and converted into usable form through reprocessing. Either method can produce effective bombs, although the best bombs use a combination of both. Both the isotope separation and the reactor-reprocessing methods are used by all five nations known to have nuclear weapons, the United States, the Soviet Union, Great Britain, France, and China. (India has also exploded a nuclear device but claims that it was for nonweapons purposes.)
However, there is a subtle aspect to producing plutonium by the reactor - reprocessing method, and to explain it we will divert briefly to review our Chapter 7 discussion of how a plutonium bomb works. There are two stages in its operation: first, there is an implosion in which the plutonium is blown together and powerfully compressed by chemical explosives that surround it, and then there is the explosion in which neutrons are introduced to start a rapidly escalating chain reaction of fission processes that release an enormous amount of energy very rapidly to blow the system apart. All of this takes place within a millionth of a second, and the timing must be precise if the explosion phase starts much before the implosion process is completed, the power of the bomb is greatly reduced. In fact, one of the principal methods that has been considered for defending against nuclear bombs is to shower them with neutrons to start the explosion early in the implosion process, thereby causing the bomb to fizzle. For a bomb to work properly, it is important that no neutrons come upon the scene until the implosion process approaches completion.
Plutonium fuel, Pu-239, is produced in a reactor from U-238, but if it remains in the reactor it may be converted into Pu-240, which happens to be a prolific emitter of neutrons. In a U.S. power plant, the fuel typically remains in the reactor for 3 years, as a consequence of which something like 30% of the plutonium produced comes out as Pu-240. If this material is used in a bomb, the Pu-240 produces a steady shower of 2 million neutrons per second,12 which on an average would reduce the power of the explosion tenfold, but might cause a much worse fizzle. In short, a bomb made of this material, known as "reactor-grade plutonium," has a relatively low explosive power and is highly unreliable. It is also far more difficult to design and construct.
A much better bomb fuel is "weapons-grade plutonium," produced by leaving the material in a reactor for only about 30 days. This reduces the amount of Pu-240 and hence the number of neutrons showering the bomb by a large factor.
One might consider trying to use a U.S.-type power reactor to produce weapons-grade plutonium by removing the fuel for reprocessing every 30 days, but this would be highly impractical because fuel removal requires about a 30-day shutdown. Moreover, the fuel for these power reactors is very expensive to fabricate because it must operate in a very compact geometry at high temperature and pressure to produce the high-temperature, high-pressure steam needed to generate electricity.
It is much more practical to build a separate plutonium production reactor designed not to generate electricity but rather to provide easy and rapid fuel removal in a spread-out geometry with fuel that is cheap to fabricate because it operates at low temperature and normal pressure. Moreover, it can use natural uranium rather than the very expensive enriched uranium needed in power reactors. For a given quantity of fissile material, the former contains 4 times as much of the U-238 from which plutonium is made, hence producing 4 times as much plutonium. A plutonium production reactor costs less than one-tenth as much as a nuclear power plant13 and could be designed and built much more rapidly. All of the plutonium for all existing military bombs has been produced in this type of reactor except in the Soviet Union where a compromise design allowing both electricity generation and plutonium production is employed (see Chapter 7).
Another alternative would be to use a research reactor, designed to provide radiation for research applications* rather than to generate electricity. At least 45 nations now have research reactors, and in at least 25 of these there is a capability of producing enough plutonium to make one or more bombs every 2 years. Research reactors are usually designed with lots of flexibility and space, so it would not be difficult to use them for plutonium production.
A plant for generating nuclear electricity is by necessity large and highly complex, with most of the size and complexity due to reactor operation at a very high temperature and pressure, the production and handling of steam, and the equipment for generation and distribution of electricity. It would be impossible to keep construction or operation of such a plant secret. Moreover, only a very few of the most technologically advanced nations are capable of constructing one. No nation with this capability would provide one for a foreign country without requiring elaborate international inspection to assure that its plutonium is not misused. A production or research reactor, on the other hand, can be small and unobtrusive. It has no high pressure or temperature, no steam, and no electricity generation or distribution equipment. Almost any nation has, or could easily acquire, the capability of constructing one, and it probably could carry out the entire project in secret. There would be no compulsion to submit to outside inspection.
In view of the above considerations, it would be completely illogical for a nation bent on making nuclear weapons to obtain a power reactor for that purpose. It would be much cheaper, faster, and easier to obtain a plutonium production reactor; the plutonium it produces would make much more powerful and reliable bombs with much less effort and expense.
The only reasonable scenario in which U.S.-type power reactors might be used is if a nation decided it needs nuclear weapons in a hurry. In such a situation, 1 or 2 years could be saved if a power reactor were available and a production or large research reactor were not.13 However, nearly all nations that have a power reactor also have research reactors. Moreover, it would be most unusual for this time saving to be worth the sacrifice in weapons quality.
But obtaining plutonium is not the only way to get nuclear weapons. The other principal method is to develop isotope separation capability. Nine nations now have facilities for isotope separation,13 and others would have little difficulty in acquiring it. A plant for this purpose, costing $20-200 million, could provide the fuel for 2-20 bombs per year and could be constructed and put into operation in 3-5 years.13 The product material would be very easy to convert into excellent bombs, much easier than making a plutonium bomb even with weapons-grade plutonium.
This assessment is based on present technology, but several new, simpler, and cheaper technologies for isotope separation are under development and will soon be available. They will make the isotope separation route to nuclear weapons even more attractive. There are also new technologies under consideration for producing plutonium without reactors, which may make that route more attractive.
The way I like to explain the problem of nuclear weapons proliferation is to consider three roads to that destination: (1) isotope separation, (2) plutonium production with research or production reactors, and (3) plutonium production in U.S.-type power plants, with (2) and (3) requiring reprocessing. The first two roads are much more attractive than the third from various standpoints; they are like super highways, while the third is like a twisting back country road. In this analogy, how important is it to block off the third road while leaving the first two wide open? The link between nuclear power and proliferation of nuclear weapons is a weak and largely insignificant one.*
But that is certainly not the impression the public has received. The great majority of stories about nuclear weapons proliferation involves nuclear power plants. They generally give the impression that without nuclear power there would be no proliferation problem. They rarely differentiate between a power reactor and other types more suitable for making bombs. I believe most Americans think that the Iraqi reactor destroyed by an Israeli air raid was a nuclear power plant, when in fact it was a large research reactor.
Even though nuclear power plants are only a minor source of weapons proliferation, nobody is saying that elaborate precautions should not be taken to see that the plutonium in them is not used for that purpose. The programs for dealing with that problem are known as "safeguards". They are administered by the International Atomic Energy Agency (IAEA) based in Vienna. The IAEA has teams of inspectors trained and equipped to detect diversion of plutonium. In nations subject to safeguards programs, the IAEA has access to all nuclear power plants, reprocessing plants, and other facilities involved in handling plutonium. (The principal other facility would be for fabricating plutonium fuel for use in breeder reactors or perhaps in present reactors.) There has been an impressive development in techniques and equipment for carrying out these inspections. For example, the Barnwell reprocessing plant developed an automatic computer-controlled system that gives a warning in less than an hour if any plutonium in the plant should not be where it is supposed to be. With such measures and IAEA inspectors on the scene or making unannounced visits, it would be very difficult for a nation to divert plutonium from its nuclear power program without the rest of the world knowing about it long before the material could be converted into bombs.
These safeguards would be much easier to circumvent with a production or research reactor or with an isotope separation plant. These are much smaller operations with far less support needed from foreign suppliers; it would not be difficult to build them clandestinely. The IAEA safeguards system thus does much more to block off the twisting back country road than the super highways.
One would have thought that these safeguards would be enough attention paid to the back country road, but the Carter Administration saw fit to go a step further. It decided to try to prevent the acquisition of reprocessing technology by nonnuclear weapons nations. As you may recall, reprocessing is a bottleneck that must be passed if nuclear power plants are to be used to make bomb materials; thus the goal of the government was, in principle, a desirable one. However, the method for implementing it was disastrous.
At that time (1977), Germany was completing a deal to set up a reprocessing plant in Brazil, Japan was building a plant, and France was negotiating the sale of plants to Pakistan and Korea. The Carter goal was to stop these activities through moral and political pressure. To set the moral tone for this effort essentially to "show that our heart is in the right place" he decided to defer indefinitely the reprocessing of commercial nuclear fuel in the United States.* This was the move that prevented the Barnwell plant from operating.
There were several problems with this approach. One was that the U.S. Government continued to do reprocessing in its military applications program, which was something of a dilution of the high moral tone being advertised. Another was that Germany had just won the Brazilian contract after stiff bidding competition with U.S. firms. The Germans therefore interpreted the U.S. initiative as sour grapes over the loss of business. But a much bigger problem arose from the political pressure used: the United States delayed and threatened to stop shipments of nuclear fuel to nations that would not cooperate.
American manufacturers had built up a thriving export business of selling reactors to countries all over the world. Part of the deals was a guaranteed future supply of fuel for the reactors; this meant U.S. Government participation in the contracts, because it possessed the only large-scale facilities for isotopic enrichment of uranium. These sales contracts had no clauses allowing interruption of the fuel supply no one would spend hundreds of millions of dollars for a power plant without a guaranteed fuel supply so the delays and threatened withholding of shipments by the United States represented a direct and illegal breach of contract. Even nations with no interest in reprocessing were deeply upset by the very principle of this action. I remember sitting in a frenzied session of a meeting in Switzerland on this subject. The session was in German, for the benefit of Swiss journalists, and I did not understand much of it, but I kept hearing the word "nonproliferationpolitik" accompanied by expressions of intense anger and banging on the table. At one point Yugoslavia, which purchased a Westinghouse reactor, was close to breaking off diplomatic relations with the United States over this issue.
Not only was withholding fuel shipments a breach of contract, but it was a violation of the International Treaty on Nonproliferation of Nuclear Weapons. That treaty states that a nonweapons nation that signs the treaty is entitled to a secure and uninterrupted supply of fuel for its power reactors. Thus the United States became the first nation to violate that treaty, which is the most important safeguard the world has against proliferation. Incidentally, this furor in Europe, Asia, and South America over the Carter initiative received virtually no media coverage in this country.
But the worst problem with the Carter initiative was that it failed to achieve much in the way of results. The United States had enough political leverage over South Korea to force that country to cancel its purchase of a reprocessing plant. France cancelled its sale to Pakistan, probably in recognition of the fact that Pakistan had expressed ambitions for building nuclear weapons, but perhaps also partly as a result of American political pressure. However, the German deal with Brazil was not cancelled in spite of constant political pressure, including several face-to-face meetings between President Carter and German Chancellor Schmidt. The Japanese reprocessing plant was completed and started up. No other reprocessing activity anywhere in the world except in the United States was stopped by the Carter initiative.
While the Carter initiative had little impact on the international proliferation problem, it did have two very important negative effects on this country: it prevented the start-up of the Barnwell plant, as discussed earlier, which has had a long-lasting devastating effect on commercial reprocessing in the United States; and it has completely ruined the U.S. reactor export business. Several nuclear power plants are purchased by foreign countries every year, and at one time, American companies got the lion's share of the business. In recent years, however, the United States has become universally regarded as an unreliable supplier. France and Germany get nearly all of the business. The Soviet Union and Western Europe have become important international suppliers of fuel.
But perhaps the most disturbing effect of our national nonproliferation politics was that it caused us to lose most of our influence in international nonproliferation efforts. Before 1977, the United States played leading roles in all international programs and planning to discourage proliferation. We were the leading force in drawing up the international nonproliferation treaty and in getting it ratified by most nations of the world. We led the way in seeking and developing technological methods of assuring compliance, and of limiting problems. However, since the United States "went its own way," we have lost much of our credibility and have had much diminished influence in international nonproliferation programs.
In trying to understand the failure of the Carter effort to stop the spread of reprocessing technology, it is important to consider how effective it might be in stopping weapons proliferation. One obvious limitation was that it was designed only to obstruct the back country road, doing little to obstruct the two main highways to proliferation. Most of the world outside the United States recognized that point and, hence, regarded the Carter initiative contemptuously.
If a nation decides to develop nuclear weapons, lack of reprocessing facilities would hardly stop it. Fourteen nations now have such facilities, and others would have little difficulty in developing them. A commercial reprocessing plant designed to operate efficiently and profitably with minimal environmental impact is a rather expensive and complex technological undertaking, but the same is not true for a plant intended for military use where the only concern is obtaining the product. Construction of such a plant requires no secret information and no unusual skills or experience. Details of reprocessing technology have been described fully in the open literature. It was estimated13 in 1977 that a crude facility to produce material for a few bombs could be put together and operated by five people at a cost of $100,000. A plant capable of longer-term production of material for eight bombs per year could be built and operated by 15 people, half of them engineers and the other half technicians, at a cost of $2 million. Either of these plants, or anything in between, could probably be built and operated clandestinely.
Thus, stopping reprocessing of commercial power reactor fuel is hardly an effective way of preventing weapons proliferation, and it is not widely viewed as such outside of the United States. On the other hand, reprocessing provides an important source of fuel for present reactors that could tide a needy nation over for a few years in an emergency. It is, furthermore, the key to a future system of breeder reactors which is the only avenue open to many nations for achieving energy independence. Unlike this country, with its abundant supplies of coal, oil, gas, rich uranium ores, and shale oil potential, many nations are very poor in energy resources. These include not only heavily industrialized nations like France and Japan, but nations aspiring to that status like Brazil, Argentina, and Taiwan. It is not difficult to understand why these nations are unwilling to trust their very survival to the mercy of Arab sheiks or the whims of American presidents for the indefinite future. They desperately want some degree of energy independence, and reprocessing technology is the key to the only way they can foresee of ever achieving it.
Above and beyond the practical difficulties U.S. nonproliferation policy has encountered, we might ask how important is its goal. There never was any hope that it could prevent a major industrialized nation from developing a nuclear weapons arsenal there are now five nations with such arsenals. It could only hope to prevent a less-developed country like Brazil from taking such a step. By signing the international nonproliferation treaty, Brazil has renounced any such intentions. A Brazilian reprocessing plant would be subject to very close scrutiny by IAEA inspectors to see that its plutonium is not diverted for use in weapons. Add to this the facts that the plutonium it produces is ill-suited for use in weapons, and that a separate, secret plant could be built and used to produce weapons grade plutonium, and it seems clear that stopping a Brazilian reprocessing plant will not be the action that prevents that nation from developing nuclear weapons.
But suppose it did allow Brazil to develop a small arsenal of nuclear weapons what could it do with it? It could threaten its neighbors, but they could easily be guaranteed against attack by the large nuclear weapons powers; Japan, Germany, and Scandinavia, for example, do not feel threatened by Russian or Chinese nuclear weapons because they are covered by the U.S. umbrella. There are few places in the world where a small nation could use a nuclear bomb these days without paying a devastating price for its action.
If one attempts to develop scenarios that might lead to a major nuclear holocaust, fights over energy resources such as Middle East oil must be at or near the top of the list. Anything that can give all of the major nations secure energy sources must therefore be viewed as a major deterrent to nuclear war. Reprocessing of power reactor fuel can provide this energy security, and therefore has an important role in averting a nuclear holocaust. That positive role of reprocessing is, to most observers, more important than any negative role it might play in causing such a war through proliferation of nuclear weapons.
After all of this discussion of proliferation, it is important to recognize that the use of nuclear power in the United States has no connection to that issue. If we stopped our domestic use of nuclear power, this would not deter a Third World nation from obtaining nuclear weapons, or conversely, use of nuclear power in the United States in no way aids such a nation in obtaining them. The only possible problems occur in transfer of our technology to those countries.
One of the most disturbing aspects of the proliferation problem is the utter lack of information on it that has been made available to the American public. I doubt if more than 1% of the public has any kind of balanced understanding of the subject. Based on the little information provided to them, most people have a distinct impression that our use of nuclear power adds substantially to the risk of nuclear war.
This impression has been cemented by the tactic of anti-nuclear activists to tie nuclear weapons and nuclear power together in one package, purposely making no effort to distinguish between the two. Consider this from an Evans and Novak column after the November 1982 election: "Eight states and the District of Columbia voted for a nuclear freeze [on weapons], but the one crucial issue on any ballot Maine's referendum on [shutting down] the Yankee Power Plant the pronukes won." The terms "antinuke" and "pronuke" are often used interchangeably in referring to nuclear weapons and power plants for generating electricity.
A Tool for Terrorists?
A rather separate issue linking nuclear power with nuclear weapons is the possibility that terrorists might steal plutonium to use for making a bomb. This issue was first brought to public attention in 1973 in a series of articles by John McPhee in the New Yorker magazine later published as a book.14 He reported on interviews with Dr. Ted Taylor, a former government bomb designer. Taylor had been worried about this problem for some time and had tried to convince government authorities to tighten safeguards on plutonium, which were quite lax at that time, but he could not stir the bureaucracy. The McPhee articles provided an instant solution to the lax safeguards problem over the next 2 years, they were dramatically tightened. They also made Ted Taylor an instant hero of the antinuclear movement and the terrorist bomb issue stayed in the limelight for several years.
Let's take a look at that issue. To begin, consider some of the obstacles faced by terrorists in obtaining and using a nuclear bomb.15 Their first problem would be to steal at least 20 pounds of plutonium, either from some type of nuclear plant or from a truck transporting it. Any plant handling this material is surrounded by a high-security fence, backed up by a variety of electronic surveillance devices, and patrolled by armed guards allowing entry only by authorized personnel. The plutonium itself is kept in a closed-off area inside the plant, again protected by armed guards who allow entry only to people authorized to work with that material. These people must have a security clearance, which means that they are investigated by the FBI for loyalty, emotional stability, personal associations, and other factors that might suggest an affinity for terrorists activities. When they leave the area where plutonium is stored or used, they must pass through a portal equipped to detect the radiation emitted by plutonium. It will readily detect as little as 0.01 percent of the quantity needed to make a bomb, even if it were in a metal capsule swallowed by the would-be thief. Plants conduct frequent inventories designed to determine if any plutonium is missing. In some plants these inventories are carried on continuously under computer control so as to detect rapidly any unauthorized diversion. There are elaborate contingency plans for a wide variety of scenarios.16 When it is transported, plutonium is carried in an armored truck with an armed guide inside. It is followed by an unmarked escort vehicle carrying an armed guard. All guards are expert marksmen qualified periodically by the National Rifle Association.
The truck and the escort vehicles have radio telephones to call for help if attacked, and they report in regularly as they travel. There are elaborate plans for countermeasures in the event of a wide variety of problems.17
The only significant transport of plutonium in connection with nuclear power would be of ton-size fuel assemblies in which the plutonium is intimately mixed with large quantities of uranium from which it would have to be chemically separated before use in bombs. If terrorists are interested in stealing some plutonium, it would be much more favorable for them to steal it from some aspect of our military weapons program where it is frequently in physical sizes and chemical forms easier to steal and much easier to convert into a bomb. That also would give them weapons-grade plutonium, which is much more suitable for bomb making than the reactor-grade plutonium from the nuclear power industry. It would be even better for them to steal some high-purity U-235 (which is not used in nuclear power activities) from our military program, since that is very much easier to make into a bomb. Of course, their best option would be to steal an actual military bomb.
It should be recognized that all of this technology for safeguarding plutonium is now used only for material in the government weapons program. There is essentially no plutonium yet associated with nuclear power. One might wonder how it would be possible to maintain such elaborate security if all of our electricity were derived from breeder reactors fueled by plutonium. The answer is that the quantities of plutonium involved would not be very large. All of the plutonium in a breeder reactor would fit inside a household refrigerator,* and all of the plutonium existing at any one time in the United States would fit into a home living room. The great majority of it would be inside reactors or in spent fuel, where the intense radiation would preclude the possibility of a theft. As in the case of radioactive waste, the small quantities involved make very elaborate security measures practical.
There have been charges that all these security measures with armed guards would turn this country into a police state. However, the total number of people required to safeguard plutonium would be only a small fraction of the number now used for security checking in airports to prevent hijacking of airplanes. That force has hardly given our country a police state character.
If terrorists do manage to steal some plutonium from nuclear power operations and evade the intensive police searches that are certain to follow their theft, their next problem is to fabricate it into a bomb. Ted Taylor's assessment18 of that task is indicated by the following quote:
Under conceivable circumstances, a few persons, possibly even one person working alone, who possess about 10 kilograms of plutonium and a substantial amount of chemical high explosive could, within several weeks, design and build a crude fission bomb.
By a "crude fission bomb" we mean one that would have an excellent chance of exploding with the power of at least 100 tons of chemical high explosive. . . . The key persons or person would have to be reasonably inventive and adept at using laboratory equipment. . . . They or he would have to be able to understand some of the essential concepts and procedures that are described in widely distributed technical publications concerning nuclear explosives, nuclear reactor technology, and chemical explosions [and] would also have to be willing to take moderate risks of serious injury or death.
Taylor suggested some available publications that would be useful. I read them, but the principal message I derived was that designing a bomb would be even more difficult than I had previously believed it to be. Perhaps some obscure statements in those publications contain the key to solving the problem; they would be readily recognized by a professional government bomb designer, but they were not at all recognizable to me.
In order to better understand the difficulties a terrorist would face in fabricating a bomb, let us consider opinions from some other professional government bomb designers. The following statement was obtained from J. Carson Mark of Los Alamos National Laboratory19:
I think that such a device could be designed and built by a group of something like six well-educated people, having competence in as many different fields.
As a possible listing of these, one could consider: A chemist or chemical engineer; a nuclear or theoretical physicist; someone able to formulate and carry out complicated calculations, probably requiring the use of a digital computer, on neutronic and hydrodynamic problems; a person familiar with explosives; similarly for electronics; and a mechanically skilled individual.
Among the above (possibly the chemist or the physicist) should be one able to attend to the practical problems of health physics.
Clearly depending on the breadth of experience and competence of the particular individuals involved, the fields of specialization, and even the number of persons, could be varied, so long as areas such as those indicated were covered.
Note that this assessment is more optimistic from the public security viewpoint than Ted Taylor's statement. An even more optimistic assessment was given by E. M. Kinderman of Stanford Research Institute20:
Several people, five to 10 with a hundred thousand dollars or so could do the job if the people were both dedicated to their goal and determined to pursue it over two years or more.
One or a few competent physicist-engineers could probably arrive at a tentative design in a year or so.
A chemical engineer and a metallurgist could . . . construct the essential equipment, make essential tests, and alone or with some help, operate a plant to produce the product dictated by the bomb designer.
Others would be needed for the design and construction of the miscellaneous parts. . . . It is likely that the team will produce something with a force equivalent to 50 to 5,000 tons of TNT* . . . [and it] will weigh less than one ton.
Aside from the three statements quoted, the only other information from bomb experts with which I am familiar was a government statement21:
...a dedicated individual could conceivably design a workable device. Building it, of course, is another question and is no easy task.
However, we also recognize that it is conceivable that a group with knowledge and experience in explosives, physics, metallurgy, and with the requisite financial resources and nuclear materials could, over a period of time, perhaps even build a crude nuclear explosive.
The principal information given to the public via the media was based on the separate efforts of an unnamed MIT student, and John Phillips, a Princeton student. The MIT student was hired for a summer to see how far he could get in trying to make a bomb, and the story was told on a NOVA television program. He produced a design and fabrication procedure on paper which a Swedish expert judged to have "a small but real chance of exploding with a force of 100-1000 tons [of TNT]." It was not stated whether this referred to a bomb made from weapons-grade, or reactor-grade, plutonium. It was also not clear what is meant by a Swedish expert, since Sweden has never built a bomb and has always professed no interest in such an undertaking.
A U.S. government expert who examined the MIT student's fabrication procedure told me that anyone trying to follow it would almost surely be blown up by the chemical explosives long before his bomb was completed. Obviously the student had no experience in handling high explosives. This is an example of the various problems a terrorist would face. There is nothing secret about handling high explosives, but few people are experienced in this type of work. The handling includes cutting and shaping it, and attaching things to it I have 30 years of experience in experimental physics and have mastered numerous techniques, but I would never consider undertaking anything so dangerous.
The effort by the Princeton student, John Phillips, was much more widely publicized. He made extravagant claims that his bomb would explode with a force of more than 10,000 tons of TNT. He took on a publicity agent, wrote a book, appeared on many TV and radio shows, received very wide newspaper coverage, and even ran for Congress.
What he claimed to have produced was a design for a bomb in a term paper prepared for a physics course. I spoke to his professor in that course, who said that there was nothing in his paper that would ordinarily be called a design. There were only crude sketches without dimensions. There were no calculations to support his claim that his bomb would work. He had collected a lot of information that would be useful in designing a bomb, for which the professor gave him an A grade.
Phillips was being called by media people so frequently that he had to have a separate telephone installed in his dormitory for that purpose. His professor told me that he himself had been contacted by many newsmen, but they never printed what he told them they only trumpeted that Phillips had designed a workable bomb.
Several people have told me that professional government bomb designers have said that a design for a bomb by some student would work. I know that this could not be true because it would be a very serious breach of security regulations for a person who was ever involved with the government program to comment on a design that is available to the public. Note that the MIT student's design was judged by a "Swedish expert." With regard to such claims about Phillips' design, no professional could possibly consider a sketch without dimensions to be a design capable of being evaluated for performance. Science and technology are highly quantitative disciplines, but apparently Phillips does not understand that fact.
There have been numerous statements in newspapers, including our university paper, that any college student could design a nuclear bomb. In reply, I published an offer in our university paper of an unqualified A grade in both of the two courses on nuclear energy that I was teaching for any student who can show me a sketch of a workable plutonium bomb together with a quantitative calculation showing that it would work. My offer has been repeated about 10 times over the last 15 years. Three students turned in papers, but none of them had as much as 5% of what could be called a design.
All of this discussion has been about designs on paper, but as is clear from the above quoted statements by experts, that is only a small part of the task faced by terrorists. The fabrication requires a wide degree of expertise and experience in technical areas. It requires people capable of carrying out complex physics and engineering computations, handling hazardous materials, arranging electronically for a hundred or so triggers to fire simultaneously within much less than a millionth of a second, accurately shaping explosive charges, attaching them precisely and connecting the triggers to them, and so on. Where would terrorists find this expertise?
Experienced and talented scientists and technicians generally enjoy well-paid and comfortable positions in our society and hence are not likely to be inclined toward antisocial activity. Recruiting would have to be done under strictest secrecy, which would have to be maintained over the development period of many weeks. Even one unsuccessful recruiting attempt could blow their operation. Moreover, a participant would face a high risk of being killed in this work. And if the plot were discovered he would face imprisonment, not to mention an end to a promising career. Terrorists would surely face severe difficulty in obtaining the needed expertise.
But suppose, somehow terrorists succeeded in stealing the plutonium and making the bomb. Let us say it has the explosive force of 300 tons of TNT, which is an average of the various estimates by experts. What could they do with it?
We usually think of a nuclear bomb as something capable of destroying a whole city, but that refers to bombs many thousands of times larger. A bomb of this size would roughly be capable of destroying one city block, or one very large building. Ted Taylor uses,18 as an example, the World Trade Center in New York City, which sometimes contains 50,000 people. That is the origin of the oft-quoted statement that one of these bombs could kill 50,000 people. It could also kill a similar number in a sports stadium by showering them with radiation and burning them with searing heat.
However, if killing 50,000 people is the terrorists' desire, there are many easier alternatives for accomplishing it. They could:
Any imaginative person could add many more items to this list.
Terrorists with a nuclear bomb would probably first try to use it as an instrument for blackmail. But nonnuclear tactics would be equally useful for that purpose. Unlike the nuclear bomb situation, there are plenty of people with all the know-how to carry out these actions.
Also unlike the nuclear bomb situation, we are doing nothing to avert their implementation, although there are many things we might do. We could guard ventilation systems of large buildings, but we don't. We could guard dams and reservoirs, but we don't. We could inspect sports stadium structural supports for dynamite before major events, but we don't. The high school I attended was recently rebuilt without windows, making its 3,000 students defenseless against poison gases introduced into its ventilation system. Terrorists could easily turn theaters or arenas into blazing infernos with blocked exits, but we don't guard against that. They could kidnap wives and children of Congressmen and other high officials, which might be very effective for their purposes, but we show no concern about that problem.
We are vulnerable to mass murder or blackmail by terrorists on dozens of fronts. All of them would be equally effective and infinitely easier for terrorists to take advantage of than making a bomb from plutonium stolen from the nuclear power industry. Yet there has been a great deal of concern expressed about the latter problem, and none about the others. Actually this may have served a useful purpose. Experts on terrorism have told me that it would be very favorable if terrorists devoted their energies to nuclear terrorism and were thus diverted from the easier and more destructive options available to them.
Another property of plutonium unrelated to its use in bombs has attracted a great deal of attention. That is, its toxicity, as exemplified by Ralph Nader's statement that a pound of plutonium could kill 8 billion people.22 Let's look into that question.
In Chapter 11 we showed how to calculate the toxicity of plutonium ingested into the stomach, which is the way it would most probably enter the human body if it is buried deep underground as part of radioactive waste. However, the most important health effects due to plutonium released from nuclear facilities occur when it becomes suspended in the air as a fine dust and is thereby inhaled into the lungs.*
It is straightforward to quantify the risks associated with this problem. When plutonium oxide, the form in which plutonium would be used in the nuclear industry and also its most toxic form, is inhaled as a fine dust, 25% of it deposits in the lung, 38% deposits in the upper respiratory tract, and the remainder is exhaled.23 Within a few hours, all of that deposited in the upper respiratory tract, but only 40% of that deposited in the lung, is cleared out. The other 60% of the latter (.25 x .60 =) 15% of the total inhaled remains in the lung for a rather long time, an average of 2 years.
From the quantity of plutonium in the lung and the length of time it stays there, it is straightforward to calculate the radiation exposure to the lung in millirems. For example, a trillionth of a pound gives a dose of 1,300 mrem over the 2-year period (see Chapter 13 Appendix). From studies of the Japanese atomic bomb survivors, of miners exposed to radon gas, and other such human exposure experiences, estimates have been developed for the cancer risk per millirem of radiation exposure to the lung (see Chapter 13 Appendix).24,25 Multiplying this by the sum of the radiation doses in millirems received by all those exposed gives the number of cancers expected. The result is that we may eventually expect about 2 million cancers for each pound of plutonium inhaled by people.26,27 (By a more complex process, inhaled plutonium can also cause liver cancer and, to a lesser extent, bone cancer. Our treatment here is thus oversimplified, but the quoted result is correct.)
|Fig. 1 Results of animal experiments with inhaled plutonium. The curved line shows the predictions of the calculation outlined in the text. Data are compiled in ref. 28, and the calculation is explained in detail in ref. 26..|
There is no direct evidence for plutonium-induced cancer in humans, but there have been a number of experiments on dogs, rabbits, rats, and mice. The results of these are summarized28 in Fig. 1, where the curve shows the expectation from our calculation. It is evident that the animal data give strong confirmation for the validity of the calculation.
The 2 million fatalities per pound inhaled leaves plutonium dust far from "the most toxic substance known to man." Biological agents, like botulism toxin or anthrax spores29 are many hundreds or thousands of times more toxic. Plutonium toxicity is similar to that of nerve gas,29 but given the choice of being in a room with equal quantities of plutonium dust and nerve gas, the latter would be infinitely more dangerous. It rapidly permeates the room air, whereas plutonium, being a solid material, would be largely immobile.
In fact, it is rather difficult to disperse plutonium in air as a respirable dust. Individual particles tend to agglomerate into lumps of too large a size to be inhaled. In the experiments on animals, substantial effort and ingenuity was required to overcome this problem30 and arrange for the plutonium dust to be inhaled.
The calculational procedure used here to obtain our result, 2 million deaths per pound inhaled, follows the recommendations of the International Commission on Radiological Protection (ICRP). It would be impossible to obtain a very different result without sharply deviating from them; at least three independent investigations have used them to evaluate the toxicity of plutonium26,27 and they have all obtained essentially the same result. These ICRP recommendations are used by all groups charged with setting health standards all over the world, such as the Environmental Protection Agency and the Occupational Safety and Health Administration in the United States. They are almost universally used in the scientific literature.
Nevertheless, there have been at least two challenges to these procedures. The first was based on the so-called hot-particle theory, according to which particles of plutonium do more damage than if the same amount of plutonium were uniformly distributed over the lung, because the few cells near the particles get much larger radiation doses in the former case. The conventional risk estimates are based on assuming that the cancer risk depends on the average dose to all of the cells in the lung, while the hot-particle theory assumes it depends on the dose to the most heavily exposed cells.
This hot-particle theory had been considered by scientists from time to time over the years, but the issue was brought to a head when the antinuclear activist organization, Natural Resources Defense Council, filed a legal petition asking that the maximum allowable exposures to plutonium be drastically reduced, in view of that theory.31 In response, a number of scientific committees were set up to evaluate the evidence. There were separate committees from the National Academy of Sciences, the National Council for Radiation Protection and Measurements, the British Medical Research Council, and others. All of them independently concluded32 that there is no merit to the hot-particle theory, and that, if anything, concentration of the plutonium into particles is less dangerous than spreading it uniformly over the lung. The scientific evidence is too complex to review here, but a few points are easily understood:
As a result of these studies, the scientific community has rejected the hot-particle theory, and standard-setting bodies have not changed their allowable exposures. However, nuclear power opponents continued to use such widely quoted remarks as "a single particle of plutonium inhaled into the lung will cause cancer."
Shortly after the fuss over the hot-particle theory had cleared away, John Gofman, head of a San Francisco nuclear power opposition organization, proposed34 a new theory of why plutonium should be much more dangerous than estimated by standard procedures. His theory was based on the idea that the cilia (hairs) that clear foreign material from the bronchial regions are destroyed in cigarette smokers, allowing the plutonium to stay there for years rather than being cleared within hours. He ignored direct experiments35 that showed unequivocally that dust is cleared from these regions just as rapidly in smokers as in nonsmokers; apparently, to make up the difference, smokers have more mucous flow and do more coughing. In fact, if smokers cleared dust from their bronchial passages as slowly as Gofman assumes, they would die of suffocation. Because Gofman made errors in his calculation (as in using a surface of the bronchi that was 17 times too small), his paper was negatively critiqued by a number of scientists.36,26 It has never gained any acceptance in the scientific community and has been ignored by all committees of experts and standard-setting groups. I know of no scientist other than Gofman who uses it in his work.
When my paper on plutonium toxicity26 was first published, including its estimate of 2 million cancers per pound of plutonium inhaled, Ralph Nader asked the Nuclear Regulatory Commission to evaluate it. Judging from the number of telephone calls I received asking about calculational details, they did a rather thorough job, and in the end they gave it a "clean bill of health." Nevertheless, Nader continued to state, in his speeches and writings, that a pound of plutonium could kill 8 billion people, 4,000 times my estimate. In fact, he accused me37 of "trying to detoxify plutonium with a pen."
In response, I offered to inhale publicly many times as much plutonium as he said was lethal. At the same time, I made several other offers for inhaling or eating plutonium including to inhale 1,000 particles of plutonium of any size that can be suspended in air, in response to "a single particle . . . will cause cancer, " or to eat as much plutonium as any prominent nuclear critic will eat or drink caffeine. My offers were such as to give me a risk equivalent to that faced by an American soldier in World War II, according to my calculations of plutonium toxicity which followed all generally accepted procedures. These offers were made to all three major TV networks, requesting a few minutes to explain why I was doing it. I feel that I am engaged in a battle for my country's future, and hence should be willing to take as much risk as other soldiers.
None of the TV networks responded (except for a request by CBS for a copy of my paper), so nothing ever came of my offer. However, antinuclear activists have used it to make me seem irrational they say I offered to eat a pound of plutonium, whereas it was actually 800 milligrams, 550 times less. Some people have told me that antinuclear activists get so much media attention because they offer drama and excitement. It seems to me that my offer would have provided these, so there goes another explanation for why the media have been so unbalanced on nuclear power issues.
One story in connection with my offer gives insight into why journalists have performed so poorly in informing the public about radiation hazards. A national correspondent for the Dallas Times Herald quoted me as saying "I offered to inhale a thousand times as much plutonium as [Ralph Nader] would eat caffeine." I wrote a letter complaining about this and a host of other errors in his piece, to which his editor replied in part: "[You wrote] 'I offered to inhale a thousand times as much plutonium as he claims would be lethal, and to eat as much plutonium as he would eat caffeine' . . . this seems to be faithful to what our [correspondent] reported."
It is 5,000 times more dangerous to inhale plutonium than to eat it, and eating plutonium is about equal in danger to eating the same quantity of caffeine. Thus, if I were to do what the writer said I offered to do, I would be taking (1,000 x 5,000 =) 5 million times greater risk than Nader would be taking in eating the caffeine I would surely be dead. Actually I offered to eat (not inhale) the same amount (not 1,000 times as much) of plutonium as he would eat caffeine, giving us equal risks. My offer to inhale plutonium was a completely separate item, intended to point out the ridiculousness of his statements about the dangers of inhaling plutonium. How a national correspondent can interpret my quote as he did, and how an editor can then fail to understand the difference when it is pointed out to him, is beyond my comprehension. Nevertheless, it is people like them, rather than the scientists, who are educating the public about radiation. Note that this is not a question of qualitative versus quantitative; being in error by a factor of 5 million is hardly a matter of lack of precision.
In evaluating the hazards from plutonium toxicity, it gives little insight to say that we can expect 2 million cancers per pound of plutonium inhaled unless we specify how much plutonium would be inhaled in various scenarios. This, of course, depends on the type of release, the wind and other weather conditions, as well as the number of people in the vicinity. But let us say that one pound of plutonium oxide powder gets released in the most effective way in an average big city location under average weather conditions.26 In the hour or so before the wind blows dust out of the densely populated areas, only about 1 part in 100,000 would be inhaled by people,38 enough eventually to cause 19 cancers. If people know about the plutonium, as in a blackmail situation, they could breathe through a folded handkerchief or piece of clothing, which would reduce the eventual death toll from 19 to 3. Better yet, they could go inside buildings and shut off outside air intakes for this critical short time period.
Eventually all of the plutonium dust would settle down to the ground, but there would still be the possibility of its later being resuspended in air by wind or human activities. Its ability to be resuspended is reduced by rain, dew, and other natural processes, as a result of which the principal threat from this process diminishes rapidly over the first year and essentially disappears thereafter.39 All in all, this resuspended plutonium dust eventually causes about seven deaths.
Within a few years the plutonium works its way downward into the ground, becoming a permanent part of the top layers of soil. As is well known, it remains radioactive for a very long time. How much harm it does over that period depends on its probability of getting suspended in air by plowing, construction, or natural processes, and then being inhaled by humans. Due to these processes, an average atom of a heavy metal in the top eight inches of soil has 13 chances in a billion of being inhaled by a human each year.26 If this probability is applied to the plutonium, it will cause a total of only 0.2 additional deaths over the tens of thousands of years that it remains radioactive.
During this period, plutonium in the soil can also be picked up by plant roots, thereby getting into food. This process has been studied in many controlled experiments and in various contamination situations such as bomb test sites and waste disposal areas.40 Its probability is highly variable with geography, but even under the most unfavorable conditions, this would lead to less than one additional fatality over the tens of thousands of years.
In summary, a pound of plutonium dispersed in a large city in the most effective way would cause an average of 19 deaths due to inhaling from the dust cloud during the first hour or so, with 7 additional deaths due to resuspension during the first year, and perhaps 1 more death over the remaining tens of thousands of years it remains in the top layers of soil. This gives and ultimate total of 27 eventual fatalities per pound of plutonium dispersed.26
It has often been suggested that plutonium dispersion might be used as an instrument for terrorism. But this is hardly realistic because none of the fatalities would occur for at least 10 years,* and most would be delayed 20 to 40 years. It could not be used for blackmail because if the dispersal is recognized, protective action is easily taken breathing through handkerchiefs, or going indoors. Terrorists would do much better with nerve gas, which can be made from readily available chemicals; it leaves dead bodies at the scene.
There have been fears expressed that we might contaminate the world with plutonium. However, a simple calculation show26 that even if all the world's electric power were generated by plutonium-fueled reactors, and all of the plutonium ended up in the top layers of soil, it would not nearly double the radioactivity already there from natural sources, adding only a tiny fraction of 1% to the health hazard from that radioactivity. As is evident from the previous discussion, plutonium in the ground is not very dangerous, because there is no efficient mechanism for transforming it into airborne dust.
John Gofman, the opponent of nuclear power whose work has been discussed previously, has been speaking and writing about effects of plutonium toxicity on the basis of what he calls 99.99% containment.41 By this he means that 0.01% of all plutonium used each year will be released as a respirable dust that will remain suspended in air for long time periods. It turns out that even the steel and asphalt industries do better than that in containing their products,42 often holding respirable dust releases down to 0.001%. But in plutonium handling, releases are very much smaller. Let's consider the reasons for this.
In the steel and asphalt industries, the materials are heated far above the melting point, resulting in vigorous boiling, which is a prime mechanism for converting some of the material into airborne dust; in the nuclear power industry, plutonium would not normally be heated to its melting temperature. During processing, steel and asphalt are handled in open containers, well exposed to the building atmosphere, whereas plutonium is always tightly enclosed and completely isolated from the building atmosphere. The air from the building atmosphere can mix with outside air only after passing through filters. In steel and asphalt plants these filters consist of ordinary fabric, whereas in plutonium plants they are specially developed high-efficiency filters capable of removing 99.9999% of the dust from air passing through them.
Current Environmental Protection Agency (EPA) regulations require that no more than about one part in a billion of the plutonium handled by a plant escape as airborne dust.43 All plants now operate in compliance with that regulation. It is 100,000 times less than the releases Gofman has been assuming. If all of the electricity now used in the United States were derived from breeder reactors, the maximum allowable releases would be 0.0007 pounds per year. If all plants were in large cities, where we have shown that plutonium releases cause 27 deaths per pound, this would correspond to one fatality every 50 years somewhere in the United States. Since these facilities would not be in cities, the consequences would be considerably lower, much less than one death per century.
Of course, the EPA regulations do not cover releases in accidents, and there have been some of these. Two of the most notable were fires in a Rocky Flats, Colorado, plant for fabrication of parts for bombs, where plutonium is handled in a flammable form (the forms used in the nuclear power industry are not flammable).44 In the earlier fire in 1957, about 1 part in 300,000 .002 ounces of the plutonium that burned escaped as dust.* After that, many improvements were made, so that in the much larger fire in 1969, only 1 part in 30 million of the plutonium that burned escaped. Safety analyses indicate that new improvements will considerably reduce even this low figure.
Since only a tiny fraction of all plutonium handled each year would be involved in fires or other accidents, much less than one-billionth of the total would be released. Thus, accidents are a much lesser source of plutonium in the environment than the routine releases which are covered by the EPA regulations, and the total impact of plutonium toxicity in a full breeder reactor electricity system would be less than one death per century in the United States.
The most important effects of plutonium toxicity by far are those due to nuclear bombs exploded in the atmosphere. Only about 20% of the plutonium in a bomb is consumed, while the rest is vaporized and floats around in the Earth's atmosphere as a fine dust. Over 10,000 pounds of plutonium has been released in that fashion by bomb tests to date,44 enough to cause about 4,000 deaths worldwide. Note that the quantity already dispersed by bomb tests is more than 10 million times larger than the annual releases allowed by EPA regulations from an all breeder reactor electric power industry.
I am often asked why such tight regulations are imposed on plutonium releases if they involve so little danger. The answer is that government regulators are driven much less by actual dangers than by public concern. They do pay attention to technological practicalities, and it turns out not to be too difficult to achieve very low releases. Costs are taken into account, but all plutonium handling is now in the military program, where cost is not such an important factor. The guiding rule for regulators is that all exposure to radiation should be kept "As Low As Reasonably Achievable" (ALARA), and in the case of plutonium releases the regulation cited corresponds to EPA's judgement of what is ALARA.
The difficulty with this system is that the public interprets very elaborate safety measures as indicators of great potential danger. This increases public concern and perpetuates what has become a vicious cycle involving all aspects of radiation protection the more we protect, the greater the public concern; and the greater the public concern, the more we must protect.
One often hears that in large-scale use of plutonium we will be creating unprecedented quantities of poisonous material. Since plutonium is dangerous principally if inhaled, it should be compared with other materials which are dangerous to inhale. If all of our electricity were derived from breeder reactors, we would produce enough plutonium each year to kill a half trillion people.* But as has been noted previously in Chapter 5, every year we now produce enough chlorine gas to kill 400 trillion people, enough phosgene to kill 18 trillion, and enough ammonia and hydrogen cyanide to kill 6 trillion with each. It should be noted that these materials are gases that disperse naturally into the air if released, whereas plutonium is a solid that is quite difficult to disperse even intentionally. Of course, plutonium released into the environment will last far longer than these gases, but recall that the majority of the harm done by plutonium dispersal into the environment is due to inhalation within the first hour or so after it is released. The long-lasting nature of plutonium, therefore, is not an important factor in the comparisons under discussion.
One final point about plutonium toxicity that should be kept in mind is that all its effects on human health that we have been discussing are theoretical. There is no direct evidence or epidemiological evidence, that the toxicity of plutonium has ever caused a human death anywhere in the world.
I have been closely associated professionally with questions of plutonium toxicity for several years, and the one thing that mystifies me is why the antinuclear movement has devoted so much energy to trying to convince the public that it is an important public health hazard. Those with scientific background among them must realize that it is a phony issue. There is nothing in the scientific literature to support their claims. There is nothing scientifically special about plutonium that would make it more toxic than many other radioactive elements. Its long half life makes it less dangerous rather than more dangerous, as is often implied; each radioactive atom can shoot off only one salvo of radiation, so, for example, if half of them do so within 25 years, as for a material with a 25-year half life, there is a thousand times more radiation per minute than emissions spread over 25,000 years, as in the case of plutonium.
No other element has had its behavior so carefully studied, with innumerable animal and plant experiments, copious chemical research, careful observation of exposed humans, environmental monitoring of fallout from bomb tests, and so on. Lack of information can therefore hardly be an issue. I can only conclude that the campaign to frighten the public about plutonium toxicity must be political to the core. Considering the fact that plutonium toxicity is a strictly scientific question, this is a most reprehensible situation.
I am convinced that the public has bought the propaganda about the dangers from plutonium toxicity. Ask a layperson; he or she will probably tell you that plutonium is one of the most toxic substances known and is a terrible threat to our health if it becomes widely used. The media accept this as fact; plutonium toxicity is no longer treated as an issue worthy of their attention. The deception of the American people on this matter is essentially complete. Lincoln was wrong when he said "you can't fool all the people all the time."
PuO2, dogs, J. F. Park, private communication to R. C. Thompson quoted in BNWL-SA-4911.
PuO2, mice, L. A. Temple et al., Nature 183, 498 (1959).
PuO2, mice, L. A. Temple et al., Nature 183, 498 (1959).
PuO2, mice, R. W. Wagner et al., Hanford Report HW-41500 (1956).
Pu, citrate, rats, L. A. Buldakov and E. R. Lyubchanskii, translation in ANL-tr-864 (1970), p. 381.
Pu pentacarbonate, rats, L. A. Buldakov and E. R. Lyubchanskii, translation in ANL-tr-864 (1970), p. 381.
Pu nitrate, rats, R. A. Erokhim et al., translation in AEC-tr-7387 1971), p. 344.
Pu nitrate, rabbits, N. A. Koshurnikova, translation in AEC-tr-7387 (1971), p. 334.
Pu pentacarbonate, rabbits, N. A. Koshurnikova, translation in AEC-tr-7387 (1971), p. 334.
CHAPTER 13 APPENDIX
Fraction of Cost of Nuclear Power due to Raw Fuel
Nuclear fuel undergoing fission produces 33 x 106 kW-days45 of heat energy per metric ton (2,200 lbs). It requires about 6 tons of uranium to make 1 ton of fuel,* and one-third of the heat energy is converted into electricity.45 Therefore, the electrical energy per pound of uranium is
|1/3 x 33 x 106 kW-days|
6 x 2,200 lb
Nuclear electricity costs about 7 cents/kW-hr, so the electricity production from one pound of uranium costs (.07 x 20,000 =) $1,400. Uranium costs about $25/lb, which is 2% of this cost.
Cost of Gasoline versus Cost of Nuclear Fuel
From straightforward energy conversions, 1 pound of nuclear fuel undergoing fission is equivalent to 2.5 x 105 gallons of gasoline. Since the energy conversion efficiency in a breeder reactor45 is 40%, the electrical energy from 1 pound of uranium, which costs about $25, is equal to that in 1.0 x 105 gallons. The equivalent cost of gasoline is therefore ($25/1 x 105 gallon =) .025 cents/gallon. This is 40 gallons for a penny.
Present reactors burn only 1% of the uranium and are only 33% efficient, so the fuel cost is higher by a factor of (100 x 40/33 =) 120. This is equivalent to gasoline costing (120 x .025 =) 3 cents/gallon.
Radiation Dose to Lung from Plutonium and the Lung Cancer Risk
This calculation requires knowing (or accepting) some scientific definitions and may therefore not be understandable to many readers.
We calculate the dose to the lung from a trillionth of a pound of plutonium residing there for 2 years. The number of plutonium atoms is 10-12 lb x 450 g/lb x (6 x 1023 atoms/239 gm) = 1.1 x 1012 where 6 x 1023 is Avogadro's number and 239 is the atomic weight.45 Since half of the plutonium atoms will decay in 24,000 years (the half life), the fraction undergoing decay during the 2 years it spends in the lung is a little more than one in 24,000; actually it is 1/17,000. The number that decay is then (1.1 x 1012/17,000 =) 7 x 107. Each decay releases an energy of about (5 MeV x 1.6 x 10-13 joules/MeV =) 8 x 10-13 joules, so the total radiation energy deposited is (7 x 107 x 8 x 10-13 =) 5.6 x 10-5 joules.45 The weight of the average person's lung is 0.57 kg46; thus the energy deposited is (5.6 x 10-5 / 0.57 =) 1 x 10-4 joules/kg. The definition of a millirad45 is 1 x 10-5 joules of energy deposit per kg of tissue.* The dose is therefore (1 x 10-4 / 1 x 10-5 =) 10 millirad. Since only 15% on what is inhaled spends this 2 years in the lung,23 the exposure per trillionth of a pound inhaled is (10 x 0.15 =) 1.5 millirad. For alpha particles the radiation emitted by plutonium 1 millirad equals 20 millirem,47 so the dose to the lung is (1.5 x 20 =) 30 millirem per trillionth of a pound inhaled.
Estimates by BEIR,24 UNSCEAR,25 and ICRP47 give a risk of about 5 x 10 -7 lung cancers per millirad of alpha particle exposure. The number of lung cancers per pound inhaled is therefore (1.5 x 1012 x 5 x 10-7 =) 8 x 105. Mays27 estimates 4 x 105 liver and bone cancers per pound inhaled, bringing the total effect to 1.2 million cancers of all types per pound inhaled.
There are two factors modifying this estimate. One is that this calculation is for young adults; averaging over all ages reduces the risk by half. The other factor is due to the fact that our calculation was for Pu-239, whereas typical samples of plutonium contain a mixture of other isotopes that generally contain more radioactivity per pound because they have shorter half lives.
When these factors are taken into account,26 the deaths per pound inhaled become 4.2 million for wastes from present reactors, 2.7 million for breeder reactor fuel, and 0.8 million for weapons plutonium. In this chapter we have used 2 million deaths per pound as a loose average, mainly because than number has been used in most studies whose results are quoted here. All results quoted can be adjusted by taking effects to be proportional to these numbers.