Many people claim that they oppose nuclear power plants because they threaten "the ecology." Trained ecologists, however, often tend to take a different view. The scientists, you see, know that natural ecosystems are quite resilient in the face of increased levels of radioactivity. In fact, such living communities are actually more resistant to radiation than they are to the acid rains that result from the combustion of fossil fuels!
Therefore, from the point of view of the health of the ecosystem—rather than the health of people—nuclear power could be one of our more desirable energy options. It could, that is, except that the weapons connection must also be considered. Unfortunately, the spread of nuclear power plants is intimately connected with the spread of atomic bombs ... called "nuclear proliferation" in current jargon. And atomic warfare, of course, is good for neither people nor ecosystems.
How It Works
It is a sad fact that the knowledge required to build an atomic bomb is very widespread. Credible explosive devices have been designed by college physics students, and—in at least one case—by a high school boy! The basic idea is first to assemble a large enough mass of fissile material (uranium 233 or 235, or plutonium 239) and then hold it together long enough for a nuclear explosion to occur.
U-233, U-235, and P-239 nuclei undergo spontaneous splitting—fissioning—accompanied by the release of both energy and neutrons. If a neutron from a fissioning nucleus is "captured" by another fissile nucleus, it will fission, too ... and release more energy and neutrons. When there are just enough other nuclei around to serve as targets so that a self-sustaining chain reaction occurs, there's said to be a critical mass. With proper controls, the heat from such a chain reaction can be used to make steam in a nuclear power plant.
If there are more than enough target nuclei around, though, the mass is said to be supercritical ... and the chain reaction will escalate with extreme rapidity. And if such a situation persists (a small fraction of a second is enough), it will produce the well-known fireball, followed by the mushroom-shaped cloud.
There are two basic weapons-design techniques for reaching supercriticality. The first involves bringing two subcritical masses together very rapidly. In the bomb dropped on Hiroshima, for example, a subcritical chunk of U-235 was fired into the center of another subcritical chunk by a small cannon. The Hiroshima weapon was thus called a "gun-type" bomb.
The second route to supercriticality requires that a subcritical mass be compressed so that the nuclear targets of the neutrons are crammed closer together, thus ensuring that a higher proportion of the neutrons will be captured. Compression is achieved by surrounding a subcritical mass with conventional explosives, which are detonated simultaneously. The squeeze comes from the "implosion." Such a contraption, using P-239, did away with Nagasaki. The design is called an "implosion-type" bomb.
There are, of course, technical problems that must be overcome in order to get such bombs to work properly: One must, for instance, prevent premature ignition (which would blow a gun-type bomb apart before much of its energy could be released), and determine the exact arrangement of the explosives in an implosion-type bomb. Unfortunately, it now appears that crude but workable bombs can be made by following designs that are simpler than those of either gun or implosion devices.
Power Plants and Proliferation
The fact is that the basics of atomic bomb design had already been pretty well worked out by the early 1940's. Then, as now, the crucial problem encountered in creating such a device was that of obtaining enough fissile material. (Even the famed Manhattan Project was not primarily a bomb-designing operation. Its work was focused on finding ways to produce enough U-235 and P239 to make nuclear weapons.)
Nuclear power plants, alas, solve the problem of producing fissile material for bombs. Between 4 and 9 kilograms (9 to 20 pounds) of plutonium 239 and uranium 233—and 11 to 25 kilograms (24 to 55 pounds) of uranium 235—are required to make a bomb. For comparison, more than 200 kilograms of plutonium or uranium 233 leave the reactor (in spent fuel rods) of a 1,000-megawatt, commercial nuclear power plant annually.
Worse yet, all varieties of nuclear power reactors produce fissile materials suitable for bomb making, which means that any nation with nuclear reactors has a ready source of the basic ingredients needed to produce atomic bombs. Thus it seems that the spread of nuclear power plants around the globe is destined to carry along with it the spread of nuclear weapons capability ... to nation after nation.
This threat has been recognized by the international community, whose chief response has been the Nonproliferation Treaty of 1968. Regrettably, many key nations (such as South Africa and Brazil, both countries that are at least close to becoming nuclear powers) have not signed it.
Then too, the agency designated to administer the treaty, the International Atomic Energy Agency (IAEA), might or might not be able to detect a government's clandestine diversion of fissile material from the nuclear fuel cycle ... and furthermore, the agency has no effective way of stopping such diversion even if it were detected.
Nuclear proliferation is, of course, already well underway. India has detonated its first atomic bomb. (The Indians conducted the "test" at a time of food shortage and announced—in essence—that other nations which were bargaining with them about food and fertilizer were now dealing with a nuclear power.) Pakistan has since made no bones about its desire to add A-bombs to its inventory of weapons.
Israel has long been suspected of having a nuclear arsenal, and its opponents—including the Soviet Union—have clearly had to take that possibility into consideration ... especially since Israel also has sophisticated delivery systems. Many people think that South Africa, with Israel's help, has also become a nuclear power ... or quickly could do so. Brazil, with the assistance of West Germany, may be well on its way to atomic bomb production, too.
A Terrible Problem
As the number of nuclear power plants multiplies around the globe, our concern must go beyond proliferation among governments as we face the frightening possibility of proliferation among subnational terrorist groups. If there were only 1,000 large nuclear plants worldwide (today there are already over 200 in existence), the annual flow of fissile material from the plants would be in the vicinity of a quarter of a million kilograms ... and the nuclear industry has never shown itself capable of keeping track of more than 99% of the fissile material in the system. At best, therefore, in a 1,000-plant economy the MUF (Material Unaccounted For) each year would amount to some 2,500 kilograms ... enough, conservatively, to build 100 atomic bombs.
The problem of permanently preventing the diversion of some of the MUF from plutonium or uranium recycling by well-financed terrorist groups is virtually impossible to solve. The industry's record of control, so far, has been terrible. (In fact, the Israelis are thought to have obtained some of the fissile material for their bombs by diverting it from the United States.)
Threats by terrorists to detonate atomic bombs in American cities are already almost commonplace: Over 50 have been made since 1970. Of these, four were sufficiently credible to generate considerable official concern. During the most alarming instance (in November of 1975), the government's NEST (Nuclear Emergency Search Team) was called in to scout parts of Los Angeles for an atomic device. And, in one of the few such incidents that have been publicized, a credible blackmail threat (including a bomb design and a sample of uranium) was mounted against Orlando, Florida by a 14-year-old boy.
It is certainly not pleasant to contemplate a world in which virtually all governments and many subnational groups possess or have access to nuclear weapons. And recent events make that vision appear even more unpleasant. A national magazine has published key aspects of the secret of how to convert an atomic (fission) bomb into a hydrogen (fusion) bomb. The information will simplify the task of governments, previously stymied by an extraordinarily difficult design problem, to upgrade their A-bombs into H-bombs ... weapons with hundreds of thousands of times more destructive power than the former devices have. We can be grateful that the process is too complex to be accomplished by run-of-the-mill terrorists (even building A-bombs is tricky and dangerous), although this is, of course, small consolation.
We Could Buy Time
But, you say, isn't the cat already out of the bag? Isn't it now inevitable that virtually all nations will become nuclear powers, regardless of any future decisions made about nuclear power plants? Isn't it—then—just a matter of time before part of a city such as New York, Denver, or San Francisco is destroyed ... with all the accompanying horrors of death, radiation sickness, cancer, and permanent contamination?
Well, you're probably correct, but the big question is "how soon?" If the United States, for example, should turn away from the nuclear power option, the move might well tip the balance against nukes in other Western nations. It would certainly have a dampening effect on worldwide nuclear proliferation ... and it would buy some time.
Time is a precious commodity in the nuclear age. Time must be found for politicians to work out nonviolent ways of solving international disputes. And time must be found to erase the incentives that lead to acts of terrorism, or at least to persuade nations to accept a "once-through" nuclear fuel cycle from which terrorist diversion of materials would be almost impossible.
The U.S. government already has plans for suspension of civil liberties—and the establishment of a nuclear police state—as its response to the expected increase in atomic blackmail. And who would deny it the power, if the alternative involves the vaporization of entire chunks of cities?
Buying more time may seem a dim hope in a world apparently poised on the brink of nuclear war—a world in which threats of nuclear terrorism have already become commonplace—but it may be the only hope we have. As a reporter who recently summarized the world terrorism situation put it: "Nuclear technology is out of control. Any sane government policy must be founded on that central fact."
An overview of the problem of proliferation may be found an pages 453-456 of Ecoscience: Population, Resources, Environment by Paul R. Ehrlich, Anne H. Ehrlich, and John P. Holdren (W. H. Freeman and Company). An excellent description of the ease with which a clandestine A-bomb can be built appeared in John McPhee's The Curve of Binding Energy (Farrar, Straus & Giroux, 1974). A description of some recent acts of terrorism and government responses were published in a superb article, "Nuclear Nightmare", by Michael Singer and David Weir, in the December 3, 1979 issue of New West magazine.
In December 1981 Anne and Paul Ehrlich, and their friend and co-author John Holdren, will join MOTHER for a unique South Pacific Seminar on the idyllic islands of Bora Bora and Raiatea.
Paul Ehrlich (Bing Professor of Population Studies and
Professor of Biological Sciences, Stanford University) and
Anne Ehrlich (Senior Research Associate, Department of
Biological Sciences, Stanford) are familiar names to
ecologists and environmentalists everywhere. As well they
should be. Because it was Paul and Anne who—through
their writing and research—gave special meaning to
the words "population", "resources", and "environment" in
the late 1960's. (They also coined the term coevolution, and did a lot to make ecology the household word
it is today.) But while most folks are aware of the
Ehrlichs' popular writing in the areas of ecology and
overpopulation (most of us—for instance—have
read Paul's book The Population Bomb) . . . far too few
people have any idea of how deeply the Ehrlichs are
involved in ecological research (research of the type that
tends to be published only in technical journals and
college textbooks). That's why it pleases us to be able to
present—on a regular basis—these
semi-technical columns by authors/ecologists/educators Anne
and Paul Ehrlich.