If it is to benefit humanity, concern for our planet and the future of our civilization needs to be matched with an understanding of the facts. High among such apprehensions should be the potential of destruction of populations and the entire fabric of organized society by the use of the existing arsenals of nuclear weapons in Russia, the United States, and other countries. A second worry is the plundering of the planet for carbon-based energy, with the accompanying increase in atmospheric carbon dioxide and the resulting rise in world temperature. Our purpose in this book is to provide sound information for resolving the conundrum of control of nuclear weaponry and for providing acceptable energy for the future, whether or not society uses nuclear power.
Nuclear energy burst on the world in August 1945 with the explosion of atomic bombs over the Japanese cities of Hiroshima and Nagasaki. Never since employed in warfare, nuclear weapons have nevertheless played an enormous role in U.S. national security. With an overall cost of about $4 trillion for the weapons, their command and control, and their delivery systems, they are regarded by some as having prevented a third world war for more than 50 years. Others believe that they have created an unparalleled hazard for the United States and for the world. Perhaps both views are correct.
Soon after the Second World War, nuclear energy was applied to less destructive purposes, in the propulsion of submarines and naval surface ships, as well as icebreakers. For the first time, the United States (and soon thereafter the Soviet Union and then Britain and France) had a true submarine--one that could travel submerged for months, capable of destroying shipping or preventing its passage, threatening opposing naval forces, or launching strategic ballistic missiles to destroy cities or military targets.
In parallel with the mastery of nuclear energy for warfare arose the nuclear power industry. Under normal circumstances, more than 430 large commercial reactors now provide almost 20% of the world's electrical power--the equivalent of 340 plants of a million kilowatts of electricity, each of which could serve an American city of nearly one million. In France, 80% of the electrical power comes from nuclear facilities.
This book first provides the background of the mastery of the release of nuclear energy over the past sixty years--explosively in weapons, and more gradually in nuclear reactors producing heat and electricity. Next there is a section on the technology and evolution of nuclear weaponry--simpler in principle than power reactors--followed by a chapter on the fundamentals and implications of the impact of nuclear radiation on health, which is of importance both in nuclear weaponry and in nuclear power. Then comes a section on nuclear reactors, their common features and their variants, as well as on experience in the supply of nuclear electricity. Following a discussion of the long-term energy future, the book ends with a view of the policy options for managing the world's nuclear weaponry and for obtaining the benefits of nuclear power at tolerable cost and risk.
Nuclear Weapons. The first nuclear weapons had an energy yield equivalent to about 20,000 tons of a powerful explosive (TNT)--20 "kilotons," or 0.02 "megaton." A typical strategic weapon now has a yield of 0.5 megaton. The number of U.S. nuclear devices grew to a peak of 33,000 in 1967 and is now about 12,000. The Soviet Union had some 45,000 nuclear weapons available in 1986, and Russia now has perhaps 18,000. For years, the push of a button in Moscow would have ensured the destruction of the United States and of Western Europe by a Soviet Union that was in turn threatened with devastation by the more accurate U.S. weapons.
A decade after the end of the Cold War, U.S. and Russian nuclear arsenals remain ready for use. The use of a mere 20 weapons would kill 25 million people in the United States or Russia. In the United States, the political debate focuses on absolute security against the explosion on American soil of even a single weapon from some new ("rogue") nuclear state--perhaps North Korea, Iraq, or Iran. With the evolution and diffusion of industrial technology over the last half century, accelerated by the Internet revolution, the barriers to the acquisition of nuclear weapons are primarily political; but there also remains the requirement of obtaining materials like plutonium or enriched uranium.
Nuclear Power. The generation of electricity from nuclear reactors is a mature industry with potential for further technological innovation. The importance of nuclear power, however, has a dimension beyond the question of price and operating risk. Over the last 20 years, the scientific understanding of climate has led to the conclusion that the continued increase in carbon dioxide in the atmosphere (largely from the burning of fossil fuels--coal, oil, and gas) can transform the earth's climate, causing great human and economic losses. Whether this "enhanced greenhouse effect" is already reflected in the fact that the 1990s were the warmest decade (and 1998 the warmest year) in recorded human history is still debated by some. Nevertheless, the nations of the world, meeting at the Conference of the Parties of the United Nations Framework Convention on Climate Change in Kyoto in 1997, agreed that by the year 2010 or 2012 the industrialized countries should reduce their overall carbon emissions--more precisely, their carbon-dioxide-equivalent emissions--by at least 5% below the 1990 level, despite the continued growth in population and industrial output. Even if these goals are met, atmospheric carbon dioxide will still increase in absolute terms.
If the level of carbon dioxide in the atmosphere (and its equivalent from other "greenhouse gases") were to be held only to a doubling of the preindustrial level--i.e., that of 1850--more than half the world's energy would need to come from noncarbon sources1 by the year 2050.
Nuclear energy can fill part of this gap, but only if there are assured
- availability of nuclear fuel,
- safety against catastrophic accident,
- management and disposal of nuclear waste, and
- affordable cost.
In contrast to the preponderance of nuclear power in France (and the many reactors built in Japan and Korea in recent decades), not a single reactor built in the United States was ordered after 1973, Sweden is committed to the elimination of nuclear power, and Germany agreed in June 2000 with its nuclear industry to close reactors over the next 20 years--more specifically, after producing an amount of electrical energy equivalent to an average working life of 32 years for each nuclear plant.
The Link Between Nuclear Weapons and Nuclear Power. The materials that produce heat in nuclear power plants--uranium and plutonium--can be used more and more readily to make nuclear weapons. The number of nations and groups in the world capable of fabricating nuclear devices has increased greatly with the diffusion of technology, so that the real barrier--once the decision to build nuclear weapons has been made--is the availability of plutonium or uranium. Since the 1950s, the expansion of nuclear power in states not possessing nuclear weapons has been undertaken with an emphasis on strict controls preventing the diversion of civilian materials into military armories, but these controls consist mainly in accounting and do not of themselves constitute a true security system.
Something New: Megatons to Megawatts. Even before the end of the Cold War and the dissolution of the Soviet Union, that nation and the United States (with more than a hundred times as many nuclear weapons as the rest of the world combined) had undertaken bilateral agreements to limit and reduce their nuclear weaponry. In 1993 the United States contracted to buy 500 tons of weapon uranium from Russia, its 90% enrichment in U-235 so reduced (to about 5%) that it is useful in nuclear reactors and impossible to use directly in weapons. Over 20 years, $12 billion is to be transferred for the acquisition of material from more than 10,000 disassembled weapons. In 1998, the United States and Russia agreed that each would declare 50 tons of weapon plutonium excess and transfer it out from the military sector, either for disposal as waste or for burning in reactors. This quantity corresponds to plutonium from about 20,000 weapons. The Russian uranium purchased by the U.S. side is handled by the recently privatized (July 1998) United States Enrichment Corporation; the program goes by the name "Megatons to Megawatts." In fact, a megaton of explosive energy release corresponds to the heat produced in about 20 days of operation of a plant supplying 1000 megawatts of electricity--thus 20,000 megawatt-days.
One of the major controversies concerning the future of nuclear power is the near-term employment of plutonium, with one extreme position consisting in rejecting the use of nuclear reactors to burn plutonium from excess nuclear weapons (a "Megatons to Megawatts" approach), while another insists that plutonium produced in the normal operation of civilian power plants should always be separated and recycled in those reactors rather than disposed of as "waste."
In this book we introduce the tools for understanding both nuclear weaponry and nuclear power, highlighting the options available, those under investigation, and the decisions that must be taken to reduce the threat of nuclear weapons. We analyze the prerequisites for the expansion of nuclear power that would have to be met if it is to make a substantial contribution to limiting the warming of the earth by enhanced greenhouse effect.
Making the wrong decisions in nuclear weaponry and nuclear power can greatly imperil the security of the United States and, indeed, of the entire world. Right decisions may provide the tools that can supply clean energy for millennia. Although we do not hesitate to draw conclusions from our analysis, we encourage interested readers to reach their own. We begin with a clarification of the nature of energy and of nuclear fission--the genie that poses both such peril and such promise.
Excerpted from Megawatts and Megatons by
Richard L. Garwin and Georges Charpak
Copyright 2001 by Richard L. Garwin and Georges Charpak. Excerpted by
permission of Knopf,
a division of Random House LLC. All rights reserved. No part of this excerpt
may be reproduced or reprinted without permission in writing from the publisher.