<h2>Opportunities and challenges for the next century</h2>
In last week's Inside Story I wrote a tribute to the Manhattan Project pioneers on the occasion of the 50th anniversary of the Trinity test. On Sunday, July 16, I had the pleasure of participating in a panel discussion at the "Symposium on the 50th Anniversary of the Trinity Test" in Washington, D.C., sponsored by the National Academy and the Department of Energy. <p>
The symposium provided an excellent forum to thank the pioneers for their contribution to world peace and to science. Secretary O'Leary and Senator Bingaman gave excellent keynote speeches, and Harold Agnew was terrific. I want to share with you my thoughts that formed the basis for my opening remarks at the symposium. A video of the full symposium will be available soon on LABNET.<p>

<h3>Trinity: Opportunities and challenges for the next century</h3>
First, I want to pay tribute to the Manhattan Project pioneers, many of whom are here today, for their remarkable accomplishment. I want to repeat a tribute that Richard Rhodes, the author of "The Making of the Atomic Bomb," paid at the 50th anniversary of the founding of the Los Alamos Laboratory two years ago: "You changed the world irrevocably, and short of the destruction of human memory, there will be no changing it back. I believe that world owes you and those of your colleagues who are now gone an immense debt of gratitude."<p>

<h3>Scientific opportunities</h3>
We were asked to address the challenges and opportunities as we enter the 21st century, but very little has been said at today's symposium about future scientific opportunities. In addition to changing the global security picture forever, the Manhattan Project also ushered in an era of unprecedented impact of science on human lives. The Manhattan Project demonstrated how fundamental science, combined with large-scale engineering, can solve major problems of national importance and can affect our lives profoundly. It also created a spirit that scientists and engineers working together in groups toward a common objective using a scientific approach can conquer the most difficult problems facing mankind. This spirit set the stage for a half century of unprecedented scientific and technological progress.<p>
Fifty years ago, it was predominantly physics that was combined with a practical understanding of materials and with engineering to build the bomb. Today, it is also molecular biology that is ripe to be integrated with engineering to provide a better understanding of diseases and how to design cures on a molecular basis. We have also developed an atomistic understanding of materials that allows us to tailor-make new materials one atom layer at a time leading to breakthroughs for new engineering applications such as the high-temperature superconductors just developed at Los Alamos. Even after 50 years, we have only scratched the surface of what science can do. <p>

<h3>Security challenges</h3>
I believe that the Manhattan Project shaped the world in a positive way. It helped end quickly a most cruel war. J. Robert Oppenheimer said "The atomic bomb was the turn of the screw. It has made the prospect of future war unendurable." He was right. These weapons have not been used since 1945, making the Manhattan Project turn out all right. Our challenge is to extend that success over the next 50 years.<p>
First, we must find a way to reduce the nuclear arsenals as rapidly as possible and to the smallest possible number of weapons, without making the world safe for massive conventional warfare, such as that which led to 55 million deaths during World War II. To do so, the United States must remain strong and be resolved to play a special international role. Since nuclear weapons are the only weapons that can threaten the very existence of mankind, the United States must keep its weapons safe, secure and reliable, and it must be able to retain its confidence in these weapons. <p>
In today's world, confidence must be maintained without nuclear testing, without a continuous cycle of new weapons replacements, and with smaller defense budgets. We can accomplish this only by increasing our fundamental understanding of weapons phenomena -- what we call science-based stockpile stewardship. I believe that the United States can manage with fewer nuclear weapons; but we cannot afford to be less smart. The key to nuclear weapons stockpile stewardship will be smart stewards. <p>
Second, we must stop the proliferation of nuclear weapons. We face the immediate challenge of keeping nuclear weapons out of the wrong hands -- a challenge that has a high profile and immediacy with players such as Iraq, Iran and North Korea. However, we face the even more daunting longer-range challenge of preventing the massive arming or rearming of nations. This means not only Russia and China, but nations such as Germany, Japan, South Korea, India and every other advanced technological country in the world. Such proliferation could once again threaten the existence of mankind.<p>
The key in controlling nuclear proliferation is controlling weapons-usable fissile materials. If you have plutonium or highly enriched uranium, you can build a bomb. If you have lots of such fissile materials, you can build lots of bombs. The trouble is, there is lots of fissile material in the world today, and the amount is growing. I will concentrate on plutonium since highly enriched uranium can be readily blended to make it unattractive for bombs.<p>
The United States and Russia are believed to possess more than 200 metric tons of weapons-grade plutonium. Civilian power plants around the world have produced close to 1,000 metric tons of plutonium. Much of the plutonium is in spent fuel and is therefore quite unattractive for now; but much has been reprocessed and constitutes weapons-usable material. Furthermore, while reprocessing requires specialized equipment and must deal with the dangers of high levels of radioactivity, it is not a significant deterrent for a determined proliferator. The overall civilian inventory of plutonium is growing at a rate of approximately 70 metric tons per year. Some have estimated that in 30 to 40 years there may exist sufficient plutonium in the world for one million bombs. <p>
A long-term solution to this dilemma will tax world diplomacy and science and technology as much as the Cold War did for the past 50 years. The energy needs and the role that nuclear power plays differ substantially from country to country resulting in very different philosophies for plutonium disposition. I view this as a great opportunity for science and technology to offer new solutions to this dilemma. <p>
Scientists could help to develop a roadmap for dealing with the plutonium legacy, beginning with the surplus weapons-grade material. The four key steps are stabilize, secure, store and dispose.<p>
We must stabilize plutonium existing in various process and storage facilities around the country. Currently, the plutonium exists not only in returning warheads but also in production residues at Rocky Flats, Hanford and Savannah River, as well as in nuclear waste. This situation represents a significant environmental, safety and health challenge in the United States and a similar challenge in Russia and the states of the former Soviet Union.<p>
We must secure plutonium to protect it from diversion for unauthorized use. This is an urgent problem in Russia where safeguards were provided by guns, guards and fences. These safeguards have eroded with the dissolution of the Soviet Union. They must now be replaced with modern inventory techniques and nuclear technologies that will provide an adequate safeguard for the materials in the former Soviet Union. The Department of Energy has sponsored a lab-to-lab technology-based program that is introducing such techniques through cooperative efforts between its laboratories and the Russian nuclear weapons institutes. <p>
We must be able to store fissile materials safely (perhaps for many decades) with adequate security and to allow for international inspection. Safeguards should include substantial barriers to make storage as terrorist-proof as possible. <p>
Eventually we must be able to dispose of fissile materials in a way that is economically attractive, environmentally acceptable and that minimizes opportunities for diversion. Since fissile materials have energy contents many millions of times that of fossil fuels, many nations will find it attractive to recover the energy from fissile materials. The economics of "burning" fissile materials with today's technologies are being seriously questioned. However, over the next few decades we have ample opportunity to develop alternatives such as advanced reactor concepts or new accelerator-based subcritical systems (or some combination of the two) that could make it attractive both economically and from a proliferation standpoint to burn fissile materials. Such technologies may even help to usher in a new era of sustainable, publicly acceptable nuclear power in the next century. <p>
Dealing with the nuclear materials legacy will require close collaboration with Russia on weapons-grade material, followed by collaboration internationally on civilian nuclear materials and the entire fuel cycle. In addition, it requires a commitment now by our government to develop technologies that will provide new options to solve the critical legacy of the Manhattan Project. Think of what we could do in 50 years if it took us less than three years to get to Trinity. But, remember that the scientific foundations for Trinity were laid during the first 40 years of science in this century. We must continue to lay the scientific foundations for the technologies of the next century.   <p>
The third challenge is dealing with the legacy of 50 years of nuclear weapons production and nuclear power -- that associated with nuclear waste and environmental cleanup. If we apply the principles that we learned during the Manhattan Project -- keeping a focus on our mission and applying science to that mission -- we will be able to deal with the legacy without breaking the treasury. The approach, however, will be different than that of the Manhattan Project. The cleanup job cannot be done in three years, and it must involve the public so that an acceptable level of risk can be built into the desired final solution. <p>
The Manhattan Project changed the world forever. If we learn from its lessons, we can make certain that its legacy will live and continue to change the world in a positive way over the next 50 years. <p>