March 7, 2004
Nuclear arms control may reduce terrorism as well as avoid Hiroshimas, Garwin says
By Dawn Levy
Nuclear arms control no longer aims only to lower the chances of attacks with weapons launched on missiles or dropped from airplanes. Today, it also aspires to reduce the risk that terrorists will attack with improvised nuclear weapons, internationally renowned physicist Richard L. Garwin told a Cubberley Auditorium audience March 9 during the 2004 Drell Lecture.
"The problem is to avoid Hiroshimas, to avoid big cities being subjected to nuclear attack, in an era when it is totally incomprehensible that the Russians will use their 18,000 nuclear weapons against us," said Garwin, a winner of the 2002 National Medal of Science and the 1996 Enrico Fermi Award. His speech, titled "U.S. Nuclear Weapons and Nuclear Explosion Testing," was sponsored by the Center for International Security and Cooperation (CISAC). It came a month after President Bush sent a budget to Congress that would reduce spending on important nonproliferation programs while increasing money for the nation's nuclear stockpile.
Garwin, the Philip D. Reed Senior Fellow for Science and Technology at the Council on Foreign Relations, chaired the Arms Control and Nonproliferation Advisory Board of the State Department from 1993 to August 2001. In 1998, he was a member of the nine-person Commission to Assess the Ballistic Missile Threat to the United States, chaired by Donald Rumsfeld.
"There will be terrorist nuclear explosions in cities in the next years," Garwin asserted, presenting a scenario with the potential to kill hundreds of thousands of people. "It shouldn't be imagined that a nuclear weapon made by terrorists, maybe with some advice from others and using highly enriched uranium metal, would have a low yield. It could perfectly well have a full yield of 10,000 tons of high explosive."
Reducing the odds of such an attack will require better control of highly enriched uranium-235 and plutonium, the fissile materials from which nuclear weapons are made, Garwin said. It will require expanded intelligence capacity, from better infiltration of terrorist groups to improved detection of smuggled weapons-grade uranium and plutonium. And it will require a rapid and serious reduction of nuclear inventories, especially in the United States and Russia, to reduce the risk of security breaches.
"We need to spend a lot more money [on nonproliferation]," Garwin said. "Compare the billion dollars a year spent on the Nunn-Lugar Cooperative Threat Reduction [Program] with the $87 billion appropriation a few months ago for a year of war in Iraq -- a war which was held by the possibility of weapons of mass destruction. But these are real weapons of mass destruction that we aretalking about here."
Shrinking the stockpile to reduce risks
In nature, only seven-tenths of one percent of uranium occurs in the 235 form; the rest occurs as uranium-238. Enriching material with uranium-235 allows its use in nuclear power reactors, which provide about 17 percent of the world's electricity, and in weapons. In comparison, plutonium for weapons is made from uranium in nuclear reactors.
Garwin, who with Nobel Prize winner Georges Charpak wrote the 2001 book Megawatts and Megatons: A Turning Point in the Nuclear Age?, said he generally favors nuclear power. But he warned of a dangerous connection between it and nuclear weapons proliferation. States desiring nuclear weapons often choose a line of nuclear power reactors that allow them to get their hands on enriched uranium or separated plutonium, he said. In fact, President Bush has proposed that many countries not have the full fuel cycle. Operators would use reactors to produce power but forgo reprocessing, which could produce potential bomb material.
Because the United States and Russia maintain the largest stockpiles, arms reductions among them could have the largest ripple effect in reducing risks.
"The Soviet Union no longer exists, and the half of it that constitutes Russia and has all the nuclear weapons is not our enemy," Garwin said. "In fact, they are our friends. We have some difficulties with those particular friends, but we have difficulties with some friends. However, nobody believes that Russia is going intentionally to launch nuclear weapons against the United States or we will launch ours against them."
Nevertheless, he said, we maintain thousands of nuclear weapons ready to launch at a moment's notice simply because the other side has the capability to do the same. "The fact that we have no interest in such a strike doesn't cut any ice in this calculus," he said.
Garwin recommended reduction from more than 10,000 weapons each to 2,000. Such reductions look like sacrifices but really are in our national interests, he said. Eventually the number may limbo to 1,000 each -- "enough for any conceivable purpose." Garwin said he couldn't see getting rid of all nuclear weapons.
Russia has enough uranium-235 and plutonium to build tens of thousands of additional weapons. The United States has a program to buy 500 tons of weapons-grade uranium from Russia over 20 years for $12 billion. The uranium from disassembled weapons may eventually find use in nuclear reactors.
For now, much of the Russian material is spread over dozens of sites, many of which are improperly safeguarded. While U.S. nuclear wastes are eventually secured in the Yucca Mountain repository in Nevada, Russian wastes are not centralized. Garwin said consolidating fissile material at fewer sites may help "prevent robbery, not by a few people who are amateurs but teams who are equipped with powerful weapons and some of whom are willing to die, as is the case with terrorists."
To test or not to test
Nuclear weapons have been tested since 1945, first in the atmosphere and later underground, underwater and in space. Testing verifies that weapons will work either after they are produced or after they are stockpiled, and determines their effectiveness against targets. But are tests necessary? Can a safe and reliable nuclear stockpile be maintained if testing were banned?
"To protect the environment and minimize the developmentof new nuclear weapons, there's long been interest in a total ban on nuclear testing," said Garwin, who worked on this in 1958 with Professor Emeritus W.K.H. "Pief" Panofsky, founding director of the Stanford Linear Accelerator Center. A treaty banned all but underground tests in 1963.
After deliberating, America's top nuclear experts concluded that the nation's nuclear deterrent could be maintained safely and reliably without underground tests, provided sufficient resources were provided. America spends $6 billion per year on stockpile stewardship, Garwin said. Whether this is enough is debatable, he said. A comprehensive test ban treaty was signed in 1996 but has yet to be ratified.
The U.S. stockpile contains atomic bombs, such as the onesdropped on Hiroshima and Nagasaki, and hydrogen bombs, which are 20 times more powerful. Smaller weapons may in fact be more useful, Garwin said. "A very big weapon just destroyed more than there was to destroy," he said. "It was better to divide up the payload for the bomber or the missile into smaller and more accurate nuclear weapons."
Lately, there has been pressure to add weapons to the stockpile -- "bunker buster" bombs for destroying facilities built deep underground and "agent defeat" weapons for destroying chemical and biological agents housed in shallowunderground facilities. While the Department of Energy has no commitment to build new nuclear weapons, Garwin said, "they are enthusiastic about analyzing them, in part to maintain the skills of the nuclear weapon laboratories and in part because of congressional pressure." Analysis may mean testing.
Bunker busters, which can destroy hardened facilities down to hundreds of meters, have been in our inventory a long time, Garwin said. "It's the B53 nine-megaton nuclear bomb. But nine megatons exploded on the surface creates lethal fallout over thousands of square kilometers, and especially if the other side has put the hardened facility under a city. It would destroy the entire city. Who knows what that facility was doing or worth in the first place. There is a call for less powerful weapons to do the same job."
He had similar reservations about agent defeat weapons. If exploded close to an underground facility for weaponizing, say, anthrax, the radiation from an agent defeat weapon could sterilize the anthrax, and the heat could destroy it.
"Unfortunately, a shock that is that strong is also plenty strong enough to make a crater and throw out the material,much of it undisturbed, into the atmosphere," Garwin said. "I've seen no calculation which shows any promise of doing what is advertised, namely destroying the [biological warfare] or [chemical warfare] material without scattering undestroyed material into the atmosphere."
Instead, Garwin said underground control centers and factories may be more safely destroyed with non-nuclear attacks at the entrances and exits.
The Drell Lecture is named for physicist Sidney Drell, a former deputy director of the Stanford Linear Accelerator Center and a founding co-director of CISAC. The lecture addresses a national or international security issue that has important scientific or technical dimensions. Stanford alumni Albert (BS '49, Engr '49) and Cicely (AB '52) Wheelon established the lecture and attended this year's talk. Albert Wheelon was the CIA's first deputy director for science and technology and a CEO of Hughes Aircraft.