Future Tense for Apr. 30, 2007
One of the scariest books I’ve read is “The Curve of Binding Energy” by John McPhee, my favorite non-fiction writer.
In the early 1970s, McPhee became acquainted with physicist Theodore B. “Ted” Taylor, who worked at Los Alamos National Laboratory from 1948 to 1956. Dr. Taylor designed some of the smallest (W54), most efficient (Hamlet) and largest (Super Oralloy Bomb, or “SOB”) nuclear fission weapons ever built. Taylor later worked as a consultant to, among other agencies, the U.S. Atomic Energy Commission, for which he studied the International Atomic Energy Agency’s capability to stop nuclear arms proliferation.
McPhee and Taylor visited nuclear facilities around the United States. Taylor had become seriously worried that the only thing preventing a terrorist or rogue nation from building and using an atomic weapon was the lack of suitable fissionable material: enriched uranium or plutonium. He showed McPhee the numerous points in the nuclear fuel cycle where material could be diverted.
In the 1960s, officials from the Atomic Energy Commission and the nuclear power industry said Taylor was wrong; that no private individual or group could build an atomic bomb. They said Taylor, a brilliant physicist, incorrectly assumed many people were as smart as he is. They reminded Congress that the Manhattan Project, the top-secret World War II project to build the first atomic bombs, cost hundreds of millions of dollars and the talents of some of the world’s most brilliant scientists and engineers.
Taylor pointed out that once the science was done, only engineering remained.
Also, he said, much of the scientific knowledge had become readily available. At a conference in the Atomic Energy Commission, McPhee wrote, Taylor once talked about how uranium’s density changes under pressure. An AEC official quickly cautioned Taylor never to repeat that information in public, because it was an essential secret of the atomic bomb. Taylor said he’d looked up the numbers the day before in the Encyclopedia Americana.
When I read “The Curve of Binding Energy” in 1974, I felt Taylor was right. By that time, 20 years after Hiroshima and Nagasaki, lots of people knew how to build an atomic bomb.
After World War II, my father, a civil engineer, took at least one course in nuclear physics. He kept his textbooks. I read them while I was still in high school. With that information, access to a decent university library and information the Atomic Energy Commission sent free on request to students interested in scientific careers, I knew most of the concepts required to build an A-bomb.
Really, all you need is less than 40 kilograms of highly enriched uranium or 25 kilograms of plutonium oxide or 10 kilograms of plutonium metal. Keep it separated into at least two “non-critical” quantities. Slam the two together when you want a big bang. Dropping one onto the other from a 20-foot ladder would work, if you’re suicidal. It’s that easy.
Since 1974, many books have published the formulas and materials data to calculate a nuclear cross-section -- once known jokingly among physicists as “the broad side of a barn door” they struck to cause fission -- and other once-secret data.
Every country that has built and tested an atomic bomb has succeeded on the first try. The list includes China, India, Pakistan and South Africa (the last has destroyed its arsenal). Israel probably has nuclear weapons, but neither confirms nor denies it, and North Korea has tested a bomb, but no one knows if they had more than that one. More than 20 other countries have the experts, most of the materials (especially high explosives) and the industrial tools to build atomic bombs.
But in the 30-plus years since “The Curve of Binding Energy” came out, no terrorist has built or detonated a nuclear bomb.
The main obstacle in any would-be bombmaker’s path is obtaining fissionable material. It’s not for sale — when the old Soviet Union broke up, Muammar Khadafi of Libya offered millions for a nuclear weapon or for fissionable material, but found no suppliers — and it costs a fortune to make.
Many nations have tried creating fissile material. Most have done it in secret, which is why I find Iran’s case interesting. The Iranians freely admit making enriched nuclear fuel, but categorically deny they will use it for weapons. In contrast, nations such as Iraq, South Africa, Israel, Argentina and North Korea all concealed their fuel-enichment programs. Iraq’s labs weren’t discovered until Saddam Hussein lost the first Gulf War; they were destroyed in 1991. South Africa’s effort didn’t become known until after it tested an atomic bomb. Argentina’s activity came to light only after a coup unseated its military government. Personally, I think Brazil is more likely than Iran to be secretly producing enriched uranium or refined plutonium for a nuclear bomb.
Anyway, near the end of “The Curve of Binding Energy,” McPhee tells how he and Taylor walked around the World Trade Center, entered an elevator, punched a button at random and got out on the 40th floor.
“I will tell you this,” Taylor said. “Just to make a crude bomb ... with a better than even chance of knocking this building down, all that is needed is about a dozen kilos of plutonium-oxide powder, high explosives and a few things anyone could buy in a hardware store.”
In a moment of premonition, that passage chilled me. I recalled it instantly in 1993, when I heard terrorists had bombed the World Trade Center.
The towers fell in 2001, of course, and Taylor died in 2004. McPhee long ago turned his attention to other subjects (his latest book, “Uncommon Carriers,” came out in June).
And work has begun on Freedom Tower, the successor to the World Trade Center. Now I can’t help wondering whether Taylor’s fears will become reality there or somewhere else ... in the future.