John Fialka, Staff Reporter
The Wall Street Journal
8/2/2000

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LOS ALAMOS, N.M. -- When John Richter retired from Los Alamos National Laboratory three years ago, he took with him nearly the equivalent of China's entire experience with nuclear weapons. China at that point had built and tested 45 warheads. Dr. Richter, one of the lab's pre-eminent Cold Warriors, could claim 42.

America's No. 1 nuclear-weapons laboratory has been plagued by security lapses, allegations of espionage, forest fire and budget cuts. But there's a far bigger problem at Los Alamos: As wizards like Dr. Richter retire, they are taking with them invaluable expertise about just what makes bombs work. And raising a new crop of experts to take their place will be difficult,

sparking questions about the reliability of the country's 6,000-plus warheads. There are only about 50 people in the U.S. who, like Dr. Richter, possess both the know-how to make a nuclear weapon and the "fudge factor"-- the memory of last-minute tweaking and intuitive shortcuts that made some of the nation's 1,000 or so nuclear-weapons tests work.

Attrition has taken a toll on a program that had its heyday in the Cold War. But inattention also has played a part. Although the U.S. failed to ratify the Comprehensive Test Ban Treaty last autumn, it stopped nuclear tests in 1992. For several years after, there was scant effort either to recruit new experts or to preserve and pass on existing lore. The result is that half of the designers at Los Alamos with design and testing experience are in their mid-50s. Within four years, they're likely to retire.

"That's the race we're running,"says John Pedicini, who is 43 years old and one of the youngest designers here. "Will there still be enough of us around to do the job?"

Contrary to folklore, the art and science of making a thermonuclear weapon aren't readily available in blueprints or on renegade Web sites. While all designs end up with the warhead's two crucial components -- the hydrogen bomb and the atomic bomb that triggers it -- the challenge has always been determining whether the device would explode or fizzle.

"In the old days, we made a lot of changes in weapons development on the fly,"says Donald R. McCoy, director of the lab's computer-simulation program, where testing now takes place. "There were a lot of things we did under deadline pressure that weren't recorded. The drawings we worked with weren't updated."

Now the lab is racing to fill the gaps in knowledge and staff. Dr. Pedicini calls making nuclear weapons and prolonging their effectiveness "a contact sport"that requires collisions between young, creative minds. "We have to transfer knowledge, experience and intuition"to that new generation, he says.

How do you transfer intuition? One of the answers has been to bring back Dr. Richter. A balding, avuncular physicist who is now 67, he headed the weapons-design group from 1978 to 1981. He is one of the star lecturers and is writing one of the basic textbooks for a new three-year course at Los Alamos called the Theoretical Institute for Thermonuclear and Nuclear Studies.

Titans, as it is known, is intended to produce the next generation of weapons designers. The one dozen candidates admitted every two years need a security clearance and a Ph.D. in physics or another weapons-related science. Then their real education in the art of bomb-making begins. "I try to cultivate older designers around here because you often get these bits of experience that sort of live in the walls, so to speak,"says student Charles Nakhleh, a 33-year-old physicist.

During the 1960s, Dr. Richter functioned as the lab's Mr. Fixit. He would get atom-bomb designs from other people and figure out how to make them work. "There are those that are going to work no matter what you do to them,"he says. "Then there are others where you're going to have to work hard to get any yield at all."

He found atom bombs, the trigger devices, to be finicky things. One design contained hidden errors that made it work the first and second time, but not the third and fourth. Making changes to the design brought the risk of a fizzle, which could be either a failure to detonate or a detonation below the desired "yield,"or power. Dr. Richter and other bomb designers also refer to fizzles as "falling off the edge of the cliff."

The Richter approach was to try something and test it, and if it didn't work, try something else and test that. "I fell off the cliff a number of times,"he says proudly, adding that sometimes he learned more from his fizzles. Now he lectures students whose only experience near the "edge of the cliff"will come from tinkering with simulated weapons on supercomputers. One of the assignments for Dr. Nakhleh and the other Titans students will be to figure out the science that explains exactly what changes Dr. Richter made and then spell them out in scientific equations for future reference. Dr. Richter is skeptical: "The idea that you can have a computer code that has all the secrets in it is bull."

Dr. Richter was drawn to Los Alamos in 1958 through a combination of patriotism, skiing and camaraderie. Fresh from the University of Texas, he saw the lab as a way to serve his country and ease the guilt he felt about having a student deferment during the Korean War. He had also discovered that the nearby mountains are a "truly fabulous ski area."Then there were the 3,000 Ph.D.'s at the lab. "If you read about some phenomena in some field that you wanted to know something about, the top dog in it probably lives a mile or so from Los Alamos."

Nuclear-weapons design was then taught in a kind of medieval apprenticeship. Dr. Richter hung around one or two bomb designers to see how they did it. "You worked for these guys until you didn't need them anymore,"he says. "The quicker you did that, the quicker you could do more things on your own."

His first trip to the Nevada Test Site came in 1962, shortly after Russia had shaken the world with a 58-megaton hydrogen bomb, the largest test ever held. Although catch-up was the order of the day, the timing of Dr. Richter's test was coincidental -- his weapon was a response to a different Soviet threat. Code-named Aardvark, it was a prototype for a low-yield artillery shell designed to stop Russian tank columns from coming into Western Europe. The designer was 29.

Was he nervous? "You always are,"says Dr. Richter, with a slight grin. "You spend months and months preparing for something and, finally, it tells you if it's OK, or whether you're a damned fool."Aardvark, he recalls, "was a real ground-shaker."