In 1942 scientists in Los Alamos, New Mexico, began work on a top-secret project code-named “Project Y.” Today the world knows Los Alamos National Laboratory (LANL) for its role in the Manhattan Project and the nuclear weapons that evolved from that historic work.
Fifty years later, at the Nevada Test Site, the United States staged its last underground test of a nuclear weapon. Since 1992, the nation has observed the terms of the Comprehensive Test Ban Treaty. In the post–Cold War era, with a moratorium on the live testing of nuclear weapons, the scientists at LANL and its partner laboratories have relied on other means to certify that the existing stockpile remains stable, safe—and ready for action, should the need arise. The new strategy, known as Science Based Stockpile Stewardship (SBSS), is based on what Los Alamos Science calls “an iterative cycle of theory, experiment, evaluation, and innovations.”
Frank Addessio, who has spent the last half-century modeling scientific problems, takes the long view. Reflecting on his 40 years at Los Alamos, he says, “Our job here is still as important as it was. It’s just that there’s been a shift away from doing experiments on the large-scale components. We can’t test full-scale devices, so we’ve had to come up with other ways of certifying them.” At 73, he’s lived through some historic changes. Even as technology evolves, and history and politics shape the research agenda, it’s the underlying theoretical questions about materials behavior that excite him.