Numbers and Nukes
Mathem
Buried in the southern Nevada desert, miles from anywhere, is an underground laboratory called the U1a complex where scientists carry out experiments to ensure the safety of America’s nuclear stockpile. To reach the lab, they have to journey down a literal mineshaft, a remnant from the days of the nation’s nuclear testing. It descends nearly 1,000 feet below ground surface. That means that Sean Breckling has a very long commute. Breckling is a UWM alum who majored in mathematics and graduated in 2010 into a slumped economy. Faced with seemingly slim career prospects, he enrolled in graduate courses at the University of Nevada-Las Vegas, earning his PhD in applied mathematics in 2017. Upon graduating, Breckling left Nevada to build his CV via the well-worn path of post-doctoral academic research appointments. That same path led him back to Nevada. Breckling is a senior scientist at the Nevada National Security Site, a federal research facility where scientists are tasked with helping to ensure the safety of the nation’s nuclear weapons, providing data to the Stockpile Stewardship program. “The Nevada National Security Site has a broad mission. We manage a lot of scientific research facilities,” Breckling said. This work includes “subcritical experiments,” where scientists work with chemical explosives to generate high pressure that they apply to special nuclear materials. These experiments are conducted such that a self-sustaining nuclear chain reaction, or “criticality,” is never achieved.
4 • IN FOCUS • October, 2019
One of Breckling’s roles is to support the Cygnus X-ray Diagnostic Machines. He describes this system “similar to the microscopes you might have used in any science class.” However, “instead of back-lighting samples with visible light, this machine uses gamma radiation. “I do a lot of image and data processing to that end,” Breckling added. “Many of the techniques we employ would be familiar to professional photographers, but since we’re using a radiological light source, we call it radiography.” By analyzing the images captured on Cygnus X-ray Diagnostic Machine, Breckling develops quantitative tools that he and other scientists use to better understand the results of their subcritical experiments. The work is everything he could have wanted in a job. “I’ve always gravitated to the applied sciences,” he said with a laugh. “I could have wandered into any reasonably-technical vocation. I’m more focused on how I work than what I work on.”
