In nuclear reactors, the formation and movement of bubbles in boiling water turns out to be a critical issue: “If instead of nice little bubbles leaving the surface of the fuel, you get a film of vapor forming, the temperature of the fuel rods can increase,” Gilman says. “When this happens, you have reached critical heat flux. The concern is that if the temperature of the fuel rods gets high enough, the structural integrity of the rods might be compromised, and even fail.”
Gilman’s studies focus on optimizing flow conditions to achieve maximum power without compromising safety. She has just begun the first phase of her project, which entails building a software model that describes precisely what is taking place inside reactors as water heats up and approaches the boiling point. “We want to predict critical heat flux better, so we can stay away from it,” Gilman says. “My research looks at the physical phenomena, such as the surface condition of the rods, and the velocity and temperature of the water flowing across the surface, that might drive heat transfer.”
Gilman arrived at this computation-centered project, and even her research topic, in a roundabout way. As a chemistry major at Valparaiso University in Indiana, she attended a lecture on nuclear isotopes and was instantly mesmerized. “At first I was kind of afraid to tell anybody about my interest in nuclear science, because nobody I knew ever discussed the field, and I was worried they’d think I was strange,” Gilman recalls. After junior year, she found her way to a Department of Energy summer school in nuclear and radiochemistry, which exposed her to different subjects in nuclear science. Says Gilman, “The thing that really got my interest was the possibility of transmuting nuclear waste,” to reduce radioactive stockpiles.
She returned to Valparaiso and immediately signed up for courses in nuclear physics and quantum mechanics, determined to pursue nuclear science as a graduate student. After some hesitation, she applied to MIT. “I was afraid I wouldn’t fit in, given my chemistry background,” she says. After a campus visit, though, she says, “I realized I loved the department” — particularly after she discovered she shared a passion for running with Professor Emeritus Sidney Yip.
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