Effects in action

Los Alamos staff provide weapons effects analysis for military planners.

By Jill Gibson | April 2, 2024

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Angel Padilla, standing on a pedestrian bridge in Los Alamos, says the computer simulations she produces bridge important strategy gaps for military planners. Los Alamos National Laboratory

Twenty-five-year-old Angel Padilla has devoted an entire year to blowing up bridges—simulated bridges, that is.

“Actually, what I do is run computer codes that simulate the effect of nuclear detonations on particular physical structures, such as bridges and buildings,” says the research technologist at Los Alamos National Laboratory.  “We have spent the past year focusing on one bridge.”

Padilla’s work is part of a collaboration between Los Alamos, Lawrence Livermore, and Sandia national laboratories to assess weapons effects on specified structures for the U.S. Department of Defense (DOD).

“We conduct highly complex nonlinear system modeling, with each lab using its own in-house developed computer codes,” Padilla explains. The resulting simulations have allowed researchers to examine everything from blast orientation, height of burst, and range from target. The computer models even allow scientists to consider factors such as materials used to build structures and estimated time for repairs.

“Just at Los Alamos, we have used about four million CPU hours on this one project,” she says, noting the simulations would not be possible without the Lab’s supercomputers. Running a single analysis can take three to four days. “We also do a lot of validation and verification against other lower-fidelity codes and experimental data and compare results among the three labs to create a higher level of confidence.”

Padilla, who has a background in civil engineering, started at Los Alamos in 2021 following an internship at the Lab during her master’s program. She says she never anticipated a career analyzing weapons effects but finds the work fascinating. “Keeping up with multiple projects and building and running the simulations keeps me and my team very busy,” she says. “I was surprised to learn how far-reaching and how many applications there are for the computer codes we use.”

Padilla says the information the codes generate often takes months to dissect and analyze. “While there will always be a certain level of uncertainty, the results that the three labs working together have achieved provide confidence,” says Padilla, adding that the team’s next step is to present its findings to DOD and then start analyzing the next objective. ★