Led pivotal international programs to convert weapons-grade nuclear materials for civilian use and enhanced security cultures to guard against their mishandling and misuse

The threat posed by the proliferation of nuclear and radiological weapons remains one of our nation’s most important national security challenges, with the U.S. government working globally to reduce the volume of these dangerous materials, to prevent their misuse and to improve security and safety practices.

Kara De Castro of the National Nuclear Security Administration has played a pivotal role in the U.S. effort to protect plutonium and enriched uranium from theft, diversion and sabotage in more than 30 countries, provided training to employees at nuclear facilities overseas, and authored international guidance to enhance the security culture for the handling of nuclear materials.

“Three hundred million Americans and everyone else on the planet are safer because of Kara De Castro’s nuclear security work and all of the contributions she has made,” said Lisa Gordon-Hagerty, the undersecretary for nuclear security at the Department of Energy.

De Castro’s work worldwide has resulted in the conversion of 17 metric tons of highly enriched uranium— the equivalent of 446 nuclear weapons—to a lower grade, mitigating the risk of the uranium being used for nuclear explosions and, in some cases, making the material suitable for use as commercial nuclear fuel.

For example, De Castro worked with 14 sites in Russia and seven in Ukraine to protect nuclear materials and improve security, and she spent time working on important security issues with Belarus and Belgium. She was the primary energy and nonproliferation advisor to the U.S. embassy in Pakistan, and despite the disadvantage of not being able to go to nuclear sites in China, she established a training center to teach about nuclear security.

“Kara’s leadership resulted in enhanced nuclear material security at Russian weapons production facilities and other former Soviet Union facilities in direct support of U.S national security objectives,” said Teresa Tyner, director of NNSA’s Office of Business Services.

“Kara provided expert advice on the design, installation, operation and sustainability of nuclear materials protection, control and accounting systems,” Tyner said.

Regina Galer, the National Security Council’s director for South Asia, said De Castro has been “successful all over the world,” bringing a mix of “technical and interpersonal skills” to the job and exhibiting both a toughness and diplomatic approach during negotiations with foreign officials.

“She has managed to earn people’s respect, build productive relationships and openly advocate for U.S interests in a way that helps secure nuclear material,” Galer said.

Gordon-Hagerty said De Castro did an amazing job “as an American coming in to structure nuclear programs in different countries.” She was able to “overcome hurdles and obtain the trust and confidence of her foreign counterparts,” Gordon-Hagerty added.

As program director for nuclear security engagement from 2015 to 2018, De Castro focused on implementing training and improving the security culture at nuclear facilities worldwide. In this role, she collaborated with the International Atomic Energy Agency, which has 171 member nations, and authored international guidance to enhance the security culture for the handling of nuclear materials,

Tom Wander, former director of NNSA’s Materials Consolidation and Conversion program, called De Castro’s work on the nuclear security culture “revolutionary.” He said it “involves standards for everyone who works at a site, from the janitor to the site director.”

“It has to do with attitudes and behaviors, which is difficult to get your hands around unlike sensors or an alarm gate,” Wander added. “It was hard for foreign countries to know exactly how to implement something like that, which would make all of the physical security measures more effective.”

De Castro said she is most proud of her work in Russia to convert some of their highly enriched uranium to a lower grade and make the sites safer, and her efforts to prioritize creation of security culture rather than simply getting the right protective equipment in place at nuclear sites.

“They were not really thinking about how people have to operate the equipment effectively in order to make the whole system work,” De Castro said. “But it’s critical to focus on how the human element impacts the effectiveness of nuclear security.”