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Thom Mason takes the helm at Los Alamos

The Laboratory’s 12th director discusses national security, the annual assessment letter, and why he chose physics over English in college.
March 1, 2019
Photo of Thom Mason

Laboratory Director Thom Mason.CREDIT: Michael Pierce


"We have to make sure our scientific and engineering capabilities stay ahead of the challenges in the stockpile."- Thom Mason

Perhaps it’s no surprise that Thom Mason, who was director at Oak Ridge National Laboratory for 10 years, is now the director at Los Alamos. “I grew up in a science family,” he explains. “My dad worked at a Canadian national lab, so it was sort of the family business, and it never really occurred to me to do anything else.”

He pauses, reconsidering. “I did think about doing an English degree,” he says. “And I decided that if I did physics, I could still read books. But if I took English, I probably couldn’t have physics as a hobby.”
Fast-forward nearly four decades, and reading is still one of Mason’s hobbies, alongside hacking consumer electronics, cycling, skiing, and exploring his new hometown of
Santa Fe, New Mexico.

But time for such activities is in short supply these days, as nearly all of Mason’s energy is focused on his new job at Los Alamos. “There is something healthy about really looking at things and trying to understand what’s working and what’s not working,” he says of his new role with Triad National Security, which began managing the Lab on November 1, 2018. “This is an opportunity to take a fresh look at things, make some changes that need to be made, and emerge as a stronger organization as a result.”

Here, Mason explains just how he intends to do that.

How is Los Alamos different from Oak Ridge?

Both labs were founded in 1943, so they have common roots in the Manhattan Project—the crash effort to bring the best of science and technology to bear on the crisis of the day. The difference—and one of the reasons I find Los Alamos interesting—is that Oak Ridge is first and foremost a science and energy lab, although it does a lot of important national security work. Los Alamos is clearly, front and center, a national security lab, although it has a lot of outstanding science and energy technology work. That focus on national security and the nuclear deterrent brings challenges. This is a high-consequence place. It’s high consequence in terms of the impact of the work that’s done, and it’s also high consequence in terms of what could possibly go wrong. It’s important that the work be done well, and that’s certainly a challenge I relish and everyone on the leadership team looks forward to.
Thom Mason sitting at a desk and writing in a notebook.

Thom Mason.

What is your vision for the weapons program?

As we look forward, we have to deal with the reality of change in the stockpile. Weapons have been in service longer than their original design intent. In response to that, the Lab has responsibility for things like life extension programs, modifications, and alterations.

In that world where we are starting to see more change, how do we certify weapons? What are the tools we need to be able do that? We have progressively higher performing computers with codes that are optimized to run on them, so we can simulate things with a fidelity that we couldn’t do previously—or at least we will be able to in coming years as we get to exascale computing and beyond. We have new experimental techniques that are giving us better-quality data to validate those simulations.

So the question will be: Does the rate of improvement of our scientific and engineering understanding of the stockpile stay ahead of the rate of change that’s occurring in the stockpile? That’s the thing I’m most focused on in terms of the longer-term direction of the Lab. We have to make sure our scientific and engineering capabilities stay ahead of the challenges in the stockpile.

In September, you will sign the annual assessment letter that concludes the health of our nuclear deterrent. How will you make sure you’re confident signing that letter?

That letter has four components: the state of existing stockpile, whether there is a need to resume testing, the adequacy of the tools, and the readiness to resume full-scale nuclear testing.

There’s a large enterprise that’s focused on the state of the stockpile. My responsibility is to make sure that the enterprise is properly staffed and funded and asking the right sorts of questions. There are also independent Red Team processes to crosscheck the enterprise and then of course the very important function between Livermore and Los Alamos to peer review one another. All of that can help increase my confidence that we have a good and correct technical judgment, whether it’s on the state of the stockpile or the ability to continue the current posture of not doing full-scale nuclear testing.

In terms of the adequacy of the tools, I look at the types of questions we have about the stockpile. Do we—and will we—have the ability to answer questions that we see arising in the future? You can’t wait until a question arises to start working on it.

In terms of the readiness to resume testing, a lot of the things that go on now at NNSS are exercising that system to some extent—there’s more going on now than there has been in many years, so that helps give me confidence.

I’m not a weaponeer by training, but I’m quite confident with the technical content. I am learning the specifics of Los Alamos’ stockpile responsibilities. We’ve got a great team. Even though the letter gets signed by the Lab director, it’s really the culmination of a very large effort that draws on people across the Laboratory.

A submarine on the surface of the water and a missile rising into the sky.

How do you see the Lab’s relationship with the military?

In the end, it’s the military that deploys the systems that we create and develop. They set the requirements that the NNSA has to deliver, using the labs and the plants. Los Alamos has a long history and tradition of working with the military to understand those requirements.

It’s also noteworthy that we have a lot of former military on staff at the Lab—approximately 10 percent of our workforce. People who have served in the military see working at the Lab as a way to apply their military experiences and continue their national service.

What do you think is the biggest national security challenge of the future?

One of the challenges of the future is there’s not a single well-defined national security challenge. China is being aggressive—and successful—in developing its scientific and technical capabilities. Technologically and economically, China probably is a more powerful player than Russia, although from a nuclear point of view, Russia obviously has a larger stockpile. Add to that the various wannabe nuclear powers and non-state actors, and there is no longer a single biggest challenge that we can identify and organize around.

In the end, it’s about understanding the world around us. What technological surprises are lurking in the future that will require some new kind of response that—being at the forefront of cutting-edge science and technology—we might be able to anticipate and position for?

If we have people who understand the physics and the chemistry and the biology and environmental science, that understanding allows us to take action. That’s part of the reason we have a place like Los Alamos.