We explore the most powerful nuclear test reactor in the world, just miles from Idaho Falls
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EDITOR’S NOTE: Throughout 2024, EastIdahoNews.com is working with the Idaho National Laboratory to celebrate its 75th anniversary. Throughout the year, we’ll publish stories highlighting the history, achievements and trials of the U.S. Department of Energy’s desert site. We’ll explore INL’s influence on eastern Idaho, and its day-to-day impact on local people.
IDAHO FALLS — Many elements of Idaho National Laboratory are rooted in rich history and ingenious technology, driven by a bold vision to redefine the future of energy, national security and medicine.
One of the most prominent examples is nestled just 47 miles west of Idaho Falls, a monumental testament to human ingenuity and technological excellence.
“The Advanced Test Reactor is one of INL’s flagship facilities. It’s the world’s most powerful test reactor,” says Joseph Campbell, the communications liaison for the Advanced Test Reactor. “No country has come close to the power level, the versatility, and the number of test bases we can handle all at once.”
In 1949, the U.S. Atomic Energy Commission created the National Reactor Testing Station, which would later become known as Idaho National Laboratory.
In the early 1950s, a brown-haired, spectacled scientist named Deslonde de Boisblanc traveled from Oklahoma to Idaho to work as a neutron physicist and contractor for the testing station.
Little did he know, he would later become the godfather of ATR, or as some even call him, an “Oppenheimer” of INL.
“He was one of the very first neutron physicists to work here at what we now call the Advanced Test Reactor complex,” says Campbell. “I look at it as he was one of the Oppenheimers of the INL site. We have been lucky enough to have quite a few, I think, that we are looked at as very, very pioneering in the particular field that they focused in.”
Innovation by the dashboard lights
In the 1960s, the Atomic Energy Commission was seeking a new way to design test reactors to become more efficient, powerful, and marketable to their customers.
“The Atomic Energy Commission at the time told the contractors operating at the INL site back then, they basically made it a competition,” says Campbell. “Deslonde de Boisblanc (was contracted) for Phillips Petroleum, and one of the other competing companies had one of their leading neutron guys start coming up with the design concepts.”
They evaluated both design concepts – and de Boisblanc prevailed with an idea that would became known as the Cloverleaf Core concept.
The idea was to design the reactor’s core in the shape of a cloverleaf. This would create nine excellent spots for conducting tests.
There are many rumors floating around as to how de Boisblanc came up with the model for what would become the most powerful test reactor in the world, but Campbell says one story seems to reign supreme.
“The story is that de Boisblanc, on his way home from work one evening, just kind of had a brainstorm,” says Campbell. “He drew it out in the dust on his dashboard on his way home from the site one day.”
His design created a previously unheard-of capability for materials testing, allowing data to be produced at speeds up to 10 times faster than a traditional nuclear reactor.
ATR acts as a time machine, providing decades of data on nuclear fuel and material in a fraction of the time it would take for any other reactor.
For example, a commercial reactor can provide 10 years of data, but it will take 10 years to get it. ATR can provide 10 years of data in less than a single year because of the way its designed.
“The more (de Boisblanc) looked at this cloverleaf shape, he realized that it would create nine very valuable test positions,” says Campbell. “He gave it other unique aspects that made it absolutely ideal for this kind of research. It is kind of a testament to his genius that ATR still has not been topped as far as test reactors go.”
Kevan Weaver, the chief technical officer at the Advanced Test Reactor, says this kind of technology is still at the top of its game, leaving other countries struggling to come up with an idea to out-power ATR.
“It is the most powerful test reactor in the world by about two times. The next most powerful ones, there’s one in China and there’s one in Russia, and they’re about half the size of this one,” says Weaver. “And so this one is by far the most powerful test reactor.”
Illuminating everyday life: The impact of ATR
ATR is a pressurized water test reactor used to study the effects of intense radiation on reactor materials and fuels.
But what does that mean for everyday folks like you and me? What’s in it for us?
For the past 75 years, ATR has been advancing knowledge and research in many fields, including medicine, national security, aviation and deep space exploration.
For example, ATR is the only place in the world creating the specific isotope needed for a particular type of cancer treatment: medical-grade cobalt-60, one of the necessary ingredients for gamma-knife therapy to treat brain tumors.
“Beyond the nuclear fuels and materials that we do, any time you can produce neutrons, you can make elements that then become useful for medicine,” says Weaver. “They make the cobalt, they put it in a little package, and it’s like a little X-ray machine.”
ATR can also produce many other isotopes – even one that helps NASA explore deep space.
A special type of plutonium isotope created at ATR is used to keep the power going in astronauts’ and space satellites’ solar panels. This helps them stay powered and continue exploring and studying space, even as they move away from the sun.
“It’s a very specific kind (of isotope) that emits radiation that only goes a small distance but gives off a lot of heat,” says Weaver. “So it makes a little battery. And actually, here at the INL, we fabricate those batteries for NASA.”
ATR also heavily contributes to U.S. Navy projects, helping with new ideas to expand the longevity and success of various missions.
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“About half of the work we do is for the naval nuclear propulsion programs, for the U.S. Navy,” says Weaver. “If you look at all of the submarines and the aircraft carriers that use nuclear power plants to run those ships or boats, all that work was done here. And they’re always advancing.”
According to Weaver, the current Virginia class submarines no longer have to stop for fuel because of the work at ATR.
What used to be a long, expensive trip to the coast to refuel the reactor cores has evolved into boats having enough fuel to last the lifetime of the boat itself, between 30 and 35 years.
“All the work that the Navy has done with us here has progressed us to the point where now we have 30- to 35-year cores,” says Weaver. “The next class of submarines, 40- to 45-year cores. And so they’re just continually advancing.”
ATR glows in the dark: the Cherenkov effect
If you ever get the chance to visit ATR, you will be one of a very small number of people who can say they’ve witnessed electrons moving faster than the speed of light … at least, the speed of light in water.
ATR provides an up-close look at one of the rarest phenomenons in known history, the Cherenkov effect.
Cherenkov radiation is visible radiation on the light spectrum.
Inside a reactor, a lot of energy is released in a very small area, and water molecules energize so quickly that they travel faster than the speed of light in water.
“The ultimate speed of light is in a vacuum. That is a speed limit — you can’t go faster than that,” says Weaver. “But if you get into another medium like water, that speed goes down, which means you’re not going past the ultimate limit, but you (referring to the electrons) are going faster than the speed of light in that medium.”
Eventually, the electrons have to slow down, and when they do, they give off light, and luckily, it is visible to the human eye in a bright blue hue.
“We actually get to see it. It’s super fortunate,” says Weaver. “It could have been in some other part of the spectrum we could never see.”
The test reactor for the test reactor: ATR Critical
In a room adjacent to the world’s most powerful test reactor, a young woman leads a team of reactor technicians, many of whom are significantly older than she is.
Twenty-nine-year-old Alyssa Spence, reactor supervisor for ATR Critical, says it’s her job to supervise repairs, maintenance, and the overall well-being of the test reactor, for the test reactor.
“ATR Critical, as I like to describe it, is the test reactor for the test reactor,” says Spence. “We do the low-power testing for ATR before ATR does the higher-power testing.”
Spence received her bachelor’s degree in environmental earth science from U.C. Berkeley and planned to use it to work in geology – but that didn’t happen.
“Personally, I really like geology, rocks, that kind of thing. But my dad has a Navy background. He was a Navy nuke,” says Spence. “He loved being a Navy nuke so much he recommended the job to me when I graduated from college. He sent me a listing, said I’d love it, and here I am almost seven years later.”
Spence has spent nearly an entire year in extensive reactor training when all put together, and seven years into her time at ATRC, she is at a point where she is running the show.
“The training program is extensive, and especially for someone who doesn’t have the same background as, say, someone coming out of the Navy,” says Spence. “It’s taken me a while to get to the point where I’m at currently, but it’s a very fun, interesting job.”
It’s important to know that the word “critical” isn’t as scary as it sounds. According to Spence, the “C” in ATRC means the reactor is doing what it should.
“I know it sounds scary to a lot of people if they’re not familiar with the term, but critical is actually a safe place to be in reactor operation,” says Spence. “If your reactor is subcritical, your reactor is shut down. If your reactor is super critical, you have a huge power spike. So critical is your nice steady power level. That’s where you want your reactor to be.”
Spence says the ATRC team is significantly more hands-on than ATR, given that she and her team are directly involved in the nitty-gritty of repairs and maintenance.
“We’re very hands-on as operators, so a lot of that is maintenance testing of our equipment,” says Spence. “I’m also responsible for overseeing our reactor startups, our reactor operation periods and our reactor shutdowns.”
One of the most interesting parts of ATRC is that most of its parts are original from the 1960s. This is made possible because ATRC uses low power during its experiments, meaning the equipment experiences less wear and tear.
“As a result of ATR’s higher operating powers, you do result in radioactive gases building up in the core materials themselves, control rod materials, which eventually leads to swelling, cracking and core damage if you don’t change out your components periodically,” says Spence. “Back here, our operating powers are so low that we don’t have the same issues and we’ve been able to operate for 60 years with the same control elements, the exact same core.”
If you’d like to learn more about ATR and it’s impact on the community, INL is hosting an open house on June 14. Spots will fill up fast, so register here.
All of this to say that ATR is more than just a facility – it has become a beacon of scientific advancement that has helped to place INL at the forefront of nuclear research.
To sum it up in Weaver’s words: “It is very Star Trek-ish. I love it.”
Brought to you by Idaho National Laboratory. Battelle Energy Alliance manages INL for the U.S. Department of Energy’s Office of Nuclear Energy. INL is the nation’s center for nuclear energy research and development, celebrating 75 years of scientific innovations in 2024.