HFIR: Leading the World in Isotopes and Science

For nearly six decades, the High Flux Isotope Reactor, or HFIR, at Oak Ridge National Laboratory has been one of the world’s most powerful research reactors. It has played a critical role in making isotopes for a range of applications, including space exploration, periodic table discoveries and life-saving cancer treatments. However, isotope production isn't HFIR's only claim to fame. The versatile reactor boasts world-class capabilities for neutron scattering, materials testing and analyzing samples at the atomic scale. In this episode, you'll hear from the scientists and engineers who help carry out these missions and ensure the reactor will run for decades to come.

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KEN ANDERSEN: It's amazing that 60 years later almost, it is performing at a world-leading level still.

SANDRA DAVERN: I really think this work is so important because of the hope we can give to people who have run out of options.

COLLIN BROHOLM: It's been a long and storied career of scientific contributions from HFIR, but the story is by no means ending.

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JENNY: Hello everyone and welcome to “The Sound of Science,” the podcast highlighting the voices behind the breakthroughs at Oak Ridge National Laboratory. 

MORGAN/JENNY: We’re your hosts, Morgan McCorkle and Jenny Woodbery. 

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JENNY: In February 2021, Mars gained a new inhabitant. NASA’s Perseverance rover landed on the Red Planet after a seven-month trip through space.

MORGAN: Like other missions before it, Perseverance is surveying the barren planet for traces of ancient life.

JENNY: A thorough assessment of Its landing site – Mars' Jezero crater – will take several years to complete and requires Perseverance to have a power source that will also persevere.

MORGAN: And with 150 million miles separating Mars from the Sun, solar power isn’t an option. But there is another energy source that can stand the test of time – plutonium-238.

JENNY: Plutonium-238, or Pu-238, is an isotope that NASA uses to fuel deep space missions like Perseverance.

MORGAN: However, not so long ago, there was a concern that this special isotope might be in short supply as the U.S. Department of Energy’s production of it had stopped in the late 1980s.

JENNY: And as the quantity and quality of the U.S. stockpile began to diminish, it became clear that something needed to be done if NASA was going to pursue future deep space missions.

MORGAN: Increasing the supply of Pu-238 is easier said than done. There are actually only a few places in the world where special isotopes like it and others can be made. One of those locations is at Oak Ridge National Laboratory.

JENNY: For decades the High Flux Isotope Reactor, or HFIR, has been one of the world’s most powerful research reactors, capable of making isotopes for a range of applications – including Pu-238.

MORGAN: While it took several years to ramp up production of the isotopes, thanks to HFIR, Perseverance is just the first of many NASA missions to have ORNL-produced plutonium-238.

JENNY: But Pu-238 is just one of the incredible isotopes – and scientific discoveries -- to come from HFIR. For nearly six decades, the reactor has produced isotopes used for national security, periodic table discoveries and life-saving cancer treatments, to name a few.

MORGAN: And its mission has expanded to encompass so much more than isotope production. The reactor recently marked its 500^th fuel cycle, so what better time to take a dive into the history of this unique facility and explore what’s in store for the future.

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JENNY: The High Flux Isotope Reactor opened its doors in 1965, thanks in large part to lobbying from renowned chemist Glenn Seaborg.

MORGAN: Throughout the 1940s and 50s, Seaborg and his colleagues at the University of California at Berkeley had discovered a number of elements on the periodic table -- earning him a Nobel Prize -- and were looking at ways to study and produce even heavier elements and isotopes.

JENNY: And just as a refresher, isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons.

JENNY: Seaborg, who was chairman of the Atomic Energy Commission at the time, presented a vision for a reactor with a very high neutron flux – or intense flow of neutrons.  This capability would enable the production of transuranic isotopes -- heavy elements such as plutonium and curium.

MORGAN: When HFIR opened, it had the highest thermal neutron flux of any reactor in the world and to this day, it is still one of the world’s most powerful research reactors.

JENNY: We talked to Ken Andersen, the associate laboratory director for the Neutron Sciences Directorate at ORNL, to discuss the reactor’s remarkable longevity.

KEN ANDERSEN: I think it was a really visionary piece of engineering when it was put in place in the ’60s, you can see that by looking at the design of the fuel element and to what extent that has been copied at other facilities around the world. The place where I did my Ph.D. thesis at the ILL in Grenoble in France has a fuel element, which was basically copied from the HFIR design. That's the sincerest form of flattery. There's many elements of the HFIR design that were visionary when they were done and have really withstood the test of time. I think it's amazing that 60 years later almost, it is performing at a world leading level still. It's a testament both to the design of the people back then and it's also a testament to the people who have been working and operating the reactor since then. That we've taken really good care of it.

MORGAN: While initially intended for isotope production, the elegant design of HFIR is also perfectly suited for world-leading materials science research.

ANDERSEN: There are certain isotopes that really can only be made at HFIR and only at the quality and the type of isotope that HFIR is able to produce and the quantity and it's you know, it's what the “I” in HFIR stands for, so it's not surprising that HFIR would have that strength in isotope production. The other thing which may be more surprising given the name is a neutron scattering mission. It was designed from the outset to extract intense beams of neutrons, which are used for material science. And HFIR has the highest brightness neutron beams anywhere in the world. Event when you compare it to more modern facilities, and HFIR is not the newest facility by a long stretch, but its neutron beams are still the brightest. And that means that the instruments which you build there, where you do the material science experiments can be world leading -- many of the instruments at HFIR are the best in their class. And they really capitalize on that extremely high neutron brightness produced by the reactor, so it means that we're able to deliver world leading neutron science, in materials research, you know, the next big developments in energy materials, in quantum materials, in soft matter. HFIR is working in all of those areas and delivering world-leading results.

JENNY: And what may be equally as impressive to the reactor’s longevity is its versatility. Scientists are harnessing the power of the reactor for everything from answering questions about dark matter to testing next-generation materials.

ANDERSEN: HFIR has a very varied portfolio of activities. In addition to the neutron scattering and the isotope production, it also has a very active program in fundamental physics. It also has experiments in materials irradiation. One of the key problems that we're trying to solve in delivering clean energies for the future is fusion reactors. And they promise virtually unlimited supplies of clean carbon dioxide-free energy, but it's technically really tricky. There are some really difficult materials challenges for the materials to have to withstand the radiation levels inside a fusion reactor. HFIR has high radiation levels internal to the reactor. So, you can put bits of material in there and measure how they perform and how they degrade over time as they are exposed to those very high radiation fields. And the final area, I would say it is an activation analysis. So that means if you want to understand really at a minute level, what is in a material, HFIR is very well placed to be able to detect really, really trace elements or trace amounts of elements which nobody else can see.

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JENNY: Given its world-class capabilities, visitors to the lab might be surprised by just how unassuming and simplistic the facility’s exterior is.

BRIAN WESTON: As you walk up to HFIR, it's a large white building, the sun sort of makes it shine. Very ’60s feel to the lettering over the door and everything -- High Flux Isotope Reactor.

MORGAN: That’s Brian Weston. He’s the division director of research reactors at ORNL.

WESTON: And as you walk in, you see a meter when you first walk in the door that tells you the power level and as good 1960s engineers would do, it's in logarithmic scale. So, it makes no sense to anybody except "Power’s on”. We go up the stairs, there are a number of stairs. It's three stories but feels like five. And when you get to the top, you're in the gallery. Our gallery is kind of an interesting place. To your right, you look out over the reactor bay, it's a high bay, you may see staff in there working dressed out in yellow anti-contamination clothing, but there's a there's a reactor pool, looks like a big swimming pool. It's a really deep, kind of startling blue color.

JENNY: The pool is divided into two parts. One side holds used containers of fuel – some of which emit a unique glow.

WESTON: Usually the last ones we took out are still glowing blue from the Cherenkov radiation, which is as I understand it, it's particles in the water going faster than light would go in water. And it's kind of a visual version of a sonic boom, that creates that blue glow -- looks kind of like the blue flame from gas.

MORGAN: The other side holds the heart of HFIR -- the reactor core. The core -- also known as the pressure vessel -- comprises a small fuel vessel that sits inside of a cylindrical chamber made of beryllium.

WESTON: The fuel itself is about 17 inches in diameter, about 2 feet high. It's about the size and shape of a beer keg, it's very small. But it produces the same amount of energy in the cycle as 8,000 tons of coal. It's kind of hard to imagine how compact it is. Around that is the beryllium reflector. The whole thing is under four feet in diameter, the real important part of the core.

JENNY: As you tour HFIR, you’ll see a model of the fuel vessel in the gallery overlooking the reactor pool. When you look inside, you see hundreds of thin metal plates lining the cylindrical container. These plates are the uranium fuel.

WESTON: The fuel itself has 540 fuel plates that have highly enriched uranium fuel, meaning that they're 93 percent uranium-235, which is much more. A power reactor is about three to four percent enriched, so it's high intensity. And that's to get the high flux, hence the name. In the center of the fuel is what we call the flux trap. It's about a six-inch diameter region where the highest neutron flux is, and there, we actually see 2.5 times 10 to the 15th neutrons per centimeter squared per second. So that's 2.5 million billion neutrons every second for every square centimeter, really intense flux. And that's what allows us to produce isotopes and do materials irradiations, and a lot of the world-leading science that HFIR is capable of.

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MORGAN: As we mentioned, HFIR makes a number of different isotopes that are used for a range of applications – from deep space exploration to life-saving medical treatments.

JENNY: Depending on what type of isotope you want to make, there’s a different recipe so-to-speak. The key ingredients include the target material – which consists of the element that you’re irradiating to make a certain isotope – and location of that material within the reactor. Different materials and different locations yield different results.

WESTON: Some of them are in the target basket, which is in the flux trap that I mentioned in the center. But we also have radiation locations out in the beryllium reflector around the outside of the fuel. And that's where we produce, for example, plutonium 238, which is, as you know, for the Mars space missions. Californium is a key isotope that we produce. So, we make 70 to 80 percent of the world's supply of californium. Californium is a neutron source, so you can use it to start up a new reactor, but it's also used for characterizing oil and coal. It's about a billion-dollar industry. So, it's a pretty significant product. We also produce a number of other isotopes -- selenium that's used for radiography. Nickel-63 is used for national security purposes – the machines in the airport that look for explosives or drugs on your luggage, they use a nickel-63.

MORGAN: HFIR also produces an isotope called actinium, which is making an impact on the lives of cancer patients.

DAVERN: HFIR is essential for the production of isotopes, particularly radioisotopes for research, for industrial applications, for the discovery of new elements, for space exploration – and for medical applications. The medical applications are really what my research is about and why I’m particularly interested in HFIR.

JENNY: That’s Sandra Davern. She’s the section head for radioisotope research and development at ORNL. She and her colleagues are leading the lab’s research on the medical uses for actinium.

MORGAN: Actinium is a radioactive isotope, also known as a radioisotope or radionuclide, which means it’s an unstable element that needs to expend energy to get to a stable state.

DAVERN: All they're trying to do is get to that stable state and how they get there is through different types of radiation that they emit. So, we have ways to create the environment in which these radioisotopes can be formed. And that requires HFIR, that requires high flux radiation of targets – that’s what we call them -- that contain specific either stable or unstable elements in them. They go through a conversion process and that conversion process changes them into other radioisotopes. And then there's a lot of separations chemistry required afterwards to extract the specific radioisotope we're interested in and get rid of all the other products that are produced in those reactions that become contaminants, because they're not what you're specifically looking for.

JENNY: There are different kinds of radiation that these radioisotopes emit. Sandra and her team are primarily interested in alpha emitters, like actinium. Alpha radiation comes from heavy isotopes and can only travel very short distances, making it attractive for medical applications.

DAVERN: Most of what we've been doing of late has focused on alpha-emitting radioisotopes, because there's huge potential in this particular type of radioisotope to treat cancer. And that has been sort of coming to the fore lately with the first FDA-approved drug, which is Xofigo, which is radium-223 dichloride, which is produced by Bayer pharmaceutical. And interestingly enough, the critical raw material for that product is produced in HFIR here at ORNL, and then we do the processing to send the parent isotope, which is actinium-227, to Bayer so that they can then harness the purification strategies to produce that drug compound that gets used to treat patients, and the patients that are treated with radium-223 dichloride have extensive bone metastases resulting from prostate cancer.

MORGAN: Currently, this treatment is used as a palliative therapy, but Sandra and her colleagues are looking to expand the use of alpha emitters to treat a range of cancers.

DAVERN: We do see that using alpha emitters such as radium has really huge potential, if you can treat patients earlier in their stage of disease. So, what we're trying to do is get to a place where alpha targeted alpha therapy and targeted radionuclide therapy become more integrated into the treatment regimen for patients. And this is going to be particularly important for treating patients who have cancers that are resistant to other drugs, for people who have really no other good recourse to treatment, and also for treating the types of cancers that can't be treated well with external beam radiation because the tumor’s potentially too close to an important organ to radiate. And in those instances, the chemo and the immunotherapy approaches have probably failed. I really think this work is so important because of the hope we can give to people who have of run out of options.

JENNY: ORNL also produces alpha emitting actinium-225, which is currently being used in clinical trials and is likely to become the next FDA-approved cancer treatment.

MORGAN: This treatment could yield highly targeted ways to treat cancer, which minimize damage to healthy tissue in the body.

DAVERN: And it's targeting a wide range of cancers, everything from neuroendocrine tumors to lung tumors to ovarian cancer, and breast cancer. And really, in a lot of ways, this kind of treatment is tumor and cancer agnostic. So, it doesn't matter what the tumor or cancer is, as long as you can find some sort of a targeting molecule that will recognize unique signatures on cancer cells. And why that's important is you use those molecules as a way to carry your radionuclide. So, the actinium-225 or the radium-233 to that site. And then you radiate only those cancer cells, because the range of effect of the alpha emitting radionuclides is on the order of 10 cells. So, you're not going to do much damage to surrounding healthy tissue, it's going to be very minimal, you're going to contain the radiation where you want it to be. And that's really the power of this type of treatment. And I think why the world is excited about it. And why this, we see this as the next sort of advance in in treating cancer. And it's exciting that HFIR and ORNL have a huge part to play,  in making sure that there are enough of these radionuclides to treat patients, once it becomes more routinely accepted as a treatment.

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JENNY: HFIR is also home to one of the most powerful techniques to explore the internal properties of a material at the atomic scale – neutron scattering.

MORGAN: Neutrons have no electrical charge, which allows them to easily and safely pass through a sample, revealing information about the material’s structure and properties.

JENNY: Interestingly enough, neutron scattering was actually pioneered at ORNL in the late 1940s – using a different nuclear reactor.

MORGAN: Physicists Clifford Shull and Ernest Wollan discovered this powerful research technique using the Graphite Reactor, which was originally built for the Manhattan Project during World War II. Shull would go on to win a Nobel Prize for his contributions in 1994.

JENNY: Since then, neutron scattering has become an invaluable tool for materials research, as it can give insights into how atoms are arranged, how they're held together and how they're moving around.

MORGAN: At HFIR, the neutrons created in the reactor’s core are funneled out through horizontal beam tubes, which originate from the beryllium reflector that houses the fuel element. These tubes lead to another part of the facility where the neutron scattering experiments take place.

BRYAN CHAKOUMAKOS: My office overlooks the reactor building across the street, and it looks like any other building that might have some kind of industrial operation, you wouldn't know that there's a nuclear reactor in there. But when you go in and go down to the ground floor, where the instruments are, you know you're in a special place.

JENNY: That’s Bryan Chakoumakos. He’s a corporate fellow at the lab and is a group leader for single crystal neutron diffraction.

MORGAN: There are 12 instruments on several beam lines that researchers can use for a range of scattering experiments.

JENNY: Each instrument serves a different purpose, depending on what is being studied, but they all receive the beam from the reactor and pass it through a sample material for analysis.

CHAKOUMAKOS: What's interesting about our facility is old, but it's still going on for many years to come, is that all the beams are open, all the instrument designs are open, so that they can accommodate complex apparatus to control the environment of the sample that we're studying, which could be a solid, a liquid, or even a gas. And so, the beams actually go through the air. And so, that’s a lot of signs and barriers to prevent people from intruding on them. And there's lots of safety training associated with that. But that's one of the things that will strike you as you go through the beam room. And then into the newer guide hall that also has more modern looking instruments, but still with open flight paths, and the ability to study materials at extreme conditions.

JENNY: While the open beam path may be a little old school, the instruments receiving the neutron beams are anything but.

CHAKOUMAKOS: And oftentimes, you won't see anybody in these areas, because most of the equipment is automated. They're like robots, they're designed to once the sample is mounted, and a program is scripted to collect the information that's being sought. You don't have to stay there in that noisy space, you can go back to your office, and it's all done automatically. And experiments can take from a few hours to a few days.

JENNY: HFIR is one of two neutron scattering facilities at ORNL. The other is the Spallation Neutron Source, or SNS.

MORGAN: SNS is an accelerator-based neutron source that came online in 2006. The beam created in the accelerator is channeled to 19 specialized instruments.

JENNY: The different designs and instruments of the two sister facilities give researchers the opportunity to harness their unique but complementary capabilities.

CHAKOUMAKOS: In terms of doing neutron scattering experiments, HFIR special in the sense it has these open instrument design. So, we can put in complex sample environments to make high magnetic fields or high temperature, ultra-low temperature much more easily than you can say at the Spallation Source.

MORGAN: The ultra-low temperatures HFIR is capable of come from its cold source, which was added in 2007. Here’s Brian Weston again.

WESTON: We've had scattering for a long time, but that's where we put a moderator vessel up inside one of those beam tubes I mentioned. So, we're actually pumping 20-degree Kelvin, supercritical liquid hydrogen up into the core. It's not something you do at most reactors. So, there are others but not many.

JENNY: In fact, everything we use, from technological devices to shampoo to antiviral drugs to cement, benefits from this kind of research capability.
 

CHAKOUMAKOS: The reactor produces a broad spectrum of neutron energies or wavelengths. And we can shift that spectrum to say longer wavelengths by what we say moderating the neutron energies. So, we do that by putting in what's called a moderator, a cold source, near the reactor core. And the neutrons that bounce around in that moderator then lose energy and shift the spectrum of energy to longer wavelengths or lower energies. And for some types of instrumentation, or measurements, longer wavelengths are more advantageous, particularly things studied like long, large-scale structures, like polymers, plastics, surfactants, are better studied with longer wavelengths, also proteins.

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MORGAN: HFIR is one of the U.S. Department of Energy’s Office of Science user facilities, which give scientists from around the globe access to cutting-edge research tools.

JENNY: Each year, HFIR welcomes hundreds of scientists and engineers from academia, industry and other government laboratories who use the reactor for their research.

MORGAN: Collin Broholm is one of those visitors. He’s a professor of physics and astronomy at Johns Hopkins University.

JENNY: Collin and his colleagues have used HFIR several times over the years. His first experiment at the facility was in 1995 and resulted in frustration – but not the kind you may think.

BROHOLM: We’ve been interested in something that we call the frustrated magnet. And maybe it's best to understand the counterpart, which is a material that is magnetic, and where the interactions between the atomic-scale magnetic moments that form actually can happily arrange themselves in a condition that is, that is energetically favorable. But then there's some materials actually where this is not the case. And so there are magnetic atoms in these materials. And they do interact. But because of the geometry of the material, it's not possible to achieve a sort of energetically favorable state.

And I can give you an example, if I have three, three magnetic atoms sitting on the vertices of a triangle, and they all would like to be anti-parallel to the nearest neighbors, then I can't really do that, because once two of them had decided to be anti-parallel, then then the third one has either violate the condition with respect to one or the other side. And so we call it frustration. And there are all sorts of interesting parallels to human experience.

MORGAN: Collin had been conducting experiments on these types of materials at a nearby research reactor in Maryland, when he ran into some additional roadblocks.

BROHOLM: We were looking at materials over the years that are frustrated to try to understand what we call collective physics because it has to do with many, many, many electronic degrees of freedom into plane. And particularly, there was a problem we had with one of these materials, which was vanadium oxide. So it's a fairly, in principle fairly simple material. But there was some aspects of it, we just couldn't really fully resolve using the local instrumentation. And so we went to Oak Ridge. And that was my first experiment there. And I was very impressed by the, like the quality of the data that actually could come out from that.

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MORGAN: To help develop the next generation of neutron scattering users like Collin, ORNL also gives graduate students the opportunity to use the facility to learn about using neutrons in their research through the National School on Neutron and X-ray Scattering.

JENNY: The program began in 1998 and has been jointly hosted by ORNL and Argonne National Laboratory since 2008. Students spend a week at ORNL conducting neutron scattering experiments at HFIR and the Spallation Neutron Source, and then they travel to Argonne for time at the Advanced Photon Source, another DOE user facility.

MORGAN: Bryan Chakoumakos has been involved in the school for years and served as the local director for a decade.

CHAKOUMAKOS: It's our biggest outreach effort. We would take in about 60 graduate students from across the U.S., and now includes Canada, every year, to train them in all types of neutron scattering methodology, both theory and practice, with hands on demonstration experiments. And it's a pretty novel thing. There are other places in the world where they do this, and it's quite effective way to train the next generation of users. And what you'll find is that a lot of our staff actually went through NXS school in years past. So it really does create a new generation and a better in-depth understanding, not just to complete your thesis, but usually those people come back as users of our facility or end up as faculty, and then their students come and use the facility. So, it has a lot of value, and it is really proven successful.

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JENNY: As you’ve heard, HFIR is incredibly versatile, but did you know that it can also help solve murder mysteries?

MORGAN: I bet you didn’t see that one coming, did you? Just how could a nuclear reactor possibly be used for forensics?

JENNY: Well, the answer is neutron activation analysis -- which is an extremely sensitive technique used to determine the existence and quantities of major, minor and trace elements in a sample material.

MORGAN: Here’s Brian Weston.

WESTON: We can insert capsules into the core, we have a pneumatic tube, so you can do it during operation. So, you just put materials in the core. And when they come out, they generate a spectrum. And you can read that and see, okay, what elements are in here. And there are about 65 different elements you can see that way. And depending on the element from parts per million or billion, or in some cases, parts per trillion, really tiny amounts you can see.

JENNY: In 1850, President Zachary Taylor died after only being in office a mere 16 months. Since his death, there have been several theories of what could have caused the president’s sudden demise. Everything from a stomach bug to assassination.

WESTON: So, there was a theory back in the early 90s, that President Zachary Taylor had been poisoned by arsenic. And they actually convinced the family to exhume the body. And we still have the, we still have the little samples of the fingernail, and the hair samples that they took. But we were able to insert those into the neutron activation analysis facility and quickly found that the levels of arsenic in his body were normal. So, months later, other different laboratories across the country did their own analyses and everybody agreed to that.

MORGAN: With poisoning officially ruled out, just what was the culprit?

WESTON: What they think actually happened is he went to a to a fundraiser for the Washington Monument. And while he was there, he had raw cherries and milk. And, well, raw cherries isn't unusual, but raw milk, and he just got some, you know, stomach issues that were not, that were hard on him. And probably what was even harder was that cutting edge 1850s medical technology as the doctor tried to help him. And ultimately, that's what got him. He just was, you know, dehydration and complications from that. Nothing quite as exciting as arsenic. But that's an example. That's sort of criminal forensics. But you know, forensics is one of the things that neutron activation analysis is useful for. And again, the high flux means we have one of the more sensitive facilities in the world for that.

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JENNY: HFIR may be nearing its 60^th anniversary, but there are no plans to retire the research reactor anytime soon.

MORGAN: One of the keys to HFIR’s longevity has been how well it’s been maintained over the years. We talked to Ken Andersen about a series of upgrades that are on the horizon, which will ensure it runs for decades and decades to come.

ANDERSEN: We have quite a number of things that we would like to do at HFIR and a number of things we have to do. One of them is replacing the beryllium reflector. That's the component that sits immediately around the fuel element in HFIR. It’s the element that gives rise to the very high flux of neutrons, behind the name of HFIR.  It reflects the neutrons back into the core so that when you put stuff in there to be irradiated or when you put neutron beams in there to extract them, you get the highest possible flux. That beryllium reflector gets damaged with by radiation and every 20 years or so it has to be replaced. That’s happening in the next five years from now, roughly, we are going to have an outage of the reactor in order to pull out the existing beryllium reflector, which will have reached its end of life by then. And we're going to replace it with a new one, which will be modified so as to improve the isotope production capabilities. And there will also be some tweaks which will improve some of the neutron scattering performance. That's really a maintenance activity. It’s something that has to be done otherwise HFIR couldn’t continue operating. At the same time, there are a number of improvements that we would like to make to the neutron scattering facilities at HFIR.

JENNY: Replacing the beryllium reflector is no easy task, but the next upgrade will be HFIR’s biggest overhaul yet.

ANDERSEN: The other big thing is the replacement of the pressure vessel. Now that's an original component, it's the vessel which houses the cooling, and the shielding water if you like, of the reactor. It was installed back in the 1960s. It is the original component; it is the ultimately, it's a lifetime limiting component of HFIR. If we want HFIR to continue operating for many decades to come, that is a component that we that must be replaced. That then sets us up to continue to operate HFIR basically until the end of the century.

MORGAN: These upgrades mean that scientists like Collin Broholm who rely on HFIR will be able to continue a long legacy of world-leading materials research.

BROHOLM: The role of Oak Ridge National Lab in the development of neutron scattering is, is really from the very beginning, the first concept of using neutrons to study materials really came from Oak Ridge National Lab. So that's a long, long tradition for this that's recognized and understood in the, in the community of scientists who use these methods. Think about it for people outside of the field, maybe it feels a bit surprising that one should use a neutron facility to probe materials. But it turns out that there are some things that we actually cannot learn about materials without using the neutron scattering method, you could think of the neutron as being sort of a messenger that comes into the material and leaves carrying information about what happens at the atomic scale inside the materials. And so there's really some areas of materials-based science that we just cannot make any progress without using these kinds of methods. I think it's recognized now that the capabilities that we have at the HFIR facility will continue to be important into the future and that there's actually great potential for enhancing the service that it can provide to the scientific community. It's been a long and storied career of scientific contributions from HFIR, but the story is by no means ending.

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JENNY: Thank you for listening to this episode of The Sound of Science.

MORGAN: If you enjoyed this episode, please leave us a review wherever you get your podcasts.

JENNY: If you’re interested in following the latest news about HFIR and neutron sciences from ORNL, follow @ORNLneutrons on Twitter and Instagram.