Published on Show Me Mizzou Dec. 19, 2024
Story by Chris Blose, MA ’03
NextGen MURR. The University of Missouri’s bold leap in nuclear science will be a 20-megawatt reactor set to transform cancer treatment. It will more than triple isotope production to meet growing demand. It will build on MURR’s legacy as the most powerful U.S. university reactor, one that has run nearly nonstop since 1966. It will multiply MURR’s impact as the only source in the Western Hemisphere for four essential cancer-fighting isotopes, responsible for 9.5 million months of extended life annually. That’s in addition to breakthroughs in medicine, archaeology and beyond, and a true crime twist: NextGen MURR will also be a forensics powerhouse.
What do the following have in common?
Radioisotopes that treat more than 1.6 million cancer patients per year. Forensic analysis that affects the outcome of criminal trials. Novel medical devices designed to target disease while leaving healthy tissue alone. Research that determines the often-surprising origins of cultural artifacts thousands of years old.
If you guessed, “They all happen at Mizzou,” you get partial credit. More specifically, they all happen at one location at Mizzou: the University of Missouri Research Reactor (MURR).
Since its first nuclear chain reaction in 1966, MURR has been the home to abundant discoveries in radiopharmacology, archaeometry, trace element epidemiology and materials science. (See “From Atoms for Peace to New Nuclear” below.) At 10 MW, it’s the most powerful research reactor at any university in the country — and has been so since 1974.
But times change, and so does demand. In 2023, the university announced plans for NextGen MURR, a new 20 MW research reactor that, when running in tandem with MURR, could more than triple capacity for producing radioisotopes used in cancer treatment and expand research capabilities in other fields.
“We have a responsibility to look beyond just today and to try to forecast what is going to be needed, and demanded, of us in the future,” says Michael Hoehn II, who became NextGen MURR’s inaugural program director this year. (See “NextGen MURR’s true son” below.)
For example, today MURR is the sole U.S. producer of four medical radioisotopes used in cancer treatment: Iridium-192 helps treat brain, breast, cervical, head and neck, prostate, skin, lung and gynecological cancers. Lutetium-177 currently is used to treat prostate cancer and neuroendocrine tumors, with more possible targeted treatments in the future. Sodium Iodide-131 is used for diagnosing and treating thyroid cancer and hyperthyroidism. And Yttrium-90 targets liver cancer.
That’s four as of 2024, but Hoehn notes that there are thousands of clinical trials in process involving other isotopes. The ones that prove effective and reach bedsides will drastically increase demand. In Hoehn’s view, Mizzou has the track record of success and safety to produce them right here.
A new view of nuclear
Thousands of Columbia residents drive past MURR while commuting on Providence Road every day without realizing they’re passing a nuclear reactor. Hoehn says it’s likely more people know the MURR name internationally than locally.
“When you say MURR in the radioisotope community and the medical community, they understand the importance of it to the supply chain for radioisotopes,” Hoehn says. “But there are people here who don’t know why Reactor Field is named what it is, or the Reactor Bus Loop, and they don’t know there’s a reactor there. We need to change that.”
MURR’s accomplishments are impressive enough to warrant more attention. The most obvious example, given how many cancer patients they affect, are the radioisotopes the reactor produces. On top of making them, MURR researchers also have been part of teams developing novel delivery approaches, such as TheraSphere, a special medical device now owned by Boston Scientific. TheraSphere consists of tiny spheres of glass that deliver Yttrium-90 to the liver — a targeted approach that is designed to destroy cancer cells while sparing healthy tissue as much as possible. Such targeted therapeutics are becoming more common, which is part of why Hoehn sees such an urgent need for NextGen MURR.
MURR and its future counterpart cover a wide range of fields beyond radiopharmaceuticals, notes John Brockman, associate director of research and education for the reactor. Brockman points to the MURR Archaeometry Laboratory, first established in 1988 and continuously funded by the National Science Foundation ever since, a true rarity among labs.
Archaeometrists at MURR primarily use a technique called neutron activation analysis to examine archeological artifacts. “They perform what are called provenance studies,” Brockman says, meaning they’re trying to determine everything from age to origins of the objects. Neutron activation analysis and other more recent techniques such as X-ray fluorescence allow them to examine materials without destroying them. By studying the elemental composition of such objects, archaeometry can trace the origins of raw materials, revealing ancient trade routes and pinpointing the original locations of various cultures.
Brockman and other MURR-affiliated researchers use similar techniques in what’s called trace element epidemiology, a field that uses nuclear analysis to study medical issues, among other things. For instance, he has been a part of teams examining various bodily samples — blood, plasma, urine, hair, even toenails — to determine how certain metals in the diet affect health, such as the connection between selenium and cancer risk.
“Often these samples were collected 20 years, 30 years in the past,” Brockman says. “They’re irreplaceable.” The ability to accurately analyze such samples while maintaining their integrity sets nuclear science apart.
MURR sets itself apart, too, with both the diversity of work and its far-above-average operating capacity. But Hoehn foresees an even higher goal.
“Our vision right now is to be the leader in radioisotope production, nuclear science and technology research in the Western Hemisphere,” Hoehn says. “Once NextGen MURR comes online, there’s no reason why we can’t do it.”
The nuclear family of faculty
The vision is for NextGen MURR to be a fully integrated nuclear campus located at Discovery Ridge southeast of town.
“We see this as not just the reactor,” Hoehn says, “but as the ability to partner with the private sector, the radiopharmaceutical companies, maybe the government in various national labs in a research setting — and not just in a traditional partnership sense, but on-site in that integrated ecosystem.”
As the process shakes out over an estimated eight to 10 years, Hoehn will work with a design-and-build partner to ensure that vision comes to life, with spaces not only for faculty labs and the highly specialized equipment that supports them, but also potential startup housing or special labs for future government agency partnerships.
“You can think about interactions that create inspired research in a model like this,” Brockman says. “You can think about on-site partners designing research with our specific researchers and their expertise in mind.” Both Brockman and Hoehn point to the powerful possibility of taking a basic scientific discovery all the way to a patient’s bedside treatment, and doing so all in one place. That’s a more likely outcome when you gather all the right expertise — from nuclear science to the management of clinical trials — in one location.
If a carefully planned critical mass of talent is one benefit of NextGen MURR, added power is another. A 20 MW reactor on top of its existing 10 MW one would give Mizzou the two most powerful university research reactors in the country. (For reference, the Ameren Callaway nuclear power plant, where Hoehn worked for 18 years, is 3,565 MW. It takes much more power to produce electricity than to perform research.)
That power is not a one-to-one translation, since NextGen MURR will be designed with current best practices in mind. That’s why Hoehn and others say it will “more than” triple Mizzou’s current capacity.
One of the key advantages of this increased power is the boost in neutron flux, which refers to the number of neutrons passing over an area at a given time. At present, MURR can retrieve isotopes from the reactor’s central “flux trap” positions only once a week, when the reactor shuts down on Sundays. NextGen MURR’s design will not only increase the neutron flux and number of isotopes created, but also it will allow researchers to access and remove isotopes safely while the reactor continues to run. The process has major implications for productivity.
So does the range of up-to-date tools and techniques envisioned for NextGen MURR. The goal is to create a hub that will improve and save lives in the state, country and beyond — and recruit and retain even more experts aligned with that goal. “NextGen MURR will attract the best and the brightest from around the world,” Hoehn says. “To be able to have that right here in Columbia, Missouri, is amazing.”
NextGen MURR’s True Son
On a crisp fall Saturday in Columbia, you’ll find Michael Hoehn II decked out in black and gold in the stands at Faurot Field, where he joins his voice with 60,000-plus other Tiger fans.
On a weekday, you’ll find him not far away at Reactor Field at MURR, where he uses his voice to extol the possibilities of nuclear research for the people of Missouri, the country and the world.
Hoehn is a True Son, born and raised in Saint Charles. He earned a bachelor’s degree in mechanical engineering at Mizzou and an MBA from Maryville University, then spent 18 years in nuclear energy at Ameren Missouri’s Callaway Energy Center.
“I was helping to provide energy to the public in a clean, reliable manner, so I took that role pretty seriously,” Hoehn says, “and I took a lot of pride in knowing what my job was.” He became director of nuclear engineering design and projects, a role that included everything from managing major changes to juggling project timelines and budgets.
When NextGen MURR was announced in 2023, Hoehn found the perfect fit for his Mizzou pride and nuclear know-how — and it was right there in the town where he was already raising his family. He pursued and was named to the role of inaugural program director for NextGen MURR, reporting to the executive director of MURR, Matt Sanford.
Hoehn is responsible for assembling and leading a team of designers, engineers and other experts. He oversees the process of choosing a long-term design and construction partner for what is envisioned as an integrated nuclear campus. As the project moves forward, he’ll also be responsible for keeping the project on track through approximately eight to 10 years of various reviews and the construction process before it comes online.
Hoehn and team draw on nearly 60 years of learning at MURR, but they’re also taking lessons from friendly competitors abroad. “We were at a new reactor build site in the Netherlands recently doing benchmarking,” he says. “That site has integrated radiopharmaceutical production capabilities as well as envisioning an integrated medical campus with clinical trial capabilities, and they’re going to have a brand new state-of-the-art-reactor.” In other words, it was exactly the sort of model he has in mind for NextGen MURR.
He also owns his role as a cheerleader for NextGen MURR. Having worked in nuclear energy for so long, he’s seen what a lack of education and information can do to public perception. So he works to educate, even evangelize. He’ll tell you about the obvious benefits of radiopharmaceuticals for treating cancer — and how they are improving via better targeting techniques that kill a tumor while saving healthy tissue. He’ll discuss materials research, including improving increasingly critical items such as lithium-based batteries. He’ll mention the value of trace-element epidemiology, and how advanced neutron scattering capabilities will attract the best of the best researchers.
“We should be talking about our ability to improve lives,” he says. “That should be fundamental to our discussion about the power of the neutron and what we’re doing every single day here, and what we envision expanding at NextGen MURR.”
MURR timeline: from Atoms for Peace to new nuclear
1953: President Dwight D. Eisenhower delivers his “Atoms for Peace” speech at the United Nations, in which he covers nuclear disarmament and the positive possibilities of atomic research.
1955: University of Missouri president Elmer Ellis polls faculty and staff about a possible research reactor. The answer is a resounding “Yes.”
1959: Ardath Emmons becomes MURR’s first director.
1966: MURR officially comes to life, launching its first sustained chain reaction on Oct. 13, a pivotal milestone in research.
1970: MURR researcher George Leddicotte applies neutron activation analysis in courtroom testimony for the first time.
1974: MURR upgrades from 5 MW to 10 MW. A half-century later, it remains the highest-power research reactor at a U.S. university.
1976: MURR begins producing Iridium-192, used in high-dose radiation therapy to treat numerous types of cancer.
1986: MURR helps analyze the faulty O-Rings involved in the Space Shuttle
Challenger explosion.
1986: Experiments begin for what will become two new cancer treatments, Quadramet and TheraSphere.
1988: The MURR Archaeometry Laboratory opens. It has received continuous National Science Foundation funding for 36 years.
2002: MURR expands by 6,000 square feet to allow for increased radioisotope production, among other benefits.
2007: Researchers analyze selenium (and other element) levels in toenail samples to help determine dietary effects on cancer, heart disease and other conditions.
2016: MURR receives the Nuclear Historic Landmark Award from the American Nuclear Society.
2022: Lutetium-177, a radioisotope produced exclusively at MURR to treat prostate cancer, receives FDA approval.
2023: NextGen MURR announced. Slated to open in eight to 10 years, it has the potential to triple the capacity in nuclear research and
isotope production.
Click here for more on the medical isotopes MURR produces for cancer diagnosis and treatment.
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