MU Research Reactor prepares for production of radioisotope

COLUMBIA – With shutdowns in reactors that produce Molybdenum-99 around the globe, the staff at the MU Research Reactor continues its quest to develop a processing center for the radioisotope.

Mo-99, a radioactive isotope used in medical imaging procedures and radiopharmaceuticals, currently is not produced in the U.S. With the shutdown of facilities that were producing the radioisotope in Belgium, Canada and the Netherlands, there has been a shortage of Mo-99, limiting the capabilities for hospitals to diagnose and treat cancer patients.

Technical problems and maintenance closures of aging reactors means hospitals have been receiving a fraction of their usual supply.

The staff of the MU research reactor, the nation’s most powerful research reactor among university campuses, is working to make the reactor the first domestic producer of Mo-99.

The move is being supported by the medical community. The March issue of Imaging Economics reports that industry activists will lobby Congress for an upgrade to the research reactor.

“It is vitally important to the patients in the U.S. and the U.S. medical community that we do everything to expedite the process for creating Mo-99,” said Ralph Butler, director of the research reactor. “Probably four years from now, we will be able to supply the U.S. market. We have to design and build a new building for extracting the Mo-99 from irradiated targets.”

Originally, the cost estimate for creating the processing center was $40 million. However, the staff of the reactor has been working with INVAP, an engineering design company in Argentina, to prepare a conceptual design draft. The estimate has risen to $50 million — $40 million for the building itself and $10 million in other supplies needed for the center.

In October, the staff at the reactor did a test run building the radioisotope and they are preparing to do a second test demonstration in April or May.

Ken Brooks, associate director of the research reactor, said they are looking for more information regarding the creation of Mo-99 in the second demonstration.

"We expect the second round of testing to provide further information regarding Mo-99 yield and to benefit from some process enhancements implemented after round one that will streamline the time involved and provide even more detailed yield data," Brooks said.

Testing involves low-enriched uranium target material being positioned near the reactor core for a week and then removed for processing and analysis.

"The main purpose of the initial testing is to assess the yields of Mo-99 achieved through our irradiation of low-enriched uranium target material," Brooks said via e-mail. "Lots of theoretical calculations have been done, but ultimately they have to be proven through testing."

The development of Mo-99 also allows for more research opportunities that can arise when extracting the radioisotope.

“This will increase the ability to do medical trials and do more research, which could lead to new cancer treatment,” Butler said. “Scientists have been having to go to Australia to do some of this research because it’s just not available in the U.S.”

According to the MU reactor Web site, its scientists have developed three FDA approved radiopharmaceutical agents: Ceretec, the first brain imaging agent; TheraSphere, a treatment for liver cancer; and Quadramet, an agent designed to relieve pain from metastatic bone cancer.

The MU reactor will extract Mo-99 and a few other isotopes, and the rest of the material from the process will be delivered to the Department of Energy for proper disposal.

The importance of the development of the processing center continues to be urgent when considering that the current developers of Mo-99 are experiencing problems with their machines.

The High Flux Reactor at Petten, in the Netherlands, recently was given permission to start up again temporarily for a year after being shut down since August.

Combined with Canada's reactor, which also has experienced an extended shutdown, these two reactors make 80 percent of the world’s supply of Mo-99, according to Butler.

Butler said the MU Research Reactor wouldn’t have these types of problems. He added the machinery in the current producers’ reactors is hard to maintain because the machines are old, very large and complex.

“That’s the advantage the reactor here has,” Butler said. “We are a smaller reactor and don’t have the complex machinery. We don’t have the maintenance issues these foreign reactors have. It takes a lot of money to keep them running.”

Butler said the plan is to provide the majority of the U.S. supply of Mo-99 once the new facility is up and running.

“We have plans to supply at a minimum, 50 percent of the U.S. need,” Butler said. “So the facility will be scaled to accommodate much more. Just big enough to do this, but not too big.”