Chalk River Laboratories, National Research Universal Reactor. Source: Atomic Energy of Canada Limited

The search for a domestic supply of the radioisotope technetium-99m (tech-99) may have to begin anew as General Electric has temporarily put the brakes on a project at an Illinois nuclear power plant that would have produced molybdenum-99 (Mo-99), which decays into tech-99.

GE Hitachi Nuclear Energy (GEH) had been working with Exelon, an Illinois electric company, to produce Mo-99 at the Clinton Power Station, a nuclear power plant in Clinton, Ill. They were working on a design to allow the removal of activated Mo-99 on a weekly basis.

But now, the project has been put on hold as financial projections for Mo-99 production “do not support the remaining cost,” GE said in a statement. Completed work on the project will be retained by the company’s engineering staff, and as current reactors that produce Mo-99 are taken out of service, GEH will “re-examine the viability” of continuing with the project, concluded the statement from GE.

About 95 percent of the world’s Mo-99 is produced by five nuclear reactors, with the largest share belonging to the National Research Universal (NRU) reactor in Chalk River, Ontario. The past few years have been marked by shortages in the supply of Mo-99, and the problem was exacerbated by disruptions at the NRU reactor. Last year, the Chalk River facility experienced a month-long shutdown for inspections, but the Canadian Nuclear Safety Commission announced last fall it would renew the reactor’s operating license for another five years, until Oct. 31, 2016.

Recent disruptions at the Chalk River reactor underscore the fragility of the U.S. supply chain for Mo-99, according to Andrew J. Einstein, MD, PhD, assistant professor of clinical medicine at Columbia University Medical Center in New York City.

“So long as our current supply is existent and reliable, I don’t think [GE’s] decision will have any impact on nuclear medicine studies in the U.S., but of course people working in the field have our eyes looking down the road past 2016 when the major American source of Mo-99, namely the Chalk River reactor, will presumably go offline,” Einstein said in an interview.

Einstein said he hopes that GE’s decision doesn’t reflect an environment that makes it financially infeasible for other interested parties to develop sources of Mo-99. Federal legislation such as the Senate’s American Medical Isotopes Production Act of 2011 would be useful in spurring development of a domestic source of Mo-99, he said.

Tech-99 is used in approximately 85 percent of nuclear medicine diagnostic imaging procedures.