ORNL mines Pm-147 from plutonium by-products

The process: The ORNL efforts are tied to the Pu-238 production schedule, which is currently between two and four processing cycles a year. It is estimated that there are hundreds of curies of Pm-147 in each batch. Working in around-the-clock shifts for several days, the project team uses hot cells in ORNL’s Radiochemical Engineering Development Center (REDC) to isolate a concentrated batch of Pm-147 from the solution of Pu-238 byproducts.

That batch is then transferred into a shielded cave at the REDC, where it is purified and readied for shipment to DOE Isotope Program customers. The process involves a few months of effort and around 20 people.

The team will spend the next year demonstrating whether the recovery of Pm-147 from Pu-238 by-products is sustainable. If so, the project should grow alongside the Pu-238 program. The lab’s goal is to produce enough Pu-238 to yield 1.5 kilograms of plutonium oxide annually to meet NASA’s demands for deep space travel.

“Currently, we’re the only producers of Pm-147 in the U.S., and there’s a market for it,” Mayes said. Research indicates it could have additional applications in medical imaging and as a radioisotope to generate power for space probes.

The program: While the Pu-238 Supply Program is funded by NASA and managed through DOE’s Office of Nuclear Energy, the recovery of Pm-147 is funded by the DOE Isotope Program within the DOE’s Office of Science.

Pm-147 is one of about a dozen elements the DOE is looking to mine from the Pu-238 production waste stream. Successful efforts with Pm-147 may lead to the extraction of other materials at ORNL, Mayes said.