How many missions could a drone or satellite fly with a battery pack that can last decades? And what if that battery could be fueled by nuclear waste?
That’s the future scientists are working toward in DARPA’s “Rads to Watts” program, which aims to create lightweight batteries with a high energy density. And a recent $3.37 million contract award aims to fund a viable proof-of-concept device that can produce more than 10 watts per kilogram with a yearslong shelf life.
“Solar cells directly convert sunlight into electricity…Ours directly convert radiation into electricity,” said Stafford Sheehan, CEO and founder of Project Omega, which describes their radioisotope power sources as mini-generators that replace traditional batteries.
“We already have some of these small devices running; the ones that are specifically designed to meet the DARPA figure of merit are going to come out early next year.”
Several organizations are participating in the program, with Morgan State University serving as the prime contractor and handling basic research and the Pacific Northwest National Laboratory handling nuclear materials and testing. Northrop Grumman and ARA will bring computational modeling to make sure the prototype meets performance standards.
Project Omega will build the nuclear power generator based on a radioisotope found in nuclear waste, and Widetronix is designing the semiconductor power converter. The goal is to produce a working prototype by early 2027 at the Pacific Northwest National Laboratory.
The power cells could be used in “any application where a battery dying is a pain point,” Sheehan said. “One example is on satellites: if you lose power on a satellite, you lose the satellite, it’s gone…if your batteries die and you don’t have any sort of backup power.”
These power sources use isotopes separated from nuclear waste and convert radiation directly into electricity.
“At a high level, we take nuclear waste, we recycle it into two products: one is fuel for reactors…the other are power isotopes, so isotopes you can use to power things,” Sheehan said.
Radioisotope power sources have been used in everything from smoke detectors to space systems. But Project Omega hopes to do it on a larger scale.
“There are over 100,000 metric tons of nuclear waste sitting in the 52 reactor sites around the country; so there’s plenty of nuclear waste currently. The federal government gets sued for billions of dollars every year just because they haven’t dealt with the nuclear waste,” Sheehan said. “It’s very valuable to have a battery that lasts.”
Omega’s power cells consist of a solid state, or “chunk,” of isotope that will be layered with the semiconductor to generate power. They also work in extreme temperatures—something that would benefit military operations using unmanned systems in harsh environments.
“We have been using these radioisotope power systems in space for decades,” Sheehan said. “We’re just taking the systems that we use for space and we’re using a different isotope,” Strontinum-90, which is less hazardous than the Plutonium-238 isotopes used in similar systems.
The award comes as the Pentagon grapples with increased demand and use of drone systems
that have to be charged and the persistent need for more power generation on the battlefield.
“Over the next 18 months, the program will focus on reducing technical risk, testing system performance under realistic conditions, and generating the data needed to inform future development and transition pathways,” a PNNL official wrote in a statement to Defense One. “Key challenges include improving energy conversion efficiency, validating long-term reliability, managing radiation effects, and ensuring safe, secure handling and deployment.”
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