US turns decades-old radioactive waste into nuclear power technology that could keep underwater drones running for nearly 30 years

The United States is exploring an unusual way to power the next generation of underwater technology. It is turning radioactive material that has spent decades in government storage into long-lasting electricity.

At the heart of the effort is strontium-90, a radioactive by-product that can produce heat as it naturally decays. That heat can be converted into electricity, potentially allowing power systems to operate for years without cables, fuel deliveries or frequent maintenance.

Washington and Seattle-based Zeno Power is developing the technology for both defence and space applications, with the Pentagon backing a project that could eventually place nuclear-powered energy nodes on the ocean floor.


ALSO READ: Google Drive is ending Google Photos backups on August 10

From Oak Ridge waste to a new nuclear power source

The strontium-90 being used isn't newly produced material and it comes from a BUP-500 radioisotope thermoelectric generator built at Oak Ridge National Laboratory in the mid-1980s. The device was never deployed and remained in storage for nearly four decades. The US Department of Energy had expected the material to remain there for decades longer before disposal.

ALSO READ: Snap co-founder Evan Spiegel and Miranda Kerr donate millions to erase $550 million in medical debt for 261,000 Californians, following Jeff Bezos' ex-wife MacKenzie Scott’s model

Instead, Zeno Power is recycling the material into fuel for its radioisotope power systems. The move also helps the government clean up a facility scheduled for demolition while avoiding some of the costs and liabilities associated with conventional disposal.

OREM Manager Jay Mullis described the arrangement as "a win-win scenario that's removing a significant source of radioactivity" while saving taxpayers money and supporting nuclear innovation.

ALSO READ: Mark Zuckerberg’s $300 million yacht Launchpad was nearby as Alaska cruise ship rescued stranded skiff after it ran out of fuel. Meta CEO explains why yacht did not respond immediately

Pentagon wants nuclear power on the ocean floor

In October 2023, Zeno Power received a $7.5 million US Department of Defence contract to develop and demonstrate a radioisotope power system designed to provide resilient power on the seabed.

The project falls under the Pentagon's Distributed Energy Provided Throughout the Seas, or DEPTHS, programme. The concept is strikingly simple: instead of repeatedly sending ships to recharge or replace equipment, underwater power nodes could remain in place for long periods and provide electricity to sensors and autonomous underwater vehicles.

That could mean longer missions for drone submarines without relying on traditional power cables or regular resupply trips.

Retired Admiral John M. Richardson, a former Chief of Naval Operations and member of Zeno's Advisory Board, said, "ubiquitous access to power in maritime environments is critical to maintaining US leadership."

Why strontium-90 is being revived

Strontium-90 has already been used by the US government in radioisotope power systems. During the 1960s through the 1980s, similar technology powered maritime equipment such as navigational buoys and underwater sensors. The older systems were reliable but relatively heavy.

Zeno is attempting to modernize the concept by combining a redesigned strontium-90 heat source with Stirling power conversion technology. The idea is to turn the steady heat generated by radioactive decay into electricity for locations where conventional energy sources are difficult to use.

The same technology could power lunar missions

The seabed isn't the only place where Zeno sees an opportunity. In July 2023, the company received a $15 million NASA Tipping Point award to develop a similar radioisotope power system with Blue Origin and Sunpower for potential lunar applications.

That means the same basic technology could eventually serve two very different environments: the deep ocean and the Moon.

Both present the same fundamental challenge — supplying reliable power where solar energy, cables and frequent maintenance aren't always practical.

Old radioactive material gets a surprising second life

The Oak Ridge transfer could therefore become more than an environmental cleanup story. For the government, it offers a way to remove aging radioactive material from a facility while reducing disposal costs.

For Zeno Power, it provides a domestic source of strontium-90 that could help support development of long-duration power systems for defence and space missions.

The Pentagon's DEPTHS demonstration will ultimately determine whether the concept can move beyond development and into practical deployment.

If it succeeds, material once viewed primarily as a disposal problem could become part of a new generation of long-lasting nuclear power systems operating beneath the ocean — and potentially on the Moon.