NUCLEAR DEPTHS: Pentagon Developing Seafloor 'Charging Stations' To Power Unmanned Submarines for Years

The U.S. Military is developing underwater nuclear-powered charging stations designed to sustain autonomous submarines, sensors and other military systems on the ocean floor for extended periods without surfacing. The DEPTHS initiative, backed by substantial initial funding, addresses a key challenge in undersea operations: maintaining power for unmanned systems during long-duration missions in deep water.

The Pentagon is exploring compact nuclear batteries that could operate continuously on the seabed for decades, using strontium-90, a radioactive material produced as nuclear waste and held in government facilities. As the material decays, it generates heat that new power-conversion technology can transform into electricity more efficiently than earlier systems, enabling smaller yet more powerful energy sources.

Current autonomous underwater vehicles and sensors face constraints from limited battery life, forcing the military to either recover systems or dispatch ships and crews for maintenance - an expensive and logistically demanding process. The Pentagon aims to establish underwater docking stations where unmanned submarines and robotic systems could autonomously dock, recharge and resume operations without surfacing.

The effort reflects broader U.S. Strategic focus on competition with China in the Pacific, where both nations are investing in undersea surveillance, autonomous systems and technologies to monitor extensive maritime areas. China has reportedly expanded sophisticated surveillance infrastructure along Pacific seabed sections, underscoring the strategic importance of long-endurance American underwater capabilities.

Zeno Power, developing the nuclear technology, has leased a secure California nuclear facility for system assembly. The company aims to show a working model and deliver the first underwater charging stations to the military by 2027.

While radioactive power systems exist, traditional designs have been large and heavy with modest power output. Recent advances in power conversion and engine efficiency could enable far more compact systems generating substantially greater power. Unlike solar, wind or conventional fuel systems, nuclear batteries require no sunlight, fuel deliveries or surface infrastructure, making them suited for deep ocean conditions.

If successful, the DEPTHS program could significantly extend the endurance of America's unmanned underwater fleet, allowing submarines, robots and sensors to operate undetected for years at a time.