US nuclear start-up Zeno Power is establishing a nuclear battery manufacturing facility at the Vallecitos Nuclear Center in Sunol, California. Zeno is leasing legacy specialised hot cell infrastructure from decommissioning specialist NorthStar Group Services.
Zeno’s batteries do not rely on nuclear fission, chain reactions, or uranium. Instead, they trap the natural decay heat generated by radioactive isotopes and convert it directly into electricity using highly efficient Stirling engines or thermoelectric materials.
While NASA has used similar technology since the 1960s (using rare and costly Plutonium-238), Zeno uses alternative, more abundant nuclear waste isotopes. These include strontium-90 repurposed from legacy nuclear material to power seabed operations, maritime sensors, and deep-ocean autonomous vehicles; and americium-241 sourced through a strategic recycling agreement with French nuclear operator Orano to fuel space and lunar missions.
Zeno has secured over $60m in anchor contracts with the US Department of Defense (DOD, now Department of War) and NASA. For NASA’s Project Harmonia Zeno is leading a consortium, including Blue Origin and Intuitive Machines, to develop a radioisotope power system that allows lunar landers to survive and operate through the freezing, two-week-long lunar night.
For the US Space Force, Zeno is designing a lightweight nuclear battery optimised to supply continuous electricity to electric thrusters. This allows military satellites to constantly change orbits and dodge threats without running out of fuel or relying on bulky solar panels
For the US Navy/Pentagon, Zeno is building rugged, pressure-proof power capsules that can be dropped onto the ocean floor to run underwater surveillance grids completely unattended for decades.
After achieving a successful prototype demonstration, Zeno is on track to build full-scale systems, with commercial deliveries slated for 2027 from its new Vallecitos production facility.
This lease agreement with NorthStar enables Zeno to fulfil initial deliveries to government customers in 2027 and then quickly scale production. With strong follow-on demand from government and commercial partners, Zeno is positioned to deliver nuclear batteries at scale beginning in 2028.
The 1,600‑acre Vallecitos Nuclear Centre is a nuclear research facility and site of the privately-owned Vallecitos boiling water reactor (VBWR), which operated from 1957 until 1963. The plant was originally a collaboration between General Electric and Pacific Gas & Electric Company, with Bechtel Corporation serving as engineering contractor. As well as the VBWR, the site hosted a Radioactive Materials Laboratory where post-irradiation examinations were carried out as well as a small 100kW Nuclear Test Reactor.
Waste removal from the Vallecitos centre took place in 2009 and 2010 and the VBWR was removed by Northstar in 2023. In March 2025, NorthStar Group Services finalised an agreement to accept ownership of the Vallecitos Nuclear Center from GE Vernova and GE-Hitachi Nuclear Energy Americas (GEH) for nuclear decontamination, decommissioning, and environmental site restoration. NorthStar’s decommissioning work will continue across the broader site in parallel with Zeno’s manufacturing activities in the discrete hot cell portion of the complex.
“As NorthStar continues to decommission Vallecitos, we made the decision to preserve the hot cell facility, knowing it had future value for our mission,” said Scott State, CEO of NorthStar. “We’re proud to partner with Zeno to utilise the facility for beneficial use – building nuclear batteries to power the frontier.”
Zeno plans to add more than 50 jobs in the Tri-Valley area over the next three years, drawing on the engineering, nuclear, and operations talent across Berkeley, Livermore, and Silicon Valley. This will be the company’s third location, with existing office and lab facilities in Seattle, and Washington, DC.
“This is a major win for Alameda County,” said David Haubert, Alameda County Supervisor. “Zeno’s investment creates high-skilled jobs, preserves decades of irreplaceable nuclear expertise at Vallecitos, and generates significant economic activity in our region. We’re proud that Alameda County will be home to the advanced manufacturing capabilities that power America’s defense, space exploration, and commercial missions.”
