The US Department of Energy’s (DOE) Office of Environmental Management (EM) has decided to restart HB-Line operations at the Savannah River Site (SRS) in South Carolina. The HB-Line will recycle surplus plutonium and partner with industry to produce uranium-plutonium mixed oxide (MOX) fuel for advanced nuclear reactors. The facility is an integral part of H-Canyon, the only chemical separations facility of its kind in the US.
The HB-Line is a specialised processing facility within the H-Canyon complex that has supported critical national nuclear missions. Following completion of its last mission in 2018, the facility was placed in a managed lay-up state, preserving its one-of-a-kind capability for future use.
The restart decision is the first step in a multi-year restart plan. Once operational, HB-Line will accelerate EM’s plutonium disposition mission by 10-13 years while reducing the existing cost and saving up to $350m. It will also create an opportunity to recover valuable isotopes currently available in limited quantities domestically, supporting critical needs in scientific research and commercial applications.
“Restarting HB-Line is the right decision for taxpayers, for our national security and for America’s energy future,” said EM Assistant Secretary Tim Walsh. “We are restoring a unique capability that will accelerate our mission, strengthen the domestic nuclear industrial base and deliver fuel the country needs to power advanced reactors.”
Savannah River Operations Office Manager Edwin Deshong noted: “Savannah River Site has been integral to America’s nuclear mission for more than 70 years, and HB-Line is one of the unique capabilities the site has to offer. Our workforce has the expertise, experience and dedication to execute the mission safely and successfully.”
The decision is in line with two of the four Executive Orders (EOs) signed by President Donald Trump in May 2025: EO 14302 – Reinvigorating the Nuclear Industrial Base and EO 14299 –Deploying Advanced Nuclear Reactor Technologies for National Security, which call for jumpstarting America’s nuclear industrial base.
H-Canyon is used to process nuclear materials by dissolving them in nitric acid to recover valuable isotopes or stabilise them for final disposal. The facility is named “Canyon” because its interior resembles a deep, narrow gorge between steep vertical walls. It is approximately 1,028 feet long, 122 feet wide, and 71 feet tall. Due to high radiation levels, most work is performed remotely using overhead bridge cranes from a control room. The “hot” side of the canyon has not been entered by humans since operations began in 1955.
H-Canyon was originally built to recover uranium and neptunium from fuel tubes to produce materials for nuclear weapons. Modern missions focus on environmental clean-up and nuclear non-proliferation. This includes:
- Down-blending: Converting weapons-usable highly enriched uranium (HEU) into low-enriched uranium (LEU) for use in commercial nuclear power reactors;
- Advanced Fuel Production: In February, the facility restarted uranium recovery to produce High-Assay Low-Enriched Uranium (HALEU) for next-generation advanced nuclear reactors.
- Used Nuclear Fuel Disposition: Dissolving used fuel stored at the site to accelerate its safe disposal and vitrification (turning it into glass for long-term storage).
It also serves as a technological Test Bed providing a real-world testing environment for outside parties to develop and validate new nuclear processing technologies.
