A Y-12 National Security Complex employee practices calciner procedures with surrogate material. Image by Consolidated Nuclear Security, LLC

OAK RIDGE, TN  –  The Y-12 National Security Complex received startup authorization on July 2, 2026, for the site’s Calciner Project.  The National Nuclear Security Administration and Consolidated Nuclear Security, LLC achieved this milestone that helps enable ongoing work to transform and recapitalize the site to support its nuclear deterrent mission.

A Y-12 National Security Complex employee operates equipment as part of the readiness review for the calciner process. Image by Consolidated Nuclear Security, LLC

The calciner system will support the decontamination and shutdown of a WWII-era production building by processing uranium-bearing solutions from pipes and other vessels into a stable, solid form for safe and efficient storage. This process replaces a wet chemistry process that was less efficient and more hazardous.

“Calciner is a key part of the long-term strategy to transition operations out of a more-than-80-year-old building and into the new Uranium Processing Facility (UPF),” said National Nuclear Security Administration (NNSA) Administrator Brandon Williams. “Achieving startup authorization for the calciner is an important step for the overall safety, security, and long-term viability of uranium operations for the nation.”

Y-12 employees demonstrate operational procedures as part of the readiness review for the calciner. Image by Consolidated Nuclear Security, LLC

Strategy for uranium operations

Bringing the calciner online supports Y-12’s operational strategy for uranium. Those strategic objectives are to:

• decrease safety risks by decreasing uranium inventories in process facilities;
• sustain existing operations by implementing improved technologies and relocating processes where feasible;
• extend the life of critical buildings; and
• move major uranium operations to the state-of-the-art UPF.

“Converting uranium solutions with the calciner is safer and more efficient,” said Todd Ailes, president and CEO of Consolidated Nuclear Security, which manages and operates Y-12 for NNSA. “Bringing this process online will reduce risk and consolidate storage.”

Calciner is the second authorized nuclear operations process startup at Y-12 within the past year, following electrorefining, which was the first startup of a new nuclear operation on site in approximately 20 years. Ultimately, the Calciner Project at Y-12 demonstrates a commitment to the nation and its allies that Y-12 is modernizing infrastructure, improving safety, and increasing operational efficiency to deliver the nation’s nuclear deterrent.

Consolidated Nuclear Security, LLC, operates the Y-12 National Security Complex, located in Oak Ridge, Tennessee, for the U.S. National Nuclear Security Administration. Bechtel National, Inc., is the lead member of CNS; minority members include Leidos, Inc.; ATK Launch Systems, LLC; and SOC, LLC. Y-12 is a key facility in the U.S. Nuclear Security Enterprise, and CNS performs its work with a foc

For more information on Y-12, visit www.y12.doe.gov. Follow Y-12 on Facebook, X, and LinkedIn.