Sandia National Laboratories crews topped out the steel structure of a 136,000-square-foot Power Sources Capability building on April 14, 2026, marking one of the labs' largest construction projects of the past decade and a key investment in the nation's nuclear weapons stockpile stewardship program.

The $400 million facility in Technical Area II will consolidate work that currently spreads across four separate buildings, most of which lack the modern infrastructure the mission requires. Construction began in August 2025; topping out concludes the steel phase, with full building completion targeted for 2028 and equipment transition afterward.

"Construction is advancing ahead of schedule," project manager Savannah Torres said. "We've met or exceeded all major milestones to date and intend to keep up the pace."

Why a new building now?

The new structure replaces aging facilities without the capacity to run all power sources work under one roof. Sandia's responsibilities cover research and development, design, production, and surveillance of power sources for nuclear weapon systems, where energy storage components must function from separation through detonation.

"Every system needs a power source," said Sara Pecak, a senior manager. "Our program spans four technology areas, including thermal batteries."

The current setup forces staff to shuttle between buildings for tasks that include work in dehumidified "dry rooms" essential to power source manufacturing. "One of the things we asked for in the new building is the ability for people to walk past one another," Pecak said. "That's part of the design concept. We want to create an environment where people can have conversations even if they're not working on the same projects."

How was the design shaped to last 50 years?

Conceptual design work began in 2019 and went through extensive value engineering before construction. The redesign preserved mission function while reducing cost, improving constructability, and adding flexibility for changing missions.

"We've created what we think is one of the most efficient design concepts to meet the mission both today and for the next 50 years," said Perry D'Antonio, a senior manager overseeing the project's technical requirements. "We want to build in agility for changing missions over the building's lifespan."

D'Antonio added: "We want to celebrate all the work that's been done to date and reaffirm our commitment to delivering on the remaining work."

What capabilities does the mission actually require?

The lab describes the manufacturing environment as uniquely constrained. "Making power sources requires some unique capabilities, such as dehumidified rooms, also called dry rooms," Pecak said. "The stringent requirements and limited supplier base require the nation to maintain this capability internally."

Sandia's Energy and Critical Infrastructure portfolio designs and produces thermal batteries and related components that must survive decades of dormant storage before delivering main mission power. The single facility is meant to give program managers one controlled environment instead of a fragmented footprint.

Who is paying, and who is building?

The $400 million sits within Sandia's multi-billion-dollar line-item construction portfolio, overseen by the National Nuclear Security Administration. Hensel Phelps serves as general contractor; SmithGroup is the architecture and engineering firm.

Torres credited the cross-functional team for keeping schedule. "The expertise of the architecture and engineering firm and the general contractor, combined with support from the cross-functional Sandia and NNSA team, has been instrumental in positioning the project for successful execution," she said. "This project not only delivers the facility needed to advance the power sources mission but also establishes a strong framework for future projects within Sandia's multibillion-dollar line-item portfolio."

The Power Sources Capability building sits south of the Battery Test Facility on the Albuquerque campus. With structural steel complete, site work now shifts to enclosure, interior buildout, and the specialized process systems thermal-battery manufacturing will require through the 2028 handover.