The buildings coming out of service at Y-12 were poured during the Manhattan Project. The ones replacing them cover more than 460,000 square feet across seven subprojects, and four of those subprojects are already done.
Bechtel National is the engineering, procurement and construction contractor, working under Consolidated Nuclear Security, the Bechtel-led management and operating contractor for Y-12 and Pantex. The NNSA cost baseline is $6.5 billion.
Project Scope
The Uranium Processing Facility is a multi-building complex, not a single structure. Site Readiness, Site Infrastructure and Services, the Substation and the Mechanical Electrical Building are complete. The Main Process Building, the Salvage and Accountability Building and the Process Support Facilities are in the final stretch.
The milestone that moved the job into its last phase came in June 2025, when the Salvage and Accountability Building — the last building tied into the Y-12 grid — was energized. That put the project into systems testing and commissioning. In July 2026 the related Calciner Project received authorization, which sets up the decontamination and shutdown of legacy Building 9212.
Peak site workforce ran past 3,000. Bechtel reports 480-plus suppliers across 42 states and 560 unique vendors on the procurement side.
Why It Matters
UPF is the largest NNSA construction project since the Cold War, and it’s a useful case study in what a decade-plus federal nuclear build actually looks like on the ground. The GAO has tracked it since 2020; the original $6.5 billion baseline and 2025 completion date are both public, and the project is visibly past the latter. NNSA hasn’t published a revised completion date.
For contractors, the interesting part isn’t the schedule, it’s the sequencing. Y-12 is an operating security complex, so every subproject had to be built, energized and commissioned without interrupting the mission running next door. Site infrastructure and the substation came first for exactly that reason. It’s the same logic that governs hospital and airport phasing, at nuclear security clearance and with a supply chain spanning 42 states.
Project Team & Details
| Developer | Consolidated Nuclear Security, LLC |
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| Owner / Client | U.S. Department of Energy / National Nuclear Security Administration |
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| Architect | Bechtel National, Inc. |
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| General Contractor | Bechtel National, Inc. |
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| Major Subcontractors | Hartman Walsh (Industrial Coatings) |
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| Status | Under Construction |
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| Delivery Method | Design-Build |
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| Funding Source | Public (Federal) |
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