Amentum is the renamed former government services unit of AECOM, previously known as AECOM Energy and Construction, which was spun off and sold to private equity owners by the parent company in early 2020.

The joint venture will manage NNSA’s nuclear weapon stockpile stewardship program and support agency work in naval nuclear reactor development, defense nuclear security and nonproliferation and related areas.

The Pantex plant, which occupies 9,100 acres and contains 602 buildings totaling 3.5 million sq ft, has been the primary U.S. location for nuclear weapons assembly, disassembly and life-extension for more than 40 years.

Y-12 is an 800-acre complex at the Oak Ridge site with 370 buildings, some dating to World War II-era work on the Manhattan Project. It includes enriched uranium processing and storage, lithium and special material processing and related operations. NNSA said it designed the contract and transition period to minimize the impact on workers at Y-12 and Pantex.

The Fluor-led team includes subcontractors Criterion Systems, General Atomics and SOC, as well as several small businesses.

NNSA did not disclose the number of bids received for the contract or identities of the bidders.

Bechtel Replaced, But Is Still on Site

NNSA said in early 2020 it would not renew the Bechtel consortium for the last three years of its 10-year award, concluding that it fell short of its 80% at-risk fee needed to trigger the renewal.

The consortium failed to identify and address serious overtime and time keeping irregularities that caused overcharge and reduced productivity, NNSA said in its review. There were also performance issues, the agency said. Bechtel did not comment on its departure to ENR but last year told industry publication Weapons Complex Monitor that the "government’s decision is surprising and deeply disappointing."

However, Bechtel will remain at the Y-12 site to complete construction of the estimated $6.5-billion uranium processing complex that will replace by late 2025 a World War !!-era structure, a company spokesman told ENR. It has been part of the firm-led consortium's contract but will be split off in the site management transition.

Construction of its 242,000-sq-ft main processing building, which began in 2018, was completed in September. The structure is built to nuclear construction standards and will house casting, special oxide and some chemical recovery processes. It is one of seven building projects at the site under the uranium processing complex contract.

The Fluor-led team will be responsible for the procurement, processing, manufacture, fabrication, staging, storage and disposition of high-hazard enriched uranium, depleted uranium, special nuclear material, other special materials, high-explosives and nuclear weapon assembly/disassembly functions along with other work required by NNSA. The team also will manage partnerships to develop and deploy new technologies 

The contractor team will manage the site transition from legacy production facilities, NNSA said. It will design and build the lithium processing facility, the restart and modernization of depleted uranium operations, and initiation of new capabilities and processes. Other major initiatives include design, construction, and operation of the high explosive-testing and production facilities and other projects on site.

Amentum was on the team that won an estimated $8.3-billion contract in October for other work at the Y-12 industrial area, as well as the Oak Ridge National Laboratory and the East Tennessee Technology Park. Activities will include cleanup of excess facilities at the laboratory and Y-12 and the design, construction and operation of a new onsite disposal facility.