A team led by Fluor [FLR] won the potentially 10-year, $28-billion contract to manage the National Nuclear Security Administration’s (NNSA) two big nuclear-weapon production facilities in Tennessee and Texas.

The team beat out at least two other bids — one led by BWX Technologies [BWXT] and another led by Bechtel National — to become the long-term steward of the Pantex Plant in Amarillo, Texas, and the Y-12 National Security Site in Oak Ridge, Tenn. The former assembles and disassembles nuclear weapons, the latter makes nuclear-weapon secondary stages.

The NNSA, the semi-autonomous part of the Department of Energy that maintains and modernizes U.S. nuclear weapons and weapons production infrastructure, announced the award in a press release Monday.

Fluor has a 60% stake in the winning bidder, a company called Nuclear Production One LLC, which was registered in Delaware around the time the agency released the final solicitation for the next NNSA Production Office contract to manage Pantex and Y-12. The deal has five years of firm money and five one-year options.

The NNSA in 2020 decided to not to renew the contract of the Bechtel-led incumbent, Consolidated Nuclear Security, which will remain at Y-12 to continue building the Uranium Processing Facility: the next-generation factory for the components and elements of nuclear-weapon secondary stages.