A new facility for manufacturing nuclear-weapon secondary stages will not be completed until August 2026: eight months later than expected, the head of the National Nuclear Security Administration (NNSA) told Senators Wednesday in a hearing.

Bechtel National, under contract to the Bechtel-led site prime Consolidated Nuclear Security, has been building the current incarnation of the Uranium Processing Facility at the Y-12 National Security Complex in Oak Ridge, Tenn., since 2018, following years of design revisions to fit the next-generation plant into a budget that would pass muster with Congress.

UPF was supposed to be finished in December 2025 and cost no more than $6.5 billion, under a 2012 plan developed by the Department of Energy to appease Sens. Lamar Alexander (R-Tenn.) and Sen. Dianne Feinstein (D-Calif.), then the chair and ranking members of the Senate Appropriations energy and water development subcommittee. 

But “now, I understand the new delivery date has been pushed out to August of 2026,” Sen. Bill Hagerty (R-Tenn.) said during a subcommittee hearing on the agency’s budget request. “Is that correct?”

“That is correct,” said Jill Hruby, administrator of the Department of Energy’s NNSA and the lead witness in Wednesday’s hearing. “We have a review going on right now to look at what the cost implications will be for the extension and we should have those numbers later this summer.”

Hruby offered no numbers but said the NNSA anticipates “a relatively minor cost increase” for the next-generation uranium complex: three buildings to replace many of the functions of the aging Building 9212.

UPF is “a very large, long-term construction project,” Hruby testified Wednesday. “That’s very difficult to do and we were doing that during COVID. The heart of that construction occurred during COVID. So I just want to say that I think, given the one-of-a-kind construction, for a large, $6.5 billion facility that occurred over eight years, that an eight-month construction delay and what we anticipate to be a relatively minor cost increase is a commendable accomplishment.

“Obviously we’d like to be exactly on time but given the conditions that we were working in, I still think this is a tremendous success for the country,” Hruby said.