As a further sign Los Alamos National Laboratory is inching toward its 2026 target for making 30 warhead triggers a year, nuclear security managers plan to construct five buildings in the lab’s plutonium complex over the next five years, in part to support that effort.

A new building would be funded annually, beginning in fiscal year 2023, with the aim of supporting production of the bomb cores, known as pits, and other plutonium operations, according to the National Nuclear Security Administration’s budget request for the coming year.

The total cost of the five buildings will be more than $240 million.

It’s the first time new building construction has been outlined in the budget for the lab’s plutonium facility, an aging, late-1970s complex the agency wants to overhaul so it can help upgrade the country’s nuclear arsenal.

The buildings will house personnel who mainly would carry out administrative tasks related to pit production, plutonium science and nuclear waste disposal, an agency spokesman said.

Because of the broader purpose, the agency will pay for the construction out of its general infrastructure funds rather than with money budgeted for pit production, spokesman Gordon Trowbridge said, adding some existing buildings will be renovated as well.

He emphasized pit production isn’t the sole driver of the expansion.

“Both new construction and improvement of existing facilities will support all plutonium operations, not just pit production,” Trowbridge said.

One critic of the lab’s pit production plans said each of the buildings was priced just under the $50 million threshold that would trigger a more rigorous congressional review.

That might allow the lab to change the office buildings into something else later for a different purpose, such as producing more pits, said Greg Mello, executive director of the Los Alamos Study Group.

“No one ever talked about these costs before,” Mello said. “We don’t think this is the end of the surprises. There are more surprises to come.”

The federal budget for plutonium operations has climbed steeply in recent years, both at the lab and at Savannah River Site in South Carolina, where officials hope to make an additional 50 pits yearly by the mid-2030s.

Under the U.S. Department of Energy’s draft budget, the lab’s plutonium modernization funding would climb to $1.56 billion in 2023 from the current year’s $1 billion, more than a 50 percent increase.

At the same time, the nuclear security agency, an Energy Department branch, has proposed funneling $700 million this coming year toward converting Savannah River Site into a pit factory. That’s a sizable jump from the $475 million spent for that purpose in the last budget cycle.

Aside from that, the agency’s heads have asked for additional money to buy hard-to-get items such as nuclear-safe pipes and glove boxes — the sealed containers in which workers handle radioactive materials — so they’re available when Savannah River’s pit plant comes online.

“It’ll increase the chance when we have the facility built, we can move that equipment in [and] we can begin production sooner,” Trowbridge said.

The agency’s administrator, Jill Hruby, has challenged the original timeline of 2030 for getting Savannah River to produce 50 pits, saying realistically it could take up to five years longer.

Hruby contends federal leaders should do everything possible to speed up the process, including buying equipment and materials ahead of time.

In a recent letter to the chairman of the House Armed Services Committee, Rep. Adam Smith, D-Wash., Hruby noted her agency received $500 million less than it requested to buy the necessary items in advance for Savannah River.

“The $500 million would allow activities to be started as early as possible for the Savannah River Plutonium Processing Facility,” Hruby wrote. “Recognizing the $500 million will not allow the NNSA to meet the requirement of 80 pits per year by 2030, the request supports meeting the requirement as close to 2030 as possible.”

One watchdog group questioned whether the agency getting less than it requested for Savannah River signaled a plan to shift pit production more toward Los Alamos.

Jay Coghlan, executive director of Nuclear Watch New Mexico, said federal officials want the lab’s pit plant to be able to produce up to 80 pits for short periods.

He contends the lab is likely to use this “surge capacity” given the longer time it will take for Savannah River to begin production.

Trowbridge said there is no real budget reduction. The agency is merely vying for a supplement to aid Savannah River’s eventual opening, he said.

“To portray that as a cut in the budget is inaccurate,” he said.

Trowbridge said Hruby has made it clear the agency has no immediate aim to increase the lab’s pit production beyond the original goal of 30 per year.

“That’s an ambitious goal,” Trowbridge said. “All of this work regarding pit production is challenging work.”