Federal officials estimate Los Alamos National Laboratory won’t produce 30 nuclear bomb cores until 2030 — four years after the legally required deadline.

The additional time needed to produce 30 bowling-ball-sized warhead triggers, known as pits, will cost the lab significantly more than originally estimated, a government watchdog said in a newly released report.

The agency in charge of the country’s nuclear arsenal estimates in the Government Accountability Office report it will take until 2030 for the Los Alamos lab’s plutonium facility to be capable of making 30 pits.

An additional two years will be needed for the lab to reliably produce that number of pits every year.

This timeline is four years later than the statutory requirement, the report notes, referring to a law Congress passed in 2018 requiring 30 pits to be manufactured per year by 2026.

Although some high-ranking officials have expressed doubts for years about whether the lab could meet what they called an overly optimistic target date, those involved in the pursuit have been reluctant to admit it couldn’t be done because they didn’t want to contradict the law.

Congress enacted the law in response to the Trump administration’s plan for nuclear readiness — and the task fell to the lab because it’s the only entity in the country that can make plutonium pits.

In recent months, officials at the National Nuclear Security Administration, which oversees the lab, have begun to publicly acknowledge more time is needed to fully ramp up pit production, while not entirely discounting the 2026 target.

“The challenge for them is they’re sort of backed into a corner because they haven’t had the relief from the statutory requirement, even though there’s broad acknowledgment that it’s not realistic,” Allison Bawden, the GAO’s director of natural resources and environment, said in an interview.

Nuclear security managers and others can telegraph 2026 is unrealistic, but at the same time they’ll be cautious about saying they can’t comply with the law, Bawden said.

Some congressional leaders have criticized the deadline.

U.S. Rep. John Garamendi, D-Calif., earlier this year tried to get the law repealed, but his effort was rejected.

A spokeswoman for the nuclear security agency did not respond directly when asked about the later production timeline outlined in the report but emailed a link to a June newsletter that states “equipment installation will not happen quickly enough to support 30 WR [war reserve] pits per year by 2026.”

War reserve pits are certified to be used in nuclear weapons. Military leaders, nuclear security officials and some political leaders say new pits are needed to modernize the arsenal to deter Russia, China and rogue countries from acting rashly with their nuclear weapons.

Bawden said the agency wants the lab to install backup equipment to create reliable 30-per-year pit production — essentially to ensure if one piece of machinery fails, the entire operation won’t shut down. Agency heads expect the backup hardware to be installed by 2032, she said.

Taking years longer to meet the pit production target will substantially increase the lab’s overall costs, Bawden said, adding it’s not clear by exactly how much.

This year, the lab received $1.6 billion for plutonium modernization and operations. The nuclear agency had planned to taper funding after 2026, when pit production was previously expected to be in full gear.

Bawden said the agency spending more on pit production than originally envisioned isn’t technically a cost overrun because no funding baseline was ever established.

This means there’s no benchmark anyone can point to and say the agency has spent too much, she said, which in turn leaves funding for pits open-ended.

“It’s definitely cost growth,” she said.

Lab Director Thom Mason, who has repeatedly expressed confidence in making the 2026 pit production deadline, said in an interview Friday the lab is now shooting for 2028 due to challenges in installing equipment.

The lab remains on track to produce the first war reserve pit in 2024, Mason said, but reaching the full production target will take more time because of logistics.

At the plutonium facility, crews installing equipment have conflicted with those doing daily production work in a fairly cramped space, slowing upgrades, Mason said. The encumbered installation led to nuclear officials estimating it would take until 2030 to produce 30 pits, he said.

Before, installation was done in the two later shifts, and production was done during the day, Mason said.

Crews on all three shifts now will be involved in installing equipment, he said.

Mason said crews recently made 14 prototypical pits in a year, double the lab’s goal of seven, giving him confidence the facility can make 30 pits by 2028 after all the new machinery is in place.

As far as the congressional mandate of 2026, Mason said it’s useful to have that as a target for focus and discipline.

“That helps drive the planning; it helps drive the funding that’s necessary, and the decision-making,” Mason said. But he added: “At the end of the day, reality dictates when the pits get made.”

A longtime nuclear activist said the federal government has been underestimating the time and money needed for this massive project for years.

It’s yet another sign that forcing the lab to become a pit factory is not feasible and mainly serves to draw huge amounts of federal funding, said Greg Mello, executive director of Los Alamos Study Group.

Keeping an unachievable deadline also is a funding ploy, Mello charged.

“They don’t want to lose that sense of urgency,” he said. “Gee, we’re probably not going to make this target, but the more money you give us, the more likely … we might hit it.”

Bawden said some leaders have opposed eliminating the 2026 deadline because they think it will send the wrong message that it’s OK to go slower.

“I don’t know if living in an unrealistic universe helps with speed,” Bawden said. “Does having the statutory requirement keep the pressure on? Sure. But it’s not going to help them meet it, either.”