The roughly 1% annual increase the Joe Biden administration proposed for civilian nuclear weapons programs is “minimally sufficient” to keep warhead and bomb modernization on track in 2022, but maybe not beyond, a joint Pentagon-Department of Energy nuclear acquisitions group told Congress in a letter dated Friday.

The Biden request of roughly $20 billion for the Department of Energy’s National Nuclear Security Administration (NNSA) in fiscal year 2022 “meets immediate, known nuclear weapons stockpile and Stockpile Stewardship Program requirements for [fiscal year] 2022 only,” the Nuclear Weapons Council certified to Congress in the letter delivered to the Armed Services and Appropriations Committees of both chambers.

The council warned that anything less than the request in fiscal year 2022 “would result in program delays and misalignment with complementary DoD nuclear modernization programs, and therefore, potentially significant cost increases to DoD sustainment and acquisition programs.”

At deadline on Tuesday, the full House of Representatives was set to vote on a seven-bill appropriations package that would provide roughly the requested funding for NNSA nuclear weapons programs.

We agree with the [Nuclear Weapons Council] that the Biden budget request ‘injects risk’ in the cornerstone of our national security, and we further agree with the [council’s] ‘unanimous and grave concern that accepting increased programmatic risk within NNSA’s nuclear weapons activities will further increase operational risk.’” Sen. James Inhofe (R-Okla.) and Rep. Mike Rogers (R-Ala.), ranking Republicans on the Senate and House Armed Services Committee, wrote in a statement Tuesday.

“As the letter states, the Nuclear Weapons Council unanimously supported the President’s FY22 Budget Request for NNSA Weapons Activities,” an aide for the Democrat-controlled House Armed Services Committee said. “This is the largest request for Weapons Activities in NNSA history. Those are the facts. It is by no means surprising to read in a Department of Defense document that they could use additional resources to reduce risk.”

Among the most controversial of NNSA’s nuclear weapons programs, especially with more left-leaning members of Congress’ thin Democratic majority, is the NNSA’s plan to build a pair of plutonium pit factories at the Los Alamos National Laboratory in New Mexico and the Savannah River Site in Aiken, S.C. Pits are the fissile cores of nuclear weapons.

By law, the Nuclear Weapons Council must certify annually that, among other things, the NNSA’s budget request is adequate to meet a statutory requirement to be able to produce at least 10 war-usable plutonium pits by fiscal year 2024, at least 20 pits by 2025, at least 30 pits by 2026 and at least 80 pits by 2030.

These challenging construction projects have already faced delays. The NNSA told Congress earlier this year that the Savannah River plant will not be ready to come online by 2030 as required. 

Moreover, the NNSA might need more than two percent annual growth in its budget to keep up with future upgrades to its “long-term infrastructure capacity,” the Nuclear Weapons Council warned in the letter.

The NNSA owns, maintains and modernizes U.S. nuclear warheads and bombs.