For science, keep it subcritical, NNSA defense programs head says

Marvin Adams, deputy administrator for defense programs at the National Nuclear Security Administration, told the Exchange Monitor Friday that the U.S. does not need to critically test, even in a new administration.

“If it’s based on purely technical considerations, we are confident that we can get the information we need staying subcritical,” Adams said. “We invested a lot in the design, the design of all these experiments. They’re all designed to stay subcritical. We know what we want out of them, and we’re confident we can get it.”

Adams spoke to reporters, alongside the National Nuclear Security Administration’s (NNSA) deputy administrator for defense nuclear nonproliferation Corey Hinderstein, at a press call ahead of a planned press tour of the Lawrence Livermore and Nevada National Security Site. 

“From a technical point of view, personally, and I can say I’m a subject matter expert on this, I personally don’t see that [testing] needs to go super critical,” Adams added. “But, you know, I can’t say what the next administration will decide policy-wise.”

The U.S. has not tested nuclear weapons at full yield since 1992 and has only conducted subcritical, zero-yield experiments in a self-imposed moratorium that roughly mirrors the provisions of the Comprehensive Test Ban Treaty, which the country has not ratified. 

Hinderstein reminded reporters on the call that NNSA, under a legal requirement established during the President Bill Clinton administration, must maintain the ability “to conduct an underground nuclear test using a test article drawn from the existing stockpile and using limited diagnostics within 36 months.” 

During now-President-elect Donald Trump’s campaign, some of his former advisors came out in support of a readiness to return to testing nuclear weapons at a critical level. Project 2025, a conservative policy document released over the summer and written by former Trump administration advisors, listed in its “needed reforms” that a “readiness to test nuclear weapons at the Nevada National Security Site [will] ensure the ability of the U.S. to respond quickly to asymmetric technology surprises.” 

Trump’s former national security advisor Robert O’brien also argued in an op-ed for Foreign Affairs magazine that the U.S. should ignore the 1992 treaty as long as China and Russia refused to engage in peace talks with the U.S.

“A second Trump term would see massive investments in this critical technology,” O’brien, whom Trump has not named as part of his upcoming administration and was not one of the Project 2025 authors, said in his article.

Jill Hruby, the head of the National Nuclear Security Administration, also said at a panel in Washington hosted by the Los Alamos Study group in November that the underground nuclear explosive test program was “expensive,” and that NNSA instead was using that money to execute the stockpile stewardship program.

“I think that… nearly everyone would tell you that we know more about the basic physics of nuclear weapons today than we’ve ever known before as a result of our science based stockpile stewardship program, not because of the test program,” Hruby said.