Elizabeth Warren, USCA Overflow, Speech

U.S. Sen. Elizabeth Warren, a Massachusetts Democrat running for president, speaks to an overflow crowd at her USC Aiken town hall in August.

Two Democratic presidential candidates believe there is no reason to produce 80 plutonium pits per year, as is planned, and have urged congressional defense leaders to step back and reconsider related legislation, according to a missive reviewed recently by the Aiken Standard.

In a Sept. 13 letter, U.S. Sens. Bernie Sanders of Vermont and Elizabeth Warren and Ed Markey of Massachusetts described a significantly bolstered pit production mission as "unnecessary, unachievable and ill-advised," citing an independent analysis that earlier this year cast serious skepticism on the National Nuclear Security Administration's and U.S. Department of Defense's recommended path forward.

That report, handled by the Institute for Defense Analyses, listed three cautionary findings in its publicly available summary: Reaching 80 pits per year is possible, but "extremely challenging"; no available option will likely satisfy the demand by deadline; and further risk assessment is needed.

A Congressional Budget Office study released earlier this year very roughly estimated pit production to cost $9 billion over the next decade.

At least 80 pits per year are needed by 2030, according to the 2018 Nuclear Posture Review, a leading Pentagon nuclear policy document. The pits – nuclear weapon cores, often referred to as triggers – will be used to refresh the nation's nuclear stockpile, officials have said.

To meet that requirement, the NNSA and the Defense Department last year recommended producing 50 pits per year at the Savannah River Site, south of Aiken and northwest of Charleston, and the remaining 30 per year at Los Alamos National Laboratory in northern New Mexico. National Nuclear Security Administration chief Lisa Gordon-Hagerty in June told the Aiken Standard meeting the mark will be a challenge, but a worthy one.

"That is our plan. That is our goal. That is our effort," she said, adding: "It's a high bar, I have to say that. It is absolutely a high bar. But I believe that our entire infrastructure, the investments that we're making, and the commitment of our enterprise, we can do it."

The trio of senators, however, contend 80 pits per year is unnecessary – "not required for U.S. security," they together wrote. That mirrors concerns raised by nuclear watchers and independent monitoring groups alike.

Stephen Young, a Washington representative for the global security program at the Union of Concerned Scientists, on Friday said he agreed with the stance taken in the letter.

"Basically, the science shows that pits last roughly 100 years, and we already have thousands of pits in storage, and the weapons we have in the stockpile now are in good shape," Young said.

Sanders, Warren and Markey in their letter encouraged leaders of the two armed services committees to support legislative language dialing back the pit count as well as slashing money for it.

"We call on you to support the House language, which sensibly reduces the 80-pit requirement to 30 pits per year by 2026," reads the letter, which is a little more than two pages long. "It also cuts funding for pit production by $241 million, to $471 million."

Warren was the first presidential candidate to campaign in Aiken this election cycle. She did not mention pit production during her town hall at USC Aiken, about 20 miles north of the Savannah River Site. 

Sanders campaigned in nearby Augusta in May.

The NNSA, established in 2000, is the U.S. Department of Energy's semiautonomous weapons and nuclear nonproliferation wing.

Colin Demarest covers the Savannah River Site, the U.S. Department of Energy, the National Nuclear Security Administration and government in general. Follow him on Twitter: @demarest_colin