Potential NNSA boss backs dilute-and-dispose plutonium plan involving SC, New Mexico

• By Colin Demarest cdemarest@aikenstandard.com
• June 10, 2021

President Joe Biden’s pick to lead the National Nuclear Security Administration recently endorsed plans to process metric tons of plutonium and entomb the final product in New Mexico, a means of disposal that South Carolina officials have criticized.

Nominee Jill Hruby in testimony published last month described what’s known as dilute-and-dispose as “a safe, secure and environmentally responsible approach” to ridding of excess plutonium, a hazardous nuclear-weapons ingredient.

The method, she said, uses “existing, proven technologies, and will allow the United States to meet its disposition commitments in less time and at half the cost of the” Mixed Oxide Fuel Fabrication Facility, which was canceled in late 2018 after billions of dollars and years of work had been invested at the Savannah River Site footprint.

Dilute-and-dispose is also known as downblending, and is considered the way forward after the MOX fiasco. The time-consuming process involves converting the plutonium into an oxide, adulterating it and, ultimately, shipping the mixture to southeastern New Mexico for burial at the Waste Isolation Pilot Plant, a Department of Energy repository resembling a salt mine.

The multi-state and -site endeavor has been estimated to cost roughly $18.2 billion – markedly less than MOX, according to Hruby and Trump-era officials. It will take decades to complete, leaving it vulnerable to swings in workforce, resources and public opinion and education. 

In a preface to a recent National Academies study, Robert Dynes, the chairman of the Committee on Disposal of Surplus Plutonium at the Waste Isolation Pilot Plant, said the dilute-and-dispose “plan is not technically complex.” But, he continued, the “true challenges lay in the many mostly nontechnical threads that are connected to the technical plan.”

“It is important to stress that the program was and is evolving in real time,” he added. 

Gov. Henry McMaster and Sen. Lindsey Graham, two South Carolina Republicans, have attacked the dilute-and-dispose approach, describing it as immature, conceptual, half-baked. Canceling MOX, Graham has said, was a “colossal mistake.”

Hruby last month pledged to work with New Mexico and other officials to help educate the public on the dilute-and-dispose process.

Hruby will need to be confirmed by the full Senate.