ALEXANDRIA, Va. — The National Nuclear Security Administration delayed a choice about whether to use government or commercially developed uranium enrichment technology for defense needs by nearly a year because the government alternative is not yet mature enough to compete, an agency official said here Wednesday.

“That’s one of the reasons, not the only, but one of the reasons,” Michael Thompson, the agency’s assistant deputy administrator for major modernization programs said in a question and answer session here at the ExchangeMonitor’s

annual Nuclear Deterrence Summit.

Late last year, the National Nuclear Security Administration (NNSA) told Congress it was delaying a decision on whether to use the Oak Ridge enrichment technology or Bethesda, Md.-based Centrus Corp.’s [LEU] AC100 technology as the basis for the next U.S., defense-usable uranium refineries. The agency had for years planned to choose between the two in December 2019.

“AC100 technology is mature enough, we think, to compete,” Thompson said here. “[T]he small centrifuge being pursued by Oak Ridge National Lab is in the process of maturing and we want to make sure that that is at an appropriate point so that we can have, essentially, two choices.”

Thompson said there are even “some other potential outside vendors … that may compete down the road, but I would say those are probably less mature and more aspirational at this stage.”

Thompson did not identify these vendors by name. He said the NNSA planned to wrap up its analysis of alternatives between Oak Ridge and Centrus “at the end of this year,” then “start the acquisition process formally to deploy an enrichment technology in the 20s.”

Centrus, the former U.S. Enrichment Corp. that emerged from bankruptcy reorganization in 2014, has been busy buffing up for the competition with Oak Ridge.

In 2019, DOE’s Nuclear Energy Oak Ridge Site Office gave Centrus a three-year 80/20 cost-share contract — worth about $115 million, including a two-year base and a one-year option — to build a 16-machine cascade of AC100-M centrifuges at DOE’s Portsmouth Site near Piketon, Ohio.

The machines will be constructed only from U.S. parts, making them potentially usable for defense programs — something that Centrus’ now-decommissioned American Centrifuge Project, built in the same Portsmouth building that will house the new cascade, could not. The old project included some parts that carried international peaceful use restrictions.

The DOE science office wants the 16-machine Centrus cascade to produce, by October 2020, a test batch of high-assay, low-enriched uranium fuel containing about 20 percent U-235. The fuel could be used to help DOE develop a fleet of next generation nuclear reactors, the agency has said.

 AC-100 is also known as the “large centrifuge” technology that is competing with the Oak Ridge-developed “small centrifuge,” in the ongoing NNSA evaluation.

Whatever domestic enrichment technology the NNSA chooses would initially be used to produce low-enriched uranium that could help produce tritium — that radioactive hydrogen isotope that increases the yield of nuclear weapons. The NNSA irradiates tritium producing burnable absorber rods in Tennessee Valley Authority’s Watts Bar Unit 1 Reactor. Watts Bar Unit 2 was cleared last year by the Nuclear Regulatory Commission to start irradiating tritium rods in 2021, Thompson said here. 

Eventually, the NNSA will need high-enriched and weapons grade uranium for nuclear naval fuel and future nuclear-weapon refurbishments.

In the meantime, the agency’s stockpile is holding up, and BWX Technologies [BWXT] subsidiary Nuclear Fuel Services, of Erwin, Tenn., will downblend high-enriched uranium “not usable for other program reasons” into low-enrich uranium that can be used for tritium production.

That will keep NNSA in tritium until 2041, Thompson said. Nuclear Fuel Service’s downblending contract is worth more than $500 million and calls for the company to downblend more than 20 metric tons of the NNSA’s stock of highly enriched uranium. Without the downblending, NNSA would out of low-enriched uranium for the tritium program later this decade, the agency has said.