ALEXANDRIA, Va. — The National Nuclear Security Administration (NNSA) has delayed its choice about whether to use government or commercially developed uranium enrichment technology for defense needs by nearly a year, in part, because the federal option 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, NNSA assistant deputy administrator for major modernization programs, said in a question-and-answer session at the ExchangeMonitor’s annual Nuclear Deterrence Summit.
Late last year, the semiautonomous Energy Department branch told Congress it was delaying a decision on whether to use the Oak Ridge enrichment technology or Bethesda, Md.-based Centrus Corp.’s AC100 centrifuge 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.
Centrus’ “AC100 technology is mature enough, we think, to compete,” Thompson said. “[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 “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 plans 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 international parts that, according to the Department of Energy, could only be used for peaceful purposes, under international agreements.
AC100 is also known as the “large centrifuge” technology that is competing with the Oak Ridge-developed “small centrifuge,” in the ongoing NNSA evaluation.
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% uranium-235. The fuel could be used to help DOE develop a fleet of next-generation nuclear reactors, the agency has said.
Whatever domestic enrichment technology the NNSA chooses would initially be used to produce low-enriched uranium that could be used in generating tritium — that radioactive hydrogen isotope that increases the yield of nuclear weapons. Eventually, the NNSA will also need high-enriched and weapon-grade uranium for nuclear naval fuel and future nuclear-weapon refurbishments.
The NNSA irradiates tritium-producing burnable absorber rods in Tennessee Valley Authority’s Watts Bar Unit 1 reactor. Watts Bar Unit 2 was cleared to start producing tritium in 2021, Thompson said here.
For now, the agency’s stockpile of uranium suitable for tritium production is holding up. BWX Technologies subsidiary Nuclear Fuel Services, of Erwin, Tenn., will downblend high-enriched uranium that Thompson said is “not usable for other program reasons” into low-enrich uranium that can be used for tritium production.
That will keep the 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 have run out of low-enriched uranium for the tritium program later this decade.
