Efforts to commercialize production of high-assay, low-enriched uranium (HALEU) fuel, which is needed for an array of advanced reactors, ramped up this week with two major announcements.
As the Department of Energy (DOE) contracted Centrus Energy to demonstrate production of HALEU fuel for advanced reactors at the DOE’s American Centrifuge Plant in Piketon, Ohio, private fuel manufacturers Global Nuclear Fuel (GNF) and X-energy signed a collaboration to produce “low-cost” TRi-structural ISOtropic (TRISO) particle nuclear fuel, a type of HALEU fuel, at GNF’s licensed fuel fabrication facility in Wilmington, North Carolina.
The HALEU Centrifuge Project Is Underway
Bethesda, Maryland-headquartered Centrus, a company formerly known as the U.S. Enrichment Corp., said on Nov. 5 that the three-year contract allows it to deploy a cascade of centrifuges to demonstrate the advanced nuclear fuel. Under the contract, Centrus will license, build, assemble, and operate AC100M centrifuge machines and related infrastructure in a cascade formation to produce HALEU at the DOE’s American Centrifuge Plant in Piketon, Ohio, for the demonstration program.
The DOE earlier this year said it wanted to fast-track demonstration of HALEU production to help propel interest and bolster development of advanced nuclear reactor designs. HALEU is nuclear fuel that is enriched to a higher degree (of between 5% and 20%) in the fissile isotope U-235. In comparison, the world’s current fleet of light water reactors (LWRs) typically uses fuel enriched to less than 5% U-235. As experts note, HALEU promises to provide more power per volume than conventional reactors, and its efficiency allows for smaller plant sizes. It also promises longer core life and a higher burn-up rate of nuclear waste, it notes.
The Nuclear Energy Institute (NEI) says many advanced reactor concepts—including some microreactors (many smaller than 10 MW), high temperature gas reactors in the 100-MW to 200-MW range, and salt reactors—may require this type of fuel. HALEU could also be used in existing light water reactors. Massachusetts-based fuel company Lightbridge, for example, is developing HALEU for use in commercial fuel. It has said it wants to demonstrate the fuel in a research reactor at a U.S. national laboratory in 2020, as well as a commercial nuclear power plant powering a U.S. city by 2021, but, the DOE in May declined to fund the project, citing a lack of detail about Lightbridge’s commercial HALEU fuel product.
Though NEI suggests annual commercial requirements for HALEU could soar to a cumulative 185.5 metric tons annually, there is no current supply of HALEU, and commercial supply is not likely to materialize until a market is formed. NEI has long urged the federal government that establishing HALEU fuel production capability in the near future is critical to U.S. leadership, as global competition heats up to design and build small modular reactors as well as larger non-LWR reactors.
Deputy Secretary of Energy Dan Brouillette told reporters on Jan. 7 as he announced the AC100M HALEU demonstration project that national security is a key driver for the fast-tracked project. “Russia has the ability to produce these type of fuels,” which is why the U.S. government was “looking for U.S. origin and U.S. source fuel. We feel this is very important, again, for national security, for energy security needs here in the U.S,” he said. The project’s goal is “to demonstrate the capability to produce HALEU with existing U.S. enrichment technology in support of the advanced reactor community.” However, “it will also benefit research and development programs here at the department itself,” he said.
Brouillette, whom President Trump has suggested could replace current Energy Secretary Rick Perry when he retires, likely at the end of this year, said in January that the Centrus demonstration project is expected to produce 19.75% U-235 enriched product by October 2020. DOE documents, however, suggest that while construction could begin this year to balance the centrifuges, the project will likely be wrapped up in September 2021, even though the contract runs through 2022.
Centrus on Tuesday acknowledged the program has been underway since Centrus and the DOE signed a preliminary letter agreement on May 31, 2019, “which allowed work to begin while the full contract was still being finalized.”
Centrus, a government corporation designed to restructure the government’s uranium enrichment operations that was privatized in 1998, has already successfully demonstrated its advanced U.S. gas centrifuge uranium enrichment technology at the Piketon facility. That project, called the “lead cascade,” involved demonstrating the effectiveness of a DOE-developed, classified centrifuge design and equipment by processing uranium in a closed loop.
However, though the demonstration was successfully completed, Centrus struggled to remain financially viable amid snowballing cost pressures due to delays, and it made a financial decision to cease uranium enrichment operations in February 2016. The Nuclear Regulatory Commission (NRC) later downgraded licensed activities at the lead cascade project to “limited operations,” and removed its regulatory permission to enrich uranium. Centrus submitted a revised decommissioning plan in January 2018, and requested to terminate the facility in August 2018. The DOE’s newly announced contract with Centrus for the HALEU production demonstration appears to revive Centrus’ activity at the facility. The agency says the facility is in “excellent condition, ideally suited and immediately available” for the AC100M HALEAU demonstration program.
Centrus is now headed by Daniel B. Poneman, who served as deputy secretary of energy and chief operating officer at the DOE during the Obama years, from 2009 to 2014. Poneman joined the company as president and CEO in 2015. According its last 10-Q filing dated June 30, Centrus has $515.3 million in total assets and $873.6 million in liabilities.
According to the letter agreement it signed with the DOE in May, the DOE’s share of the project will be capped at $115 million, and Centrus would provide $29 million, bearing any costs above the demonstration’s current $144 million price tag.
But Centrus appears confident that its technology is ideally suited to produce HALEU. “We believe our technology offers the fastest, most economical route to U.S. production of HALEU—a fuel which will help improve the performance and economics of both new and existing reactors,” Centrus spokesperson Lindsey Geisler told POWER on Nov. 6.
“The costs will depend on the timing and size of demand, but we wouldn’t be investing in this program if we didn’t believe in the long term competitiveness of HALEU production.”
Development of TRISO Fuel Ramps Up
Along with the AC100M HALEU demonstration, the DOE is exploring recovery of high-enriched uranium (HEU) from used fuel from the 19-MWe EBRII (a demonstration reactor, that operated from 1963 and 1994) and then down-blending it to HALEU. That project could deliver 5 metric tons of a 19.75% U-235 enriched product by 2023, the DOE says. Another project the DOE is mulling involves the ZIRCEX process, which removes cladding from nuclear fuel and then purifies uranium from fission products using a “very compact, modular solvent extraction system.” The uranium is then down-blended to below 20% before solidification and fuel fabrication. The ZIRCEX program is still in the research phase, however, though the DOE may back a quarter-scale head-end pilot facility in 2020.
Meanwhile, the DOE is hosting the 5,000-square-foot TRISO-X pilot fuel facility at Oak Ridge National Laboratory under two active cooperative agreements with X-energy that allow the 2009-established Rockville, Maryland–based firm to manufacture TRISO particles.
According to X-energy, the TRISO fuel technology developed under the 2015 DOE Advanced Gas Reactor (AGR) Fuel Qualification Program, “start with a uranium kernel, which is coated with three layers of pyrolytic carbon and one layer of silicon carbide. These coatings encapsulate all product radionuclei under all operating conditions.”
But X-energy now wants to move toward commercializing the technology and build the larger TRISO-X Fuel Fabrication Facility, for which it partnered with Centrus last year to work on preliminary and final designs. To commercially produce HALEU enriched to 19.75%, however, the company will need an NRC Category II license for the fuel’s designation as a “special nuclear material” because it contains material enriched between 10% and 20%.
As X-energy CEO Clay Sell explained on Nov. 6, however, the “extremely high and unnecessary cost of working with HALEU in a Category I NRC facility has, in the past, limited TRISO’s economic viability in the marketplace,” he said. The company has so far identified a site for the commercial fuel facility and engaged with the NRC in Category II pre-application meetings. In parallel, the company is also developing an advanced reactor concept known as Xe-100, a 75-MWe (200-MWt) high-temperature gas-cooled pebble bed small modular reactor (SMR) that would use a 15.5% enriched HALEU. X-energy has initiated preliminary design and pre-application activities with the NRC, with plans for an operational facility in the 2023-2024 timeframe.
X-energy Vice President for Fuel Development Dr. Pete Pappano told POWER on Nov. 7 that the teeming agreement that X-energy and GNF announced on Nov. 6 to produce the nuclear fuel at GNF’s fuel fabrication facility aligns to the company’s regulatory engagement plan. Also, the “schedule enables X-energy and GNF to meet the Department of Defense and NASA fuel timelines for prototype reactors and subsequent deployment,” he said.
X-energy CEO Sell also suggested that the agreement could propel production sooner than if X-energy built TRISO-X. “Utilizing X-energy’s already operational state-of-the-art equipment in GNF’s licensed facility changes the dynamic for TRISO-fueled reactor deployment,” he said.
While details of the collaboration are sparse, GNF and X-energy claimed in the Nov. 6 joint statement that the opportunity could produce TRISO fuel of “significantly higher quality and at costs that are substantially lower than other potential manufacturers.”
Jay Wileman, president and CEO of GE Hitachi Nuclear Energy, which operates GNF, a company that is known as a supplier of boiling water reactor fuel and fuel-related engineering services, said the companies complement each other. “Combining X-energy’s technical knowledge and experience as the only current producer of TRISO fuel and GNF’s licensed operating facility and half century of commercial fuel experience and leadership make this a formidable team,” he said.
BWTX Gearing up to Restart TRISO Production
GNF and X-energy’s announcement comes a month after BWX Technologies (BWXT)—a company that supplies nuclear components, fuel, and technical services to the government—announced it would restart its existing TRISO nuclear fuel production line and expand its capacity within “approximately 12 months” by adding more equipment and staff at the nation’s only TRISO-licensed facility in Lynchburg, Virginia. The company plans to complete capacity upgrades and begin increased TRISO production within 24 to 32 months.
The company says it worked with the DOE for more than 15 years to develop and manufacture TRISO-coated kernels at the specialty fuel facility to support the government’s vision of developing “passively safe, compact nuclear reactors capable of economically generating electricity and hydrogen.” Under DOE’s Advanced Gas Reactor Fuel Development Program, it has also manufactured and certified TRISO-coated kernels and fuel compacts in production-scale quantities.
However, the company “halted TRISO production in the spring of 2017 after supplying its most recent batch of fuel for experiments at [Idaho National Lab’s] Advanced Test Reactor in support of DOE’s Advanced Gas Reactor Program,” a company spokesperson told POWER on Nov. 7. “We retained the processing equipment, production capability and the talented staff who performed this work.”
Echoing GNF and X-energy, BWXT said its existing TRISO production capability will position the company to meet emerging demand from Department of Defense micro reactors; NASA, for nuclear thermal propulsion requirements; and civil advanced reactors. Ramping up production capacity to meet demand is a priority, it suggested.
“TRISO production with HALEU requires at least an NRC Category 2 license, which can take several years and substantial investment to obtain. BWXT currently has the only private Category 1 licenses in the U.S., and they can also be utilized to produce Category 2 material,” it said. “The company’s existing infrastructure would contribute to far lower initial costs as compared to setting up a new TRISO production facility, and it will not significantly increase current decontamination and decommissioning liabilities,” it noted.
Expanding its capacity would be relatively less complex than building a new facility, it suggested. “BWXT already has the required safety, security, quality, material accountability, and operational systems needed to execute this work. The company can also leverage the expertise of hundreds of security-cleared engineers, trained uranium processing technicians and other professionals to quickly and safely ramp up to required production targets.”
—Sonal Patel is a POWER senior associate editor (@sonalcpatel, @POWERmagazine)