Several industry-led developments and a possible new advanced nuclear demonstration have been announced since the White House working group laid out a national strategy to revive the nuclear industry last week.

Centrus Energy on April 28 signed a letter of intent with Advanced Reactor Concepts (ARC), developer of a 100-MWe sodium-cooled fast-reactor design, that potentially secures the nuclear fuel supplier a first commercial customer for its high-assay, low-enriched uranium (HALEU) fuel supply. Holtec International, meanwhile, sealed a deal to adapt its SMR-160 design to Framatome GAIA assemblies.

These announcements come on the heels of a pivotal research and development agreement that will allow Lightbridge Corp.—a much-watched developer of an innovative metallic fuel technology—to design an experiment for irradiation of Lightbridge metallic fuel material samples at Idaho National Laboratory’s (INL’s) Advanced Test Reactor (ATR). On April 21, BWX Technologies said efforts to restart TRISO (TRIstructural-ISOtropic) manufacturing are progressing ahead of schedule.

And separately, on April 28, the Department of Energy (DOE) announced $5.4 million in funding awards to accelerate advanced nuclear technology development, including to support site preparation for a future advanced reactor demonstration in Portsmouth, Ohio. 

Centrus Potentially Snags First Commercial HALEU Customer

Though it is needed by many advanced reactor concepts, and it could boost the efficiency of existing reactors, HALEU—fuel comprising U-235 enriched to a higher degree (of between 5% and 20%)—is not commercially available today, nor are any HALEU-fueled reactors in commercial operation. “The lack of available HALEU constrains the deployment of advanced reactors and advanced fuels, and vice-versa,” Centrus Energy explained on Tuesday. “This is the ‘chicken and egg’ dilemma that must be resolved for the U.S. to establish itself as the global leader in building and fueling the next generation of reactors around the world, which is critical to U.S. influence on nonproliferation.” 

While it is non-binding and non-exclusive, Centrus Energy’s April 28 letter of intent with ARC is notable because it reflects a “long-term commitment to enter into a purchase agreement” for commercial HALEU supply that would meet ARC’s 2028 commercialization timeline for the ARC-100. 

ARC’s small fast-reactor is derived from the U.S. government’s Experimental Breeder Reactor-II that operated between 1961 and 1994. As the company told POWER on April 29, it garnered the Canadian provincial government of New Brunswick’s affirmation to build a first project at the Point Lepreau Generating Station in Saint John last December. “The province of New Brunswick was visionary in its funding of our proven technology and as such, ARC Canada, a subsidiary of Advanced Reactor Concept (ARC LLC) is entering into Phase 2 of the Vendor Design Review process governed by the Canadian Nuclear Safety Commission,” it said. “Our tentative deployment schedule is for 2028, with construction beginning tentatively in 2025,” the company said, noting that it will need first fuel by 2027 to meet the ambitious schedule. 

Unlike existing light water reactors (LWRs), which must be refueled with low-enriched uranium (LEU) every 18 to 24 months, the HALEU core of the ARC-100 will allow the reactor to operate at full power for 20 years without refueling, it added. Along with providing fuel for the Canadian project, the letter of intent with Centrus will allow the company to cooperate in potential HALEU supply initiatives for “worldwide deployment of the ARC-100 technology,” it said. 

The letter of intent is as significant for Centrus, a company that until 2014 was known as U.S. Enrichment Corp. (USEC). Created in 1992 as a government corporation to restructure the government’s uranium enrichment operations, USEC was privatized in 1998. Though it successfully demonstrated its advanced U.S. gas centrifuge uranium enrichment technology in 2013 (in a three-year project that ended in 2016) at the DOE’s American Centrifuge Plant in Piketon, Ohio, USEC struggled to remain financially viable amid snowballing cost pressures due to delays and challenged demand for enriched uranium in the post-Fukushima market. In 2016, two years after USEC reemerged from bankruptcy rebranded as Centrus Energy, the Obama administration defunded the demonstration cascade at the American Centrifuge Plant, and it was shut down. 

Centrus’ 120-machine demonstration cascade, which operated at Piketon until 2016 Source: Centrus

In May 2019, however, the DOE extended the lease agreement for Centrus’s Piketon facility until May 2022, and in late October 2019, it finalized a three-year $115 million (80%-20% cost-shared) contract that allows Centrus to deploy a small cascade of 16 AC-100M centrifuges at the American Centrifuge Plant to demonstrate production of HALEU by 2022. Though the COVID-19 pandemic has limited operations at the Piketon facility, the company says it is working toward a May 2022 demonstration timeframe. 

By the time the contract ends—and assuming the Nuclear Regulatory Commission (NRC) grants modifications for a commercial plant—Centrus expects to have fully licensed, operable HALEU production capability. Initially, while that capability will be at “a small scale,” it could be expanded “modularly” to meet commercial or government needs for HALEU, it said on Tuesday. 

Still, Centrus notes that there are no guarantees about whether or when government or commercial demand for HALEU will materialize—and it acknowledges that there are a “number of technical, regulatory and economic hurdles that must be overcome for these fuels and reactors to come to the market.” However, the company is optimistic about its investment in HALEU technology. “By investing in HALEU technology now, and as the only domestically-owned company with HALEU enrichment capability, we believe the [company] could be well positioned to capitalize on a potential new market as the demand for HALEU based fuels increases with the development of advanced reactors,” it said. 

BWXT’s TRISO Manufacturing Restart Ahead of Schedule

BWXT, the only U.S. company that has the required licensing to manufacture irradiation-tested uranium oxycarbide TRISO fuel at production scale, meanwhile, is ramping up efforts to restart its existing TRISO fuel production capabilities at its Lynchburg, Virginia, facility to meet emergent client interests, such as for Department of Defense microreactors, space reactors, and civil advanced reactors. 

While it still has no commercial power-producing users, production of TRISO—a type of HALEU fuel—is seeing a resurgence of interest in the U.S., where it was first developed in the 1960s for gas-cooled reactors, and around the world. TRISO’s biggest benefits are that it can withstand extreme heat, and has low proliferation concerns and environmental risks. “TRIstructural refers to the layers of coatings surrounding the uranium fuel kernel, and ISOtropic refers to the coatings having uniform materials characteristics in all directions so that fission products are essentially retained,” explained BWXT. 

While BWXT worked with the DOE for more than 15 years to develop and manufacture TRISO-coated kernels at its Lynchburg, Virginia, facility, under the DOE’s Advanced Gas Reactor Fuel Development Program, it “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. Last October, the company began preparing to restart production of its TRISO fuel, which has already undergone safety testing at up to 1,800C—which is “much higher than the standard operating temperature of reactors,” BWXT noted. 

More recently, the company said it has demonstrated the capability to form and sinter uranium oxycarbide (UCO) fuel kernels, which serve as a precursor to the TRISO coating process. “Sintering is a process by which heat and pressure are applied to form a solid fuel kernel,” it explained. “With the completion of these activities, BWXT is now focusing on bringing two additional furnaces online (an additional sintering furnace and a coating furnace) to meet projected production demand before restart activities are complete,” it said. 

Lightbridge Signs R&D Agreement Under GAIN Initiative

Meanwhile, on April 27, Lightbridge Corp.—a company that is developing a metallic fuel technology that relies on innovative helical multi-lobe fuel rods to improve the economics, safety, and proliferation resistance of existing and new reactors—announced it signed a cooperative research and development (R&D) agreement under the DOE’s Gateway for Accelerated Innovation in Nuclear (GAIN) initiative. The agreement with Battelle Energy Alliance, (which serves as INL’s) operating contractor, will allow Lightbridge and DOE researchers to design an experiment for irradiation of Lightbridge metallic fuel material samples at INL’s ATR. 

It will essentially entail a year-long project during which Lightbridge and INL plan to establish a test plan for measuring key thermo-physical properties of Lightbridge’s fuel material both before and after irradiation in the ATR. “INL will then perform the detailed design and establish the safety case for the experiment in the ATR. This will include the control of parameters such as thermal hydraulic capacity, maximum sample temperature, neutron fluence, and the physical location of the test capsules within the ATR. The output of this project will be the complete design and safety case needed for insertion of the experiment into the ATR,” the company said.

The development for Lightbridge marks another crucial stride in the company’s efforts to commercialize its technology, which it says can be applied to a wide variety of market segments, to include water-cooled commercial power reactors, such as pressurized water reactors (PWRs), boiling water reactors (BWRs), Russian-type VVER reactors, CANDU heavy water reactors, water-cooled small modular reactors, as well as water-cooled research reactors. Last December, it released a video demonstrating its co-extrusion manufacturing process using surrogate materials to produce full commercial-length fuel rods for large LWRs and SMRs. The actual fuel rods will use a uranium-zirconium alloy.

More recently, Lightbridge received a patent from the European Patent Office related to an assembly design for use in CANDU-type reactors. “It is our goal to bring Lightbridge Fuel to market as quickly, and at the lowest cost to stockholders, as practical,” Seth Grae, Lightbridge Corp. president and CEO wrote in a letter to shareholders on Tuesday. “We are designing the fuel to make existing reactors able to compete and win financially against natural gas, renewables, and other nuclear fuels. Lightbridge Fuel is also compatible with and can further improve the economics of new smaller, safer reactor designs that will significantly increase the amount of carbon-free energy.” 

The GAIN voucher—Lightbridge’s first DOE funding award—is a crucial step that will  “further validate” Lightbridge’s fuel technology and position the company to “advance in our development and commercialization efforts,” Grae said. “The federal government has made nuclear technology a strategic priority. We believe that demonstrating excellent performance under the GAIN program, along with demonstrating the value that Lightbridge’s technology offers to DOE, will be helpful in future grant applications.”

Holtec Selects Framatome as Fuel Supplier for SMR-160 

Sidestepping the many hurdles industry faces as it attempts to establish a commercial HALEU nuclear fuel supply, Holtec International is taking a different approach for the core design of its SMR-160 small modular reactor offering. On April 28, it selected French nuclear technology giant Framatome to supply standardized PWR fuel through its commercially available 17 x 17 GAIA fuel assembly. 

Introduced in 2012 to boost performance and provide high safety margins for increasingly demanding conditions at nuclear plants—including higher burn-up, lower neutron leakage, longer cycle lengths, and more challenging water chemistry conditions—Framatome’s GAIA fuel assembly design has been widely deployed, and, as the company told POWER in February, is thriving in the U.S. market. Framatome last year also deployed the fuel assembly design to test enhanced accident-tolerant fuel (ATF) pellets and cladding at Southern Nuclear’s Vogtle 2 reactor in Georgia. 

Work to refine Holtec’s 160-MW light water–based pressurized SMR design is continuing with partners including Mitsubishi Electric, SNC-Lavalin, and Exelon Corp. As Joe Delmar, senior director of Holtec International Government Affairs and Communications told POWER on April 29, completion of the final SMR-160 design “depends on a client-driven project (client need), but we expect completion of detailed design (ready to construct) in 2022.” Holtec is working to seek a license in partnership with a client, he said, and it is following a conventional two-step process that has been used to build all currently operating commercial nuclear plants. For now, the company expects the first license to build an SMR-160 plant may be issued by the U.S. NRC or the Canadian Nuclear Safety Commision. 

“We’re discussing potential deployments [with] Ontario Power Generation and several other utilities in Canada,” noted Delmar. “We’re also discussing potential deployments with several utilities in the U.S., including Tennessee Valley Authority. Our initial site expected for deployment in Ukraine remains slated as the Rivne site.”

By selecting a standard PWR fuel, Holtec said it has now reduced “the majority of the first-of-a-kind engineering for the fuel system,” as well as boosted its licensing and deployment potential. The choice also substantially eliminates risks associated with nuclear fuel, and ensures “fuel-related operational experience from the current light water reactor fleet operating worldwide is relevant to our reactor,” it said. Critically, it also ensures that prospective SMR-160 plant owners will have ready access to a robust international fuel supply chain, it said. 

The selection also has an interesting intersection with a February 2018 collaboration agreement Holtec signed with GE-Hitachi Nuclear Energy (GEH), which suggested the two companies would explore, among other things, whether GEH’s BWR fuel was suited to the design type. GEH in January launched a licensing process for its own BWR small reactor, the BWRX-300, suggesting the technology could be deployable by 2028. In response to a question about whether the deal for Framatome PWR fuel affects the GEH collaboration agreement, Delmar said: “Our agreement with GEH considers a broad scope of potential support and is not necessarily in conflict with our agreement recently announced with Framatome.”

DOE Announces Funding for Future Nuclear Demonstration

On April 28, the DOE announced it would award Waverly, Ohio–based Southern Ohio Diversification Initiative (SODI) $5 million to begin developing of an early site permit (ESP) template that will “envelope a broad range of advanced reactor technologies potentially supporting the DOE goal of demonstrating an advanced reactor by the late 2020s.” Work under that project will include characterization, permitting, and decontamination and decommissioning studies to support a potential advanced reactor deployment at a site in Portsmouth, Ohio, the DOE said.

SODI is a economic development initiative tasked with improving the quality of life for Jackson, Pike, Ross, and Scioto Counties through development of underutilized land and facilities at the DOE’s Portsmouth Gaseous Diffusion Plant Site, federal land which spans nearly 4,000 acres just south of Piketon, Ohio. 

The Portsmouth Gaseous Diffusion Plant  (the DOE’s acronym for the facility is “PORTS”), which occupies about 1,200 acres of the site, operated from 1954 to 2001. It was one of three large gaseous diffusion plants in the U.S. initially constructed to produce enriched uranium to support the nation’s nuclear weapons program, and in later years, enriched uranium used by commercial nuclear reactors. Clean up at the site began in 1989, and decontamination and decommissioning began in 2011; both continue today. The site also hosts the American Centrifuge Project, where Centrus is seeking to demonstrate HALEU. 

Details about the project are sparse (POWER has reached out to the DOE and will provide updates if/when received), but as a letter sent by Ohio lawmakers to the DOE in March 2019 suggests, community leaders have urged the DOE to pay attention to a competitive application submitted by SODI for the funding under the DOE’s Advanced Reactor Development Projects grant program. According to that letter, SODI will collaborate with Orano, Framatome, Southern Co., Duke Energy, and the Electric Power Research Institute to use the site. 

Sonal Patel is a POWER senior associate editor (@sonalcpatel, @POWERmagazine).