The Nuclear Regulatory Commission is requesting comments on the regulatory basis for a proposed rule for light water reactor fuel designs featuring high-assay low-enriched uranium (HALEU), including accident tolerant fuel (ATF) designs, and on draft guidance for the environmental evaluation of ATFs containing uranium enriched up to 8 percent U-235. Some of the HALEU feedstock for those LWR fuels and for advanced reactor fuels could be produced within the first Category II fuel facility licensed by the NRC—Centrus Energy’s American Centrifuge Plant in Piketon, Ohio. On September 21, the NRC approved the start of enrichment operations in the plant’s modest 16-machine HALEU demonstration cascade.

American Nuclear Society Executive Director/CEO Craig Piercy visited One White Flint North, where he sat down with U.S. Nuclear Regulatory Commission chair Christopher Hanson for a one-on-one interview on September 18, 2023. The interview is available exclusively to ANS members to watch this week before it is released to the public. ANS members won’t want to miss the hour-long discussion, where Hanson opens up about important topics facing the NRC and the nuclear community and what he sees as the big successes during his first term as chair.

Oklo Inc. and Centrus Energy announced a new memorandum of understanding on August 28 to support the deployment of Oklo’s microreactor design, dubbed Aurora, near the Piketon, Ohio, site where Centrus plans to operate a high-assay, low-enriched uranium (HALEU) enrichment demonstration under contract to the Department of Energy by the end of the year.

It’s been almost 35 years since Illinois last added a nuclear power reactor to the grid (Braidwood-2, a pressurized water reactor operated by Constellation, reached commercial operation in October 1988). And it’s been 63 years since a research reactor reached initial criticality at the University of Illinois–Urbana-Champaign (UIUC). The university’s TRIGA Mark II started up in August 1960 and was shut down in 1998. For about 25 years, UIUC—the flagship public university in a state that generates more power from nuclear energy than any other—has lacked an operating research reactor.

Advanced reactors are promising energy systems that can enable the world to transition to a more sustainable energy matrix. These concepts are potentially more fuel efficient and safer, compared with previous generations of nuclear reactors. Many designs, like high-­temperature gas reactors (HTGRs) and molten salt fast reactors (MSFRs), target high outlet temperatures, allowing for their operation in processes where high heating is required, such as for hydrogen production and desalination.

Nuclear thermal hydraulics—for light water reactors or advanced reactors cooled by gas, metal, or salt—is all about defining safety and performance margins as things heat up.

Five pronuclear organizations—the Breakthrough Institute, Clean Air Task Force, ClearPath, Nuclear Innovation Alliance, and Third Way—have together penned a letter to the Nuclear Regulatory Commission, calling on the agency to take action on its emergency preparedness for advanced reactors rule—which, despite the explosion of interest in these technologies over the past few years, has yet to be finalized.

A large, bipartisan group of Capitol Hill lawmakers last Friday wrote a letter to the members of the Nuclear Regulatory Commission urging them “to carefully review and modify as necessary” the 10 CFR Part 53 draft licensing framework for advanced nuclear reactor technologies.

Take note! Registration closes today for the U.S. Department of Energy Conference for Newcomers: Understanding Exports of Advanced Reactor Technologies, scheduled for July 26–27 at Argonne National Laboratory in Lemont, Ill.

Contact Mercedes Trent (mercedes.trent@nnsa.doe.gov) to sign up for the conference. Additional information will follow upon registration.

Advanced reactors may be key to a clean energy future, but to prove it they’re going to need fuel—and that fuel will be derived from limited uranium resources and managed throughout the nuclear fuel cycle, whether that cycle is open (like the current fuel cycle) or closed (with reprocessing). Six panelists convened on June 12 during the Annual Meeting of the American Nuclear Society for the executive session “Merits and Viability of Advanced Nuclear Fuel Cycles: A Discussion with the National Academies.” They discussed those fuel cycles and the findings of a National Academies of Science, Engineering, and Medicine (NASEM) consensus committee released as a draft report in November 2022 and published earlier this year.

At the 2023 ANS Annual Meeting, Steven Arndt (as of the close of the meeting, ANS immediate past president) led a president’s session on the mission of the Nuclear Regulatory Commission—a not particularly surprising topic, given that he spent over 30 years at the agency in various roles.

Sola Talabi

Advanced reactor risk management creates awareness, assessment, and action on issues of uncertainty to ensure safe, cost-effective, and on-schedule deployment of advanced reactors. It requires people, processes, and tools to identify and assess risks both qualitatively and quantitatively.

For safety risk, this requires characterizing how advanced reactor features such as natural convective cooling may reduce or retire risks. It also includes identifying and assessing new risks that may be introduced by advanced reactor features. Retired and reduced safety risks include certain loss-of-coolant accidents because the pumps and piping systems associated with these accident scenarios are eliminated. New safety risks that may be introduced include resuspension of fission products due to the higher containment aspect ratios that some advanced reactors have. New transportation risks may arise in the case of irradiated microreactors after service. Hence, advanced reactor risk assessments should include a mechanistic assessment of the net effect of the retired and new risks to quantitatively characterize overall plant safety. This may be achieved with probabilistic risk assessment procedures and tools.

The Department of Energy released two draft requests for proposals to acquire high-assay low-enriched uranium (HALEU)—one covering enrichment services that could include the production of between 5 and 145 metric tons of HALEU during a 10-year performance period, and another for deconverting that HALEU from uranium hexafluoride (UF₆) gas to metal or oxide forms in preparation for fuel fabrication. The DOE also issued a notice of intent to fulfill its National Environmental Policy Act (NEPA) obligations for the HALEU Availability Program by launching the scoping process for an environmental impact statement; that notice was published in the Federal Register on June 5.

Here is a recap of industry happenings over the past month:

ADVANCED REACTOR MARKETPLACE

Partnership formed to study X-energy’s SMR in commercial conditions

X-energy and Kinectrics have launched a partnership to design, build, and operate a commercial-scale test facility to study the performance of the Xe-100 advanced small modular reactor in helium--based high-temperature, high--pressure operating conditions. The test facility, the site for which is to be announced sometime this summer, may be completed and operational by 2025.

Reports released this week point to a clean energy future fueled by atomic energy—if and when pressing supply chain issues can be resolved. Advanced Reactor Roadmap, Phase 1: North America, released on May 15 by the Electric Power Research Institute and the Nuclear Energy Institute, takes a broad look at the deployment of advanced fission reactors and identifies supply chain ramp-up as one key enabler. The Fusion Industry Supply Chain: Opportunities and Challenges, released by the Fusion Industry Association on May 17, focuses on fusion energy supply chain issues.

Purdue University and Duke Energy released an interim report on May 10 that documents the first year of an ongoing feasibility study, first announced in April 2022, that could help bring nuclear power to the state of Indiana. No technology has been selected and no decision to build a new nuclear plant has been made at Purdue University or elsewhere in the state, but in the Small Modular Reactor and Advanced Reactor Feasibility Study Interim Report the study participants conclude that “small modular reactors and advanced reactors are a viable option that warrant continued exploration to meet the future carbon-free energy needs of Purdue University and Duke Energy Indiana.”

The Department of Energy yesterday announced the awarding of $22.1 million to 10 industry-led nuclear projects, including two aimed at expanding clean hydrogen production and one at advancing a microreactor design. Other projects selected for funding are focused on addressing nuclear regulatory hurdles, improving existing reactor operation, and facilitating new advanced reactor developments.

Abstracts for all 10 projects can be found here.

Richard Meserve, who for more than two years chaired the National Academies of Sciences, Engineering, and Medicine (NASEM) Consensus Committee on Laying the Foundation for New and Advanced Nuclear Reactors in the United States, introduced its 300-page report on April 27 during a public briefing.

NuScale Power and TerraPower both signed agreements earlier this week with South Korean entities to support development of the American firms’ respective reactor technologies.

Here is a recap of industry happenings over the past months:

ADVANCED REACTOR MARKETPLACE

Ultra Safe and Framatome reach TRISO agreement

Ultra Safe Nuclear and Framatome have signed a nonbinding agreement to manufacture commercial quantities of TRISO fuel for advanced reactor designs, including USNC’s Micro Modular Reactor. It is expected that the manufacturing of both TRISO fuel particles and USNC’s fully ceramic microencapsulated fuel will begin in late 2025, with production capacity being made available to the broader global commercial market. At-scale production lines for these materials have been demonstrated at USNC’s Pilot Fuel Manufacturing facility in Oak Ridge, Tenn., the first privately funded producer of TRISO fuel particles in the United States.