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.
Three of the executive session panelists served on the NASEM consensus committee—Paul Dickman of Argonne National Laboratory, Craig Hansen of Cadence, and Edwin Lyman of the Union of Concerned Scientists—and three served on an ANS ad hoc committee organized to review and comment on the NASEM report—John Kessler of J. Kessler and Associates, Christina Leggett of Booz Allen Hamilton, and Steve Nesbit of LMNT Consulting. The ANS committee released a letter in March detailing their observations on the NASEM report.
The panelists aired their differences and outlined their expectations of advanced reactor fuel cycles with session chair and moderator John Mattingly of North Carolina State University. (A NASEM “sister study,” “Laying the Foundation for New and Advanced Nuclear Reactors in the United States” was not part of the June 12 discussion. That consensus study report, introduced in a prepublication public briefing in April, discussed a range of technical, regulatory, economic, and societal challenges facing advanced reactor deployments—covering almost everything but fuel cycles.)
Agreement—and disagreement: Mattingly led off the session by outlining several points of agreement between the NASEM and ANS committees. Both agreed “that Congress and the [Department of Energy] should assure access to materials testing and fuel qualification facilities/capabilities, and that the United States needs to establish a domestic supply chain for HALEU. . . . They also agreed that the once-through fuel cycle should remain the de facto standard in the U.S. for the foreseeable future and that Congress should establish a single-mission entity that takes responsibility for the management and disposal of nuclear waste. Finally, the last point of agreement was that DOE, [the Nuclear Regulatory Commission], and [the Environmental Protection Agency] should work together to develop regulations and standards for a generic repository.”
“There were a handful of points where they did not agree,” Mattingly continued. “First of all, in terms of the general tone of report, the ANS committee felt that it did not address its mandate to evaluate the merits and viability, specifically, to advanced nuclear fuel cycles. It also conveyed, in their opinion, a negative outlook on the role of nuclear energy to meet the current and future U.S. energy needs, [and] it projected a pessimistic outlook on the proliferation risk associated with advanced reactors and their fuel cycles. And then finally it didn't account for existing NRC rulemaking on the physical protection of high-assay low-enriched uranium, or HALEU.”
The ANS committee also felt that a couple of points were missing from the report, Mattingly said: a recommendation on a standard fuel disposal contract for advanced reactor vendors and a recommended path forward for NRC rulemaking on the recycling of irradiated fuel from advanced reactors. After Mattingly set the stage, each panelist spoke in turn about their work and opinions on the NASEM report and the ANS letter before the discussion was opened to audience questions.
Dickman—HALEU in context: Paul Dickman described the context in which the NASEM committee undertook its two years of work. “One of the very first people that we interviewed as a committee was one of the people [who] actually wrote the language” directing NASEM to conduct the study—Christopher Hanson, who worked on the committee’s statement of task as a staff member of the U.S. Senate Appropriations Committee in late 2019 and offered testimony in September 2020 as a commissioner of the NRC (he was designated chair in January 2021). Hanson told the committee that as a Senate staffer, “they were being inundated daily by companies coming up there promoting their particular advanced reactors, [and] he was trying to separate the wheat from the chaff, and so that was really one of our charters—to try to provide a pragmatic view of what was going on.”
Dickman explained that the bulk of the committee’s information gathering was complete by January 2022. “Think about it,” he said. “In January of 2022 we recognized that our domestic LEU program and advanced reactor program were vulnerable to Russia. Well, guess what happened? In February 2022, Russia invaded Ukraine.” The Advanced Reactor Demonstration Program, including planned demonstrations of advanced reactor technology from TerraPower and X-energy, was planning to begin operations with HALEU purchased from Russia, Dickman explained, and that vulnerability had already been acknowledged during the committee’s information gathering. “The question became, after that invasion occurred, ‘What really substantially changed?’ And what I’d say is practically nothing [changed], because we didn't really have the programs and policies in place.”
Dickman outlined the nation’s limited choices for addressing the HALEU supply shortfall. In addition to waiting for HALEU from the DOE’s nascent HALEU Availability Program or drawing on already committed HEU stockpiles for downblending, “the third choice was basically you delay the [ARDP] program,” Dickman said. “And guess what, we already know that is exactly what's happening. So TerraPower has already announced that they're delayed . . . because the original plans were all dependent upon Russian HALEU.”
Hansen—Challenges require investment: Craig Hansen spoke to the broad scope of reactors considered by the committee, which included both light water–cooled and non-LWR designs.
“There are significant differences in the technical readiness of each of those categories of reactors,” Hansen said. “And I think that's something that the nuclear industry has to embrace if we’re really going to make long-term changes. We have to be realistic about what it's going to actually take to bring each of these types of reactors to the forefront.” In the NASEM committee, Hansen said, “some people wanted to group them all together and say, ‘They're advanced reactors and it's all going to be hard and it's all going to take time and none of them are going to be commercially viable for a long time.’ So we worked hard to kind of break those apart, and you'll see that language in the report.”
Hansen talked about what it will take to reach economies of scale on small modular reactors in a factory-built environment. For reactors of varied fuels and coolants, he pointed to the need for testing. “People who are developing advanced nuclear technologies need access to testing capabilities to test welds, to test materials, to test components, to prototype things, so that codes can be built so you can remove conservatisms that are associated with the operation of the reactor, and by removing conservatisms you can decrease the levelized cost of electricity,” Hansen said, before adding, “I would say, not only do we need [the Versatile Test Reactor], but if this is truly an existential issue, let's get one more, and we need to make sure that our test reactors have individual loops like the Advanced Test Reactor.”
When Mattingly asked the panelists to opine on the potential impact of the NASEM report, Hansen spoke of opportunity. “I think that the report’s impact is going to be largely dependent upon how people in this room and people within the industry react to it and what the message is that they take to Congress,” he said. “I wouldn't even be worried whether the report is negative or positive. It's an opportunity to get in front of the right people and talk about the issues that are necessary to be resolved for us to make progress on this existential issue.”
Lyman—Focusing resources: “I think it's a self-evident finding that advanced fuel cycles will have potentially different levels of risk than the current light water reactor fuel cycle, and that you will need to adjust safeguards and security commensurate with those risks,” said Edwin Lyman, as he began his remarks, which focused on nonproliferation security issues of advanced reactor fuel cycles.
“Most of the information we got suggested work on developing appropriate safeguards for these materials and facilities is at a very early stage and there really is no guarantee for these complex fuel cycles that they'll be a success, at least compared to the level of success for the current baseline [of the LWR fuel cycle]. . . . But I would say the report is actually a call to action by arguing that there needs to be more safeguards development and more active cooperation between the U.S. and the [International Atomic Energy Agency],” Lyman said.
Asked later by Mattingly to condense the potential impact of the report, Lyman commented, “When people make claims about the potential advantages of a particular technology—and we've all heard them—it's important that there has to be better peer review, better assessment of the realistic ability to meet those goals when you think about how to focus your resources. I think ultimately anything that provides guidance on how to shape that thinking is going to focus resources better and potentially lead to a more successful program.”
Kessler—A focus on waste management: “When we heard about this study many years ago, we knew that the topic was going to be of significant interest to a good chunk of [ANS] members,” said John Kessler, who at the time of the panel was chair of the ANS Fuel Cycle and Waste Management Division (FCWMD). “So Christina Leggett and I decided that we should put together an ad hoc committee to take a look at the report and see if there was anything we wanted to weigh in on.”
Kessler first drew attention to the back end of the fuel cycle and to ANS’s proposed generic disposal standard, which as of this writing is available in draft form. “Steve Nesbit tasked me to put together a group of people to come up with a proposed generic disposal standard. We’ve done so. We first talked about it at the High-Level Waste Management meeting last November, we received comments, and we expect it to be out the door—meaning on the ANS website—in late July,” Kessler said.
He then weighed in on how the NASEM report addressed different advanced reactor waste forms. “There are definitely different levels of development of fuel forms for different kinds of advanced reactors as they pertain to waste. TRISO . . . [probably has] advantages over the existing uranium oxide as a waste form. And there's been a lot of work done on TRISO.” So much work, Kessler said, that “NASEM actually had something to write about in an appendix regarding TRISO, so they talked about all the issues that needed to be provided, to be done, to go in to TRISO.
“Well, okay,” he continued, “but there are a lot of other waste forms they could have spent appendices on too, and we felt that was indirectly unfair, picking on TRISO, when it's probably one of the better waste forms [in terms of available scientific information].”
Kessler commented about the perceived negativity of the report, as several panelists did. “It reads like you can't get there from here,” he said, “and we all recognize at ANS that it takes a lot of resources to get there. What we found was missing . . . was there were a lot of good reasons why we should do this. Why we should strive to get some of these fuel cycles up and running and spend the money.”
Leggett—Moving toward a closed fuel cycle: After first making clear that she was sharing her own views and not those of her employer, Christina Leggett, ANS Board of Directors member and current FCWMD chair (as of the close of the Annual Meeting) added her own opinion on the NASEM finding—agreed to by the ANS ad hoc committee—that the current once-through policy will likely be the default fuel cycle moving forward.
“That's just like saying the current LWR system is going to be the default moving forward, because it takes time to develop and deploy these advanced reactors,” Leggett said. “But I don't think—and this is me speaking now—I certainly don't think it should continue. I think we should move toward the closed fuel cycle. I think it makes the most sense, especially in light of the fast reactors that can achieve higher utilization and reduce uranium requirements.”
Leggett addressed the nonproliferation concerns raised in the NASEM report, saying, “We've had several countries throughout history . . . that have been recycling plutonium and uranium for decades. And to my knowledge there is no proliferation of plutonium that's going on. I don't understand why there's so much emphasis on this [in the NASEM report].”
Leggett pointed to reprocessing as a means of ensuring a sustainable nuclear fuel supply. “I can tell you that . . . at La Hague [in France], the one large reprocessing facility that is currently operational, they decided to move on this path, to go on and do reprocessing, because, well, France doesn’t have their own uranium. . . . And in fact, for La Hague, they have a 25 percent reduction in uranium resource requirements.”
Leggett agreed with other ANS ad hoc committee members that the report took a negative perspective on advanced reactor prospects and costs. “The report spent a lot of time talking about the challenges, but I didn't get the sense that they were supportive of the advanced reactor fuel cycles and advanced reactors in spite of the challenges. So there weren't really recommendations to overcome the challenges. They would say. ‘Oh, it's too expensive,’ or ‘It takes a lot of investment to do this,’ but it didn't say you should go and do the investment. I didn't get that sense, except for in the case of HALEU.”
Nesbit—A track record of success: ANS past president Steve Nesbit (2021–2022) took exception with finding 4 in the NASEM report, which claimed that “most of the advanced reactors, especially the non–light water reactors, will confront significant challenges in meeting commercial deployment by 2050.”
“Being an engineer, I did some math. I did the calculation,” Nesbit said. “2050 minus 2023, that's 27 years. So that’s saying that we can't deploy these reactors in 27 years. I just don't believe that. I mean, I look at what happened between 1960, when Shippingport had been running for three years, and 1987, when virtually all of the commercial reactors in the U.S. had been constructed and built, and we’re producing huge amounts of electricity for this country. We’ve got 27 years and we’ve got this existential threat and we can't do that? That just boggles my mind.”
Nesbit also commented on the discussion of HALEU and nonproliferation in the report. “I do think that the HALEU issue was way overemphasized,” he said, noting that the report did not include information about the nuclear industry’s track record of safe management of the current nuclear fuel cycle.
“The first thing I want to do when I'm looking at something is ask, ‘What's the data?’” Nesbit said. “We've got data on how safe storage and transportation is. . . . We've got data on how effectively we can guard against proliferation . . . So yes, there are challenges out there associated with the advanced reactor fuel cycles. But the sky is not falling, Chicken Little, just because an acorn hit your head.”
“Probably the safest and most successful endeavor in the history of humankind is the storage and transportation of used nuclear fuel,” Nesbit added. “Nobody's ever been hurt as a result of a radiation release during one of these things. There's no mention in the report that the industry has a great record here. Instead, it's all about ‘Well, we've got new types of fuel, so it's going to be a real challenge.’ Sure, there's challenges everywhere, but we met the challenge, and we're going to meet it again.”