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Abstract

Nuclear power continues to offer the potential to be a major, worldwide, scalable, carbon-free energy source—if the challenges of safety, nonproliferation, waste management, and economic competitiveness are addressed. The international community has spent decades attempting to find a pragmatic approach to address waste-management concerns. Along the way, the advocates of open and closed nuclear fuel cycles have engaged in a running debate. For those who favor an open cycle, Sweden and Finland serve as excellent models today for successfully navigating both technical issues and public opinion to dispose of their spent nuclear fuel in a permanent repository that does not allow used fuel to be retrieved. But these successes have yet to be replicated elsewhere. For closed-cycle advocates, economically convincing technology solutions have yet to surface; as a result, leading reprocessing advocates claim that the future value of accumulated waste material can provide the economic justification for nuclear recycling. The authors discuss a middle-ground path that encourages research and development on advancements in fuel cycle technology while providing for safe waste storage on a century-long, or intermediate, timescale. Acknowledging the risks of pursuing such a venture, the authors also write on the importance of establishing performance metrics that would support nuclear energy as a sustainable, secure, and safe energy choice. The authors argue that the most important metric is the establishment of a surety index that could capture the nonproliferation and security risks of alternate fuel cycles.

Keywords

cask storage nonproliferation nuclear fuel cycle nuclear recycling nuclear reprocessing nuclear storage nuclear waste regional storage

More than half a century after the birth of commercial nuclear power, the back end of the nuclear fuel cycle remains problematic, for a host of technical, political, economic, and proliferation-related reasons. Among those countries that have chosen an open fuel cycle—in which fuel is only used once before it is removed from the reactor and stored indefinitely—only Finland and Sweden have successfully navigated through technical and political shoals and created permanent repositories to hold spent nuclear fuel. In other countries with once-through fuel policies—including the United States, which has engaged in decades of repository politics to no effect—used-fuel assemblies accumulate at nuclear power plants, posing safety and security risks. Meanwhile, the countries that have sought to reprocess nuclear fuel and create closed cycles have not found an approach that is broadly accepted internationally as both economically robust and adequately proliferation-resistant.

These fuel cycle dilemmas pose economic and security challenges that need to be resolved if nuclear power is to continue as a major world electricity source. We, the authors, support a phased, regionalized approach for long-term nuclear waste storage in the United States and elsewhere (Goldberg, 2012; Goldberg et al., 2012). Recognizing the growing global market for civilian nuclear power, we suggest that internationally supervised storage of used fuel at a relatively small number of consolidated sites—focused initially in East and South Asia, where storage problems are becoming acute and interest in reprocessing is strong—could potentially eliminate the expense and risk of managing multiple storage sites, many of them at nuclear power plants (Goldberg et al., 2012).

Such an approach could provide safe storage for a century or so, allowing time for continued research and development into fuel reprocessing methods that might improve the prospects for an economical, safe, secure, and safeguarded system. In those countries pursuing an open cycle, this regional storage system would provide time to reach political and technical consensus on permanent repositories. Before such a complex, politically difficult approach is pursued, however, the countries with nuclear power systems and their nuclear industries will need to establish performance metrics that allow them to demonstrate that they have addressed the significant safety, nonproliferation, waste management, and economic-competitiveness challenges commercial nuclear power now faces.

The economic and political benefits of interim storage

Given that the majority of established nuclear states have yet to commit to an ultimate waste-disposal solution, consolidated dry cask storage—in which used-fuel assemblies are placed in airtight containers surrounded by radiation shielding and stored at regional centers—could become an efficient and safe way of handling spent fuel on an interim basis.¹ Right now, most used fuel is stored in cooling pools at nuclear power plants; many of those pools are nearing capacity. Above-ground dry cask storage has been demonstrated to be economically advantageous, environmentally benign, and safe.

Consolidated dry cask storage at regional sites that accept waste from multiple power plants and even multiple countries would provide an interim solution that nuclear electricity producers could use while nuclear industry stakeholders develop technological solutions and nuclear nations make political decisions. This storage concept thus provides breathing room, giving current research and development activities in permanent storage and advanced fuel cycle technology time to mature. This interim storage system also would allow nuclear producers access to used fuel, should reprocessing technology advance, making what had been waste into an energy asset.²

Many plants within established nuclear power states—for example, Taiwan, Mexico, and Brazil—have produced relatively small quantities of used fuel; establishing dedicated dry cask storage facilities within each of these nations would be economically unattractive.³ That is, these emerging states would benefit politically and economically from shipping used fuel to a safe regional location that would be under international safeguards and enjoy the economies of scale associated with the larger quantities of used fuel such a facility would deal with.

The proposed regional consolidated storage facilities in no way reduce the necessity of developing final use and disposal options; they simply allow existing and new reactors to operate while permanent solutions are developed. Furthermore, a regional facility obviates the internal political challenge for the nuclear utilities and their advocates in selling an in-state disposal site.

In arriving at this regional approach to consolidated storage of used nuclear fuel, we considered how stakeholders—customers, fuel suppliers, and host states, among others—would address three key questions.

Will the price and supply of uranium support interim storage?

Currently, uranium sources are abundant, and using conventional technologies to reprocess spent fuel for re-use is more expensive than simply relying on these plentiful natural uranium supplies. Based on estimates of the world’s economically accessible uranium resources, the existing reactor fleet could run for tens of decades at current rates of consumption. That is, given that the fleet of present-day reactors requires about 70,000 to 80,000 metric tons of natural uranium per year, estimates of identified and undiscovered natural uranium could provide a roughly 215-year supply at today’s consumption rate (Nuclear Energy Agency, 2011). This estimate does not include other potential secondary supply sources, such as extraction of uranium from seawater, recycled depleted uranium, and blended-down weapons-grade uranium. On a timescale covering the next several decades, a uranium-based fuel cycle appears to be sustainable; furthermore, an indication of how demand can drive increased resource discovery is illustrated by the fact that known uranium resources have almost tripled from 1972 to 2012 (World Nuclear Association, 2012). Thus, the promotion of conventional reprocessing technology by firms such as France’s Areva seems to be largely motivated by the desire to fill existing capacity requirements, rather than by bottom-line economics or fears of imminent natural uranium supply depletion.

Can interim storage proceed before final waste disposition options are known?

Interim storage provides flexibility, allowing the fuel supply network future access to stored waste. Such access would allow nuclear suppliers, operators, and states to pursue any back-end approach that could be economical, sustainable, and more proliferation-resistant than the current plutonium uranium extraction (PUREX)-based fuel cycle or its variants.

Does conventional reprocessing capacity limit any other back-end solution?

When nuclear countries and companies move toward conventional reprocessing, they do not foreclose future waste-storage options; the waste products of fuels derived in part from conventionally reprocessed waste materials can be co-located at a repository with the spent fuel derived from any of the available open fuel cycles. In fact, the minor actinides remaining in processed waste dominate the repository heat load for the first few thousand years of storage at a repository.⁴ Conventional reprocessing pulls out only the major actinides—i.e., plutonium and uranium—and therefore does not have a large impact on the potential packing density within, and ultimate capacity of, a repository.⁵

No one-size-fits-all answer addresses all the questions about the back end of the nuclear fuel cycle. Regional consolidated storage does provide the economies of scale needed for an interim solution, but significant start-up capital would be required.⁶ Also, any regional solution would need to meet the needs of both those states that have generated used fuel in the past (the so-called legacy holders) and the emerging nuclear states. And a regional interim storage plan would have to serve the interests of nuclear states in East and South Asia, where on-site used-fuel storage is a particularly pressing problem.

Regional storage in Asia: A first step?

In view of the difficulties all experts identified in using multiple sites for long-term storage of used fuel, and considering the preference for keeping reprocessing options open, consolidated regional storage seems a particularly apt way of dealing with both legacy and newly generated used fuel in South and East Asia.

On-site storage of used nuclear fuel is a significant issue now in the case of Japan and South Korea and will be equally significant in such countries as Malaysia and Singapore. Taipower in Taiwan is facing similar concerns.⁷ During our preliminary discussions with scholars in South and East Asia, it became clear that the general sentiment in those regions supports the notion that countries in good standing with the International Atomic Energy Agency should not arbitrarily foreclose reprocessing options.⁸ But Asian experts we consulted also preferred a deferral of final choices on reprocessing technology, pending further research and development,⁹ particularly in view of the need to reduce the future nuclear waste burden. Still, the nuclear processing option cannot be ignored: In a number of Asian countries, progress toward any realizable nuclear waste storage solution will not occur unless respect is shown to the view that some type of nuclear waste reprocessing might ultimately be necessary or desirable.

In East Asia, three significant, intertwined events should prompt more attention to implementation of a viable back-end concept. First, there was no final resolution on the status of ongoing pyroprocessing research and development in the recent US–South Korea nuclear cooperation, or “123 agreement.”¹⁰ In Japan, meanwhile, the government shows increasing interest in starting the long-delayed fuel reprocessing plant at Rokkasho.¹¹ And the China National Nuclear Corporation (CNNC) and Areva recently signed a letter of intent to deploy modified PUREX technology early in the next decade in China.¹²

A viable international program of regional storage, coupled with a forward-looking nonproliferation research and development program, would address the issues being debated in South Korea and Japan. In the latter case, it would address Japan’s used fuel challenges without forcing the Japanese to change their recycling policy. A game-changer breakthrough in used-fuel treatment that includes convincing, proliferation-resistant technology could be a huge factor in mitigating proliferation risks in China and elsewhere. Providing regional used-fuel storage could create the incentive that persuades countries in this volatile region to delay their pursuit of reprocessing.

Doing business in the civilian nuclear domain in a regional context is, admittedly, difficult.¹³ The spectrum of stakeholders with different, and sometimes conflicting, interests is broad. The liability concerns are complex, particularly if multiple countries are involved in the ownership or operation of the regional facility, and if a variety of transportation scenarios need to be considered.

When it comes to regional storage, the litmus test for the nuclear industry will be the willing participation of the financial community. If the markets are to have an interest in lending for regional storage facilities, firm contracts with legacy used-fuel holders will have to be in place. Thus, a staging mechanism, involving the development of a business strategy document and a model contract with legacy holders, is a necessary first step. Many of the legacy holders would also likely want, at the least, a significant research and development program to be part of the overall deal.¹⁴

In our US-centric study, we proposed two pilot facilities, one for storage and another for disposal. In concert with creation of these pilot storage facilities, research and development efforts would be restricted to improved waste transportation, storage, and long-term disposal packages. This kind of proposal—aimed at a US nuclear waste solution unlikely to include reprocessing—would likely be insufficient to attract international legacy holders such as Japan, South Korea, and Taiwan to a regional storage plan. A more expansive research program that addressed chemical partitioning or advanced burn concepts would likely be needed.¹⁵

Back-end performance metrics and the future of nuclear power

Nuclear energy continues to offer the potential to be a major worldwide, scalable, carbon-free energy source—if its safety, nonproliferation, waste management, and economic-competitiveness challenges are addressed. Before significant investments in advanced nuclear technologies are made, however, nuclear states and nuclear firms should establish specific performance metrics that address each of these challenges. Nuclear stakeholders should also create a program of periodic assessments to determine how well the industry is performing vis-à-vis those metrics.

To assure investors of the industry’s long-term viability, at a minimum nuclear stakeholders will need to establish indices that consider a combination of safety, security, and safeguards criteria, and that allow comparisons between the established once-through fuel cycle and alternate fuel cycle programs. One possible approach is the creation of a surety index—that is, a measure of safety, security, and safeguards control of fissile material—along the lines of procedures established by Energy Department and Defense Department for their nuclear weapons and surety program (US Department of Energy, 2006). Such an index could include the deployment of transformative technologies that aim to detect and deter illicit use of fissile material produced via advanced reprocessing techniques.

Performance indices that focus on back-end economics would also be useful. For example, it is more than worthwhile to consider whether recycling used nuclear fuel is an economically sensible approach, in light of local economic conditions, the state of relevant technologies and repository development, the availability of fresh uranium fuel, and the importance placed on a nation’s energy security.¹⁶

Among the many experts with whom we have spoken, there is general agreement: A business and nonproliferation case compelling enough to drive used-fuel generators to reprocess and recycle requires significant technology advancement. Trying to force particular back-end outcomes at this point, therefore, strikes us as premature. For these many reasons, storing used fuel at internationally supervised regional storage sites—where transformational research and development can be done on waste forms and business strategies for managing used fuel—seems an appropriate and politically and practically achievable interim solution to nuclear power’s back-end problem.

Footnotes

Acknowledgements

The authors wish to gratefully acknowledge the significant contributions of the experts consulted in the South and East Asia regions during the course of this research. In particular, we thank James Malone of Lightbridge Corp. and Joosang Lee of TÜV SÜD Kocen, who are making important contributions to our understanding of both the institutional and business requirements in developing a regional consolidated storage proposal. The statements made and views expressed in this publication are solely the responsibilities of the authors and are not necessarily those of the officers and fellows of the American Academy of Arts and Sciences, the foundations supporting the Global Nuclear Future Initiative, the United States government or any agency thereof, the Argonne National Laboratory, or the University of Chicago.

Editor’s note

This article was inspired by two papers that the authors published in 2012 for the Energy Policy Institute at the University of Chicago (Goldberg, 2012) and the American Academy of Arts and Sciences (Goldberg et al., 2012).

Funding

This research is made possible by the American Academy of Arts and Sciences’ Global Nuclear Future Initiative.

Notes

Author biographies

Robert Rosner is the William E. Wrather Distinguished Service Professor in the Department of Astronomy and Astrophysics and Department of Physics at the University of Chicago. Previously, Rosner was the director of Argonne National Laboratory, where he also served as chief scientist. His research is mostly in the areas of astrophysical and laboratory fluid dynamics and plasma physics; more generally, he has been involved in the development of modern high-performance computer simulation tools, with a particular interest in complex systems. Within the past few years, he has also been increasingly involved in energy technologies, and in the public policy issues that relate to the development and deployment of those technologies. He is the founding director of the Energy Policy Institute at Chicago (EPIC), located at the Harris School of Public Policy Studies and Booth School of Business of the University of Chicago.

Stephen M. Goldberg until recently served as a senior technical advisor to the Nuclear Energy Division, and previously as special assistant to the director at Argonne National Laboratory. In these positions, he conducted systems studies on the economic competitiveness of nuclear energy (2004), on nuclear energy in Poland (2007), and on cogeneration in Jordan (2009). Previously, he served in the US government for more than three decades. While at the Office of Management and Budget, he received the Executive Office of the President’s highest award for efforts to complete several major international nuclear nonproliferation agreements, including the multibillion-dollar US purchase of highly enriched uranium extracted from former Soviet Union nuclear weapons. He is a senior fellow at the Energy Policy Institute at Chicago (EPIC) and is consultant to the Global Nuclear Future Initiative of the American Academy of Arts and Sciences.

References

Goldberg

(2012) Building the business case for restructuring the civilian used nuclear fuel management program. July 19. Available at: http://epic.uchicago.edu/i/publication/Building_the_Business_Case-2012.pdf.

Goldberg

Rosner

Malone

(2012) The back-end of the nuclear fuel cycle: An innovative storage concept. American Academy of Arts and Sciences, March. Available at: www.amacad.org/multimedia/pdfs/publications/researchpapersmonographs/backend.pdf.

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