The Back-End of the Nuclear Fuel Cycle: An Innovative Storage Concept
Appendix II: Key Issues for the Back-End of the Nuclear Fuel Cycle
Seven macro propositions52 about the nuclear fuel cycle, in general, consistently arise in conversations on the back-end of the nuclear fuel cycle, in particular.
- Uranium is either scarce or too expensive. Based on estimates of the world’s economically accessible uranium resources, the existing reactor fleet could run for more than 200 years at current rates of consumption. That is, given that the fleet of present-day reactors requires about 70,000 to 80,000 MT of natural uranium per year, estimates of identified and undiscovered natural uranium totaling 16 million MT would provide a roughly 215-year supply at today’s consumption rate. This estimate does not include extraction of uranium from seawater, which could potentially make available 4.5 billion MT of uranium—a 60,000-year supply at present rates. Thus, on a timescale covering the next several decades, a uranium-based fuel cycle appears to be sustainable.53 On the cost side, supply and demand for uranium will determine prices in the long run. Long-term prices have recently been trading in the $50 to $75 per pound range and do not have an impact on choices for or against nuclear energy.54 Thus, while there is the potential that the number of reactors will grow significantly—increasing capacity to somewhere between 400 and 500 GWe and causing the demand for uranium to rise markedly and result in higher costs for uranium ore—the price of uranium is not likely to be a critical factor in determining the practical deployment and sustainability of nuclear power.55
- The economic penalty associated with conventional reprocessing and recycling is outweighed by the noneconomic benefits that would accrue. In the past, advocates of conventional reprocessing have emphasized its contributions to extending fuel supplies and increasing energy-supply security. Today, the principal claim is that conventional aqueous reprocessing (that is, chemically partitioning the fissile material56 and relatively small quantities of related actinide materials from the waste products) will facilitate and simplify the management and disposal of nuclear waste. To fully understand this assertion, it is important to ascertain how large the cost penalty associated with conventional reprocessing and/or recycling is likely to be. We cannot determine an exact answer because some of the most important contributing factors are uncertain or otherwise difficult to estimate. The greatest source of uncertainty, with the largest impact on overall cost, is associated with the chemical partitioning process itself. Other important uncertainties center on the cost of MOX fuel fabrication and the relative cost of disposing reprocessed HLW as compared to the direct disposal of used fuel.57 However, if technology for advanced reactors included safer, more economic designs, and if these technology advancements included meaningful actinide consumption opportunities, the heat load and toxicity of the HLW stream would be substantially reduced. This key benefit of closing the fuel cycle (a benefit that is normally not included in costs for near-term back-end fuel services) would be a waste disposal game changer: specifically, it would jettison the siting of multiple HLW repositories,58 one of the most contentious public policy bottlenecks that influence public acceptance of nuclear energy expansion.59 As long as uranium prices remain in the $50 to $75 range60 and, more important, as long as we lack deployable, cost-effective technologies to change dramatically the approach to waste disposal, the benefits of treating used fuel are not sufficiently compelling today.
- Because fuel cycle expenses account for less than 10 percent of the total cost of nuclear electricity from unamortized nuclear power plants (capitalrelated costs account for most of the remainder), adopting a more expensive fuel cycle scheme that includes more advanced chemical partitioning techniques (that is, above and beyond conventional reprocessing technology) and fabricating MOX fuel would have a very small impact on the levelized cost of electricity paid by consumers of electricity. A long-term interim storage option may be a preferred alternative; this approach could be viewed as a long-term financial hedge if uranium prices spike and there are economical, safe, and secure technologies to close the nuclear fuel cycle.61
- The current infrastructure (capacity that has already seen significant investments) for all types of chemical partitioning facilities is not fully utilized. To date, approximately 90,000 MT (of a total 290,000 MT) of used fuel has been conventionally reprocessed. Annual conventional reprocessing capacity is now approximately 5,600 MT per year, and some of this capacity is underutilized.62 Already deployed (though not necessarily operating) capacities include La Hague, France (1,700 MT/yr); Sellafield, United Kingdom (2,350 MT/yr); Mayak, Russia (400 MT/yr); Rokkasho, Japan (800 MT/yr); and Kalpakkam, India (275 MT/yr). Additional capacity could be deployed for both aqueous and pyrometallurgical processes.63 There are expansion opportunities at the French and Russian facilities. Based on what already exists and is likely to exist (and be operational) within this time period, a shortage of conventional reprocessing or, in the future, advanced chemical partitioning capacity is not likely to become a bottleneck.64
- Individual policy decisions to develop indigenous enrichment and conventional reprocessing or, in the future, advanced chemical partitioning capabilities can be viewed on a case-by-case basis and do not have long-term implications. Siting new enrichment facilities or conventional reprocessing or advanced chemical partitioning facilities outside the current locations may send a negative signal, encouraging other states to pursue these technologies. Thus, analyses of potential indigenous fuel cycle facilities, while necessarily constrained by local conditions, must take the global context into account.65
- As a credible long-term interim storage program is developed, the geographic location for final disposal can remain in the exploratory stage, and the schedule for ultimate disposal can be deferred. Because long-term (but interim) storage is a viable technology, there are many credible scenarios for multinational storage as a relatively long-term endeavor (eighty to one hundred years). However, the siting of a long-term interim storage facility is likely to be inextricably linked to the identification of, and “early and positive” dialogue with, stakeholders on a final disposal site (or sites). Therefore, long-term interim storage can be an operative current-term back-end approach, with the full acknowledgment that progress toward establishing a final disposal site (or sites) cannot be deferred indefinitely.
- Evolving a viable multilateral nuclear fuel supplier regime must take into account existing fuel supply arrangements. There are existing relationships among nuclear fuel suppliers and their customers; some of these relationships include conventional reprocessing (possibly, in the future, advanced chemical partitioning) and MOX services. The prospect of rolling back such services is bleak. Furthermore, the existing actors in the current fuel supply regime are likely to be key players in any future fuel cycle regime. Thus, their “buy in” to any proposed evolution of the international fuel supply market will be essential for successful and practical implementation of any such new regime.
ENDNOTES
56.The aqueous fissile streams are designed to include separated fissile plutonium.