CAN THE PROLIFERATION RISKS OF NUCLEAR POWER
BE MADE ACCEPTABLE?
Edwin S. Lyman, PhD
Nuclear Control Institute
Paper presented at the NCI 20th Anniversary Conference,
April 9, 2001, Washington, DC.
The commercial nuclear power industry has generated well over a thousand tonnes of weapons-usable plutonium in spent fuel worldwide, of which more than 250 tonnes have been chemically extracted through reprocessing and more than 150 tonnes remain in storage in separated form. While the proliferation issues associated with the separation, processing and transport of plutonium are widely acknowledged (although their significance remains controversial), the risks associated with the large-scale accumulation of unseparated plutonium has received comparably little attention (except in politically charged circumstances, such as regarding the supply of reactors to Iran). However, when considering the question of whether nuclear power has a role in future energy generation, both aspects must be considered.
There appears to have been a recent resurgence of concern in many quarters about the proliferation risks posed by the nuclear power industry, whether plutonium is separated or not. The notion that viable nuclear energy systems must become more "proliferation-resistant" in the future has practically become gospel in some quarters. The U.S. Department of Energy (DOE) and Russia's Ministry of Atomic Energy (Minatom) have both embraced the concept, with the latter's views apparently receiving the endorsement of the highest levels of the Russian government.
Less enthusiastic about this program are the nations who currently engage in reprocessing, including France, the U.K. and Japan, since any suggestion that nuclear power systems need to become more proliferation-resistant in the future carries the implication that the risks are too high today. Nonetheless, even Director General Mohamed ElBaradei of the International Atomic Energy Agency (IAEA), whose agency is directly responsible for ensuring the effectiveness of the safeguards system in NPT-member states, concedes that "the future of nuclear energy may depend heavily on success in developing new, innovative reactors and fuel cycle designs that exhibit enhanced safety features, proliferation resistance and economic competitiveness." 
The renewed attention to the proliferation risks associated with nuclear power is a welcome development. However, the motivation of some advocates of "proliferation resistance" needs to be more closely examined. In the U.S., nuclear nonproliferation policy is still nominally guided by the Clinton Administration's 1993 statement, which states that "the U.S. does not encourage the civil use of plutonium and, accordingly, does not itself engage in plutonium reprocessing for either nuclear power or nuclear explosive purposes."  This policy has been a perennial source of frustration for plutonium enthusiasts within DOE, who saw one project after another --- such as Argonne National Laboratory's Integral Fast Reactor --- cancelled on this basis.
Clearly, one way of bypassing the letter (although arguably not the spirit) of the policy would be to develop plutonium separation techniques with so-called "proliferation-resistant" features not considered to be "reprocessing" under a strict definition of the term --- that is, without a complete separation of weapons-usable materials from highly radioactive fission products. The same motivation was apparent when former Minatom minister Yevgeny Adamov proposed a moratorium on civil reprocessing at the 1999 IAEA General Conference --- a moratorium which was not intended to apply to the development of a new fleet of plutonium-fueled fast breeder reactors based on a "proliferation-resistant nuclear fuel cycle of natural safety."
The "Technological Opportunities to Increase the Proliferation Resistance of Global Civilian Power Systems" (TOPS) report, issued by a task force of DOE's Nuclear Energy Research Advisory Committee (NERAC), made a not very discriminating recommendation that DOE initiate an expensive new program to pursue analysis, R&D and ultimately demonstration of a wide variety of advanced nuclear power and fuel cycle concepts, including once-through thorium fuels for light-water reactors (LWRs), "dry" (non-aqueous) reprocessing of LWR fuels, liquid-metal fast reactors and spent fuel transmutation technologies. (The TOPS panel apparently never met a reactor system it didn't like.) Accordingly, DOE is establishing the framework for a resurgence of nuclear energy research, through its Nuclear Energy Research Initiative (NERI), Advanced Accelerator Applications (AAA) and Generation IV programs. All these items are targeted for big budget increases in the energy bills now before Congress.
The prospect of a new era of government-subsidized reactor and fuel cycle development, unfettered by the irritating constraints of non-proliferation policy, has led to a virtual feeding frenzy among national laboratories, moribund academic nuclear engineering departments, reactor vendors and other government contractors. DOE's new initiatives have already spawned a number of truly bizarre reactor concepts. Grandiose new "architectures" for nationwide or worldwide nuclear fuel cycles have been proposed. What is missing so far is any interest on the part of electric utilities in these initiatives (with the possible exception of the "pebble-bed modular reactor," which is not a new concept). A reality check is clearly called for here.
To the extent that the notion of proliferation-resistance is intended merely as a moniker designed to put a nonproliferation seal of approval on nuclear fuel cycles based on plutonium recycling, it will be extremely counterproductive. To have a truly proliferation-resistant closed fuel cycle, the risk should be no greater at any point in the process than the risk posed by the once-through cycle --- in other words, the process materials should meet the "spent fuel standard" throughout the process. Achieving this standard will not be a simple task and would likely raise the costs and health risks of the technology to unacceptable levels. However, anything short of this standard will at best provide only a marginal reduction in the risk in exchange for an undoubtedly considerable cost, and at worst will provide a sense of false confidence that will greatly increase the danger in the long-run of diversion or theft of weapons-usable materials.
The Irreducible Proliferation Risk of Nuclear Power
To understand the objectives of the technical fixes that have been proposed for the proliferation risk of nuclear power, it is necessary to understand in more detail the nature of the problem they are trying to solve. As the National Academy of Sciences (NAS) has pointed out in great detail, the concept of proliferation risk is highly dependent on the type of threat under consideration (national, subnational or subnational with the support of a foreign state). Here we will focus, for simplicity, on the subnational threat.
A typical low-enriched uranium (LEU) spent fuel assembly from a pressurized-water reactor contains about 4-5 kg of reactor-grade plutonium --- roughly one bomb's worth --- intimately mixed with about 450 kg of LEU and other radioactive materials. The assembly weighs about 650 kg and is about 3 meters long. While the size, weight and plutonium dilution provide some measure of protection against casual theft of a spent fuel assembly and ready conversion into a component suitable for a weapon, the most important barrier is the "self-protecting" penetrating radiation field. Ten years after discharge from the reactor, this field is typically on the order of 20,000 rem/hr at the surface and 1500 rem/hr at a distance of 1 meter, compared to an acute lethal dose of about 600 rem. This barrier provides a considerable deterrent both to theft of the spent fuel element (without access to a shielded shipping cask and the means to load and transport it), and to recovery of the plutonium (without access to a remote-controlled, heavily shielded industrial plant).
International (IAEA) and domestic (NRC and DOE) standards for physical protection and safeguards of nuclear materials (quite appropriately) regard irradiated and unirradiated materials much differently. Far less stringent requirements apply for irradiated material than for "direct-use" material. For instance, fresh mixed-oxide (MOX) fuel assemblies (each typically containing 20-30 kilograms, or about 3-4 significant quantities, of plutonium) must be inspected once a month, whereas irradiated fuel assemblies (either LEU or MOX) must be inspected once every three to four months. Moreover, the assay protocols are more rigorous for the unirradiated material. With regard to physical protection, irradiation of an item reduces by one grade the "category" and hence the requirements recommended by the IAEA Convention on Physical Protection.
However, an inexorable fact of physics is that the radiation barrier of spent fuel decreases with time. Ten years after reactor discharge, the gamma field is dominated by the isotope Cs-137, which has a half-life of 30 years. Eventually, the radiation barrier will decline to the extent that it can no longer be assumed to provide a reasonable level of self-protection.
How much self-protection is enough? It is impossible to provide an objective numerical value, because any reasonable definition is heavily dependent on the scenario under consideration and a whole host of additional assumptions. Nevertheless, the IAEA has established a lower limit on the dose rate of 100 rem/hr at one meter for defining "irradiated" material for physical protection purposes, a value which is also employed in NRC and DOE requirements. (No comparable value exists for defining "irradiated" material for material accountancy purposes, which is a clear inconsistency.)
A spent fuel assembly with a 1500 rem/hr dose rate at one meter at 10 years after discharge will sink below the 100 rem/hr value after an additional 115 years has elapsed. If the assembly is in above-ground interim storage at that time, consistent application of the rules would dictate that the physical protection requirements for the facility would have to be upgraded. For example, special nuclear material considered "irradiated" under the above standard is exempt from a whole host of NRC physical protection regulations, which would have to be applied once the radiation barrier fell below the threshold. (It is for this reason that DOE is seeking an exemption from the 100 rem/hr limit for its surface spent fuel transfer facility at Yucca Mountain.)
One way to mitigate the risk posed by spent fuel that is no longer self-protecting is to ensure that it is "irretrievably" emplaced in a geologic repository. The additional time and effort that would be required to steal the fuel at that point could be regarded as a "geologic" barrier that could qualitatively replace the missing radiation barrier. At that point, safeguards and physical protection requirements could be comfortably relaxed.
However, the fact remains that a geologic spent fuel repository will contain an enormous amount of weapon-usable plutonium (typically enough for hundreds of thousands of bombs), as well as substantial quantities of other long-lived weapon-usable isotopes, such as neptunium-237. A number of observers have dubbed these facilities "plutonium mines" and argue that because the material in repositories can be accessed using conventional mining techniques, the risk of burying plutonium poses an unacceptably high risk. While those espousing this view primarily employ it in a self-serving way to justify the development of spent fuel transmutation schemes (see below), the issue cannot be discounted entirely.
This question was analyzed by Lyman and Feiveson, who argued that the risk of theft of plutonium from a sealed geologic repository could only be assessed in comparison to the risk that weapon-usable material could be acquired from other sources, such as operating fuel cycle facilities or clandestine production.  They concluded that the attractiveness of plutonium mining would be relatively low, and that repository mining would be easier to detect than other unauthorized activities, such as clandestine reprocessing or uranium enrichment.
Nevertheless, an irreducible risk posed by these plutonium-loaded facilities will remain. Moreover, if it proves impossible to ever site underground facilities because of public opposition, as could well be the case, spent fuel would remain in above-ground storage indefinitely, where the institutional measures that would be essential for providing adequate protection cannot be guaranteed. Hence it must be acknowledged that conventional nuclear power plant operation is creating a massive plutonium inventory that will pose risks far into the future. Before a large-scale revival of nuclear power can be considered, it must be decisively determined whether this risk can be realistically controlled at an acceptable cost and without greatly enhancing near-term environmental, public health and proliferation risks. If the answer is negative, then policymakers should be prepared to concede that nuclear power indeed has no future.
What Does "Proliferation-Resistance" Really Mean? Can it Really Work?
The concepts of "proliferation-resistance" that are being discussed fall into several different categories.  First are those that seek to further increase the proliferation-resistance of the once-through fuel cycle by reducing the quantity and/or "quality" of weapon-usable material in the spent fuel generated, and hence reduce the security burden associated with the storage and disposal of these fuels. These include thorium-uranium fuels, inert matrix (uranium-free) fuels, and ultra-high burnup gas-cooled reactor fuels.
A second category are those that seek to develop processes for plutonium recycle that pose smaller proliferation risks than the PUREX-based reprocessing and mixed-oxide (MOX) fuel fabrication processes that are now employed to varying degrees by France, the United Kingdom, Japan and Russia. These processes would not require complete separation of plutonium from fission products or other actinides, so that the reprocessing product and the recycle fuel would always retain some measure of self-protection.
These two categories are linked in the following way. It is highly unlikely for technical reasons that a once-through system can be developed that would effectively reduce the quantity of weapon-usable material in the spent fuel to a level below concern --- only systems that involve repeated reprocessing and recycling would be able in theory (although not necessarily in practice) to achieve this. However, the near-term proliferation risks associated with the significant additional reprocessing necessary would have to be substantially decreased to justify the desired reduction in long-term risk.
Perhaps an even more important factor is that the intrinsic enhancements in proliferation resistance of closed fuel cycles be credible enough that existing safeguards and security requirements can be reduced with confidence. Safeguards and physical protection are expensive. As members of the IAEAs Safeguards Inspectorate are fond of mentioning, the IAEA safeguards budget has not increased in real terms in more than a decade. It is unclear where the funds would come from to pay for the safeguards effort necessary to support a large-scale expansion of nuclear power, especially for a cycle involving bulk handling of weapon-usable materials. Ultimately, the cost of safeguards should be internalized in the cost of nuclear energy generation. However, no matter who ends up paying for safeguards (the taxpayer or the ratepayer), proliferation-resistant features will not be of any practical benefit unless inspection resources and physical protection costs can be drastically cut. However, it is unlikely that this would be achieved.
There is a great difference in the ease of application of effective safeguards between LEU-based once-through cycles and closed fuel cycles based on reprocessing and recycle. The difficulty of applying effective safeguards increases dramatically as the focus shifts from simple item counting, tags and seals to material accountancy at bulk handling facilities, in which statistical errors and biases in measurement techniques can create large uncertainties that can serve as a cover for material diversion. These uncertainties are already unacceptably large for bulk handling facilities operating today, like reprocessing plants and MOX fuel fabrication plants, even though there are opportunities at some process stages for fairly accurate and precise assays of pure plutonium materials. The dirtier the material, however the less precise and accurate the assays will become. Some argue that this reduction in the capabilities of material accountancy would be tolerable because the diversion threat would be reduced as a result of the reduced accessibility of the materials, so that containment and surveillance would provide adequate assurance against diversion. However, any system will have diversion pathways that can defeat containment and surveillance. There is no substitute for material accountancy.
Both categories of systems described above share a similar vulnerability --- their proliferation-resistant features depend on the systems being operated as designed. The only reliable means of guaranteeing that the systems are not being modified is by direct inspection. This has led to proposals for a third category of systems --- modular, long-lived "nuclear batteries" which are designed never to be opened during their lifetimes. These batteries contain the nuclear fuel and primary system, and could be shipped to balance-of-plant sites all over the world, including nations of proliferation concern, since the opportunities for off-normal operation of the plant would be reduced.
From a non-proliferation point of view, the least objectionable technologies are in the first category. Trying to improve fuel utilization and reduce the weapons attractiveness of spent fuel without the need for reprocessing are reasonable goals. However, one needs to take a hard look at whether the modest benefits of these approaches would be worth the considerable costs of development and deployment.
Reducing the amount of plutonium or other weapon-usable materials in spent fuel sounds like a good idea, especially in view of the issues raised above concerning the long-term plutonium burden of spent fuel accumulation. However, the concepts proposed in this area demonstrate only about a five-fold reduction in plutonium concentration,  whereas a system would have to achieve a much greater reduction --- probably on the order of a factor of 100 --- before it would have a meaningful impact. This is because, for instance, a useful unit for considering the threat of theft is the maximum amount of spent fuel contained in a typical shipment (i.e. to a reprocessing plant, interim storage facility or repository). Current generations of spent fuel shipping casks can carry as much as ten tonnes of spent fuel, and several such casks could be used in a given shipment. A shipment of four casks would contain approximately 100 bombs' worth of plutonium. Therefore, a two order-of-magnitude reduction in the plutonium content of spent fuel would be needed before such a shipment would cease to be attractive to subnational groups seeking a single nuclear device for terrorist purposes.
Also, in the long term, the attractiveness of the plutonium inventory in a Yucca-Mountain-sized repository (on the order of 200,000 weapons) or a large interim storage facility (on the order of 10,000 weapons) would barely be affected by anything short of a 100-fold reduction --- and even that would be inadequate to alleviate the concern.
An even less useful characteristic of these proposed technologies is the reduction in plutonium "quality" that they purportedly could achieve --- that is, an increase in heat- and radiation-emitting plutonium isotopes like Pu-238 and Pu-240. One would hope that this tired old argument would have been retired by now. The fact that plutonium of any isotopic composition is weapon-usable has been well-covered by others at this conference. Perhaps the most striking public statements supporting this were made during a workshop at Lawrence Livermore National Laboratory (LLNL) in June 1999, where Bruce Goodwin, a prominent weapon scientist at LLNL, introduced the concept of explosively fissile materials (EFM) to include "any fissionable material that can be assembled such that an explosive disassembly is possible."  Materials classified as EFM included not only plutonium metal of any isotopic composition, but other isotopes including Am-241 and Np-237, as well as oxides and other compounds containing these isotopes. Concerning the technical challenges associated with using EFM in nuclear weapons, Goodwin stated that "technical challenges can usually be overcome with engineering solutions" and that "experience has shown this to be true in the case of Pu and U." Moreover, he stated that "as nuclear weapon design and engineering expertise combined with sufficient technical capability become more common in the world, it becomes possible to make nuclear weapons out of an increasing number of technically challenging EFMs, many of which are components of spent reactor fuel." This statement leaves little room for doubt that the U.S., and presumably other advanced nuclear states, have overcome the technical challenges necessary for utilizing in nuclear weapons not only plutonium of any isotopic composition, but also other isotopes which present even greater obstacles. How much faith (and funding) are we going to put into the notion that this expertise will not eventually diffuse to other nations and subnational groups by giving credit to nuclear power systems that slightly degrade the isotopics of plutonium in spent fuel? Given Dr. Goodwin's statements, it would not appear to be a safe bet.
The same arguments apply to those recycle systems whose proponents claim are more proliferation-resistant because the do not involve separation of plutonium from other actinides. Apparently, many of those other actinides are weapon-usable as well.
The radiation barriers provided by residual fission products in most of the proposed systems are oversold. For instance, Lyman showed that the radiation barrier of the recycle fuel associated with the Integral Fast Reactor (IFR) cycle --- a system often credited with substantial proliferation resistance --- would be well below the 100 rem/hr criterion at the time of fabrication and would continue to fall off rapidly with time. 
The Problems With Proliferation-Resistant Technologies
The TOPS report asserts that the development of proliferation-resistant technologies could be pursued under terms that are fully compatible with the need to assure that nuclear power continues to adhere to rigorous safety and environmental standards, and moreover that many of the options would appear to be compatible with the objective of assuring that nuclear power is competitive with alternative energy sources.
There may be examples where this indeed may be the case, but they have not yet been identified. In fact, many features designed to enhance proliferation resistance are directly in conflict with the goals of increasing occupational safety, environmental protection and public health protection. In addition, there is absolutely not one shred of evidence that any of the options so far proposed would be economically attractive.
There are numerous safety and environmental issues associated with the proliferation-resistant systems that have been proposed. A short list would include:
Safety of ultra-high burnup fuels and long-lived cores. A trend toward ultra-high burnup fuels can increase the radionuclide source term in the event of a severe accident. Moreover, the materials technology for such fuels is not at hand. Surprises continue to occur for fuels with burnup levels encountered today.
The same concerns apply for long-lived core concepts --- especially those which are not designed to be opened by the recipient country. It is not credible, considering the state-of-the-art in materials science and nuclear technology, that a system could be developed that could be operated safely for a ten- or fifteen-year period without any need to access the core for inspection or in emergency situations. At a recent meeting, one of NRC's regional administrators observed in regard to these proposals that, in his experience, the nuclear plant systems that are most expensive to repair are the ones that weren't intended to be replaced. Unanticipated problems continue to emerge in the nuclear industry, even for systems and materials that are believed to be thoroughly understood. For some of the proposed new systems, which would utilize fuel and coolant materials for which there is little accumulated experience, the occurrence of unpleasant surprises would be a certainty.
There will always be a tension between security and safety goals at nuclear plants. This tension is experienced at nuclear plants today --- in some cases, increasing the security of a plant's vital systems against potential saboteurs requires increasing the delay time for access to certain areas --- exactly the opposite of what would be required to facilitate access for operators in the event of an emergency. Striking the right balance is a challenging task.
"Dirty" reprocessing and recycle: As discussed above, a necessary (but not sufficient) condition for ensuring that a reprocessing and recycle system does not exhibit greater proliferation risk than the once-through cycle is that any weapon-usable material used in the process should never be more accessible that the plutonium in spent fuel --- that is, the "spent fuel standard" should apply throughout the cycle.
This is a standard that is not met by any of the proposed systems. However, the logic of self-protection --- associated with a goal of modifying systems to increase the hazards posed by the process and its associated materials to workers and the public --- is clearly in conflict with basic principles of industrial hygiene and environmental protection. This should clearly give pause to proponents of these systems. Does the world really need widespread deployment of energy systems that are considered to be so threatening that they have to be maintained so as to be as dangerous as possible? At what point should we conclude that this is getting out of hand?
Economic Considerations of Proliferation Resistance
Economic considerations are, of course, also essential. In spite of the TOPS panel's claim that proliferation-resistance can be economically attractive, current trends would appear to work against that view.
There is a clear evolution in electricity generation away from large-capacity baseload plants and toward small capacity, widely distributed modular plants, both in the developed and the developing world. Modular gas turbines are the prime example of this type of system. This has prompted a view among some in the nuclear industry that the future of nuclear power as a competitive source of electricity (and heat) generation lies in its ability to imitate these favorable characteristics of modular gas turbines --- and they may be right.
However, nuclear power may simply not be amenable to this kind of deployment, for both safety and non-proliferation reasons. Reduction in proliferation risk can be most easily achieved through centralization of nuclear facilities and materials in a small number of sites, which would reduce the resources necessary to safeguard and protect them and minimize the number of transport links required. To support a broad deployment of small nuclear plants based on a gas-turbine distribution model would indeed require a highly credible means of reducing the associated proliferation risks, while at the same time not causing unmanageable strains on the safeguards system.
It is not evident that the modular systems that have been proposed meet this test. For instance, one particularly risky concept --- modular, plutonium-fueled, liquid-metal cooled fast reactors with long-lived cores --- clearly are vulnerable to being intercepted during transport. The designer claims that proliferation resistance would be achieved during shipping by embedding the plutonium fuel in solid lead coolant. However, this does not really provide a significant barrier in the event that the entire shipment were hijacked.
The Threat of Radiological Sabotage: A Potential Show-Stopper
Perhaps the greatest obstacle to a greatly expanded deployment of nuclear power plants, especially to regions of political instability, is the threat that the reactor will become a target of radiological sabotage. An armed assault on a nuclear plant's vital safety systems can result in core melt, containment failure and a massive, Chernobyl-like release of radioactive materials into the environment. Radiological sabotage is a prime example of "asymmetric" warfare: the injury and property damage that could be caused by a quantity of high explosives small enough to fit into a backpack could be magnified a thousand-fold if it were strategically applied at a nuclear plant. Such an assault could conceivably fulfill the same goals for a terrorist group as the acquisition and use of a crude nuclear weapon.
Recent experiences in the U.S., which has the world's most rigorous requirements for physical protection at power reactors, have graphically demonstrated the challenges inherent in defending a nuclear plant against sabotage by armed attackers. The Operational Safeguards Response Evaluation (OSRE), a Nuclear Regulatory Commission (NRC) program which uses force-on-force exercises to test the effectiveness of the security at nuclear power plants, has been failed by about 50% of the plants tested, a statistic that has not improved over the course of the program. (An OSRE failure means that the mock attackers would have been able to disable enough plant systems to cause "significant core damage.") This high failure rate occurs even though (as would not be the case in a real terrorist attack) the exercises are scheduled well in advance and nuclear plant security forces undergo significant preparation for them. Moreover, the capabilities of the attacking forces in OSRE exercises are often artificially constrained, and there are questions whether they are an accurate representation of the capabilities of real-world adversaries.
The lesson of the U.S. OSRE program is that significant resources, manpower and training are required to defend nuclear plants against radiological sabotage. The costs of maintaining the security programs necessary to pass an OSRE are considered burdensome by U.S. nuclear plant operators, who have been actively seeking reductions in physical protection requirements. It is highly doubtful that providing adequate physical protection for a system of widely distributed nuclear plants, some of which may be close to urban areas, will be affordable. A large part of the economic argument for modular reactors is the ability to reduce plant staffing significantly --- however, the security force requirements would likely provide a floor on reductions that would be too high. Even nuclear plants that are fully proliferation-resistant will remain vulnerable to sabotage, and even the safest designs will have weak links that could be exploited. Sabotage of shipments of nuclear materials also poses a threat that is currently underplayed but clearly would need to be assessed.
The risk of radiological sabotage is of particular concern for politically unstable regions in the developing world, which are among those targeted as the most likely customers for small, modular nuclear plants. For instance, Indonesia has shown a great deal of interest in the gas-cooled pebble-bed modular reactor, and in 1999 presented a study where it surveyed the entire archipelago --- from Aceh to Irian Jaya --- for candidate sites for reactor placement.  Considering the level of ethnic violence and corruption in the country, legitimate questions can be asked about whether security forces could be located that could be trusted with guarding a large number of plants in these densely populated islands.
Accelerator Transmutation of Waste: A Totalitarian Scenario
Returning to the issue of the irreducible proliferation risk of nuclear power, one can ask if there is any hope for a technical solution to the nuclear waste and plutonium accumulation problem that will free nuclear power from the nagging environmental and proliferation issues that plague it. With geologic repository development on a slow track all around the world, some researchers have stepped into the breach with proposals for ambitious spent fuel "transmutation" schemes --- elaborate systems, either reactor- or accelerator-based, that promise to rid the nuclear fuel cycle of all long-lived radioactive wastes, including plutonium and other weapon-usable actinides. 
One of the more prominent proposals, arising from the Los Alamos National Laboratory (LANL), is known as Accelerator Transmutation of Waste (ATW). Backed by the powerful U.S. Senator Pete Domenici of New Mexico, a staunch supporter of LANL, and also supported by Congressional opponents of the Yucca Mountain repository, DOE funds have been provided in recent years for ATW studies.
In 1999, DOE issued a report to Congress entitled "A Roadmap for Developing ATW Technology." The report describes how a massive nationwide system of spent fuel reprocessing plants, accelerator-driven spallation neutron sources, liquid-metal cooled ATW target assemblies and pyrochemical ATW reprocessing plants --- a prime example of what some have referred to as a new fuel cycle "architecture"  --- could transmute the entire U.S. spent fuel inventory over a 118-year period for a cost of only $279 billion (1999 dollars).
It may well be true that such an "architecture" is the only way in which the plutonium accumulation problem can be managed (in theory). However, what the ATW Roadmap doesn't address is who is going to pay to design, build and run these facilities for over a century --- not to mention protect and safeguard all the nuclear material processing and transport --- with the degree of rigorous coordination that would be essential if the endeavor were to have the slightest chance of success. For one of the basic facts of transmutation is that if the system were to fail before the job were complete, the actual reduction in plutonium and other wastes that would have been achieved would be less than an order of magnitude, and the project would be nothing more than a big waste of money and time.
There is only one answer to the question in the previous paragraph: the government. Looking at the chaos plaguing the electricity industry today, it is very difficult to imagine that it would ever be able to act as one coordinated unit unless it were nationalized. As the Roadmap itself concedes, "it is unlikely that the private sector would implement a waste transmutation scheme on its own without incentives ... the federal government would have to play the primary role in organization, management and funding of any such system." 
Such an eventuality is not impossible. If society decides that ridding the country of plutonium and other long-lived nuclear wastes is a public good that is worthy of massive taxpayer support, then a government takeover of electric utilities for this purpose may be justifiable. However, the public --- not to mention the conservative members of Congress who are staunch supporters of the program --- must be made aware that this is what it would take to solve the problem, and should be fully informed of the costs and risks involved. If neither the public nor the private sector decides that it is willing to subsidize such an effort, then the nuclear industry must be willing to accept the fact that its continued operation is unsustainable.
 Mohamed ElBaradei, Statement to the Forty-fourth Regular Session of the IAEA General Conference, September 2000, Vienna.
 White House Fact Sheet, "Nonproliferation and Export Control Policy Statement," September 27, 1993.
 E. Lyman and H. Feiveson, "The Proliferation Risks of Plutonium Mines," Science and Global Security 7 (1998) 119.
 Feiveson has done a thorough analysis of these different categories and the technologies intended to address each one (H. Feiveson, "Diversion-Resistance Criteria for Future Nuclear Power," Workshop on "Does Nuclear Power Have a Role in Climate Mitigation?", Stanford University, June 22-23, 2000).
 See, for example, J. Herring and P. MacDonald, Idaho National Engineering and Environmental Laboratory, "Low-Cost, Proliferation-Resistant, Uranium-Thorium Dioxide Fuels for Light-Water Reactors," presented at the Workshop on Proliferation-Resistant Nuclear Power Systems, Lawrence Livermore National Laboratory, June 2-4, 1999.
 Summary of the Workshop on Proliferation-Resistant Nuclear Power Systems, UCRL-JC-137954, Center for Global Security Research, Lawrence Livermore National Laboratory, June 2-4, 1999, p. 14.
 E. Lyman, "Interim Storage Matrices for Excess Plutonium: Approaching the `Spent Fuel Standard' Without the Use of Reactors," PU/CEES Report No. 286, Center for Energy and Environmental Studies, Princeton University, August 1994.
 A. Rusli and B. Arbie, National Atomic Energy Agency for Indonesia, "Identification Of Domestic Needs Of Modular Heater For Electric And Heat Process Industry In Indonesia," The First Information Exchange Meeting on Survey on Basic Studies in the Field of High Temperature Engineering, Nuclear Energy Agency, Paris, 27-29 September 1999.
 For a comprehensive critique of various transmutation schemes, see H. Zerriffi and A. Makhijani, "The Nuclear Alchemy Gamble," Institute for Energy and Environmental Research, Takoma Park, Md, August 25, 2000.
 R. Wagner, E. Arthur and P. Cunningham, "Plutonium, Nuclear Power and Nuclear Weapons," Perspectives on Science and Technology, Summer 1999.
 U.S. Department of Energy, "A Roadmap for Developing Accelerator Transmutation of Waste Technology," DOE/RW-0519, October 1999, 4.2.