Frank N. von Hippel
At the end of November, the US National Academies posted a report in response to a request from Congress to "examine the merits and viability of different nuclear fuel cycle options, waste aspects of advanced reactors and their fuel cycles, and nonproliferation and security risks of these technologies." The US Department of Energy (DOE) has been promoting spent fuel reprocessing as a way to dispose of accumulating spent fuel and exotic types of helium, molten sodium and molten-salt-cooled "small modular reactors" as an alternative to the new large water-cooled conventional power reactors that have become too costly to be economically competitive in the United States and most other countries.
With regard to the proliferation dangers of reprocessing, the study panel acknowledged the obvious:
...Fuel cycles involving reprocessing and separation of fissile material [such as plutonium] that could be weapons usable pose greater proliferation and terrorism risks than the [current] once-through uranium fuel cycle with direct disposal of spent fuel... - Finding 20
The panel also expressed concern that many of the small modular demonstration reactor types DOE's Office of Nuclear Energy has been co-funding are to be fueled with "high-assay low-enriched uranium" (HALEU) enriched to between 10 and 20 percent U-235. Current-generation power reactors are fueled with uranium enriched to less than five percent,
Expanding the global use of high-assay low-enriched uranium (HALEU) would potentially exacerbate proliferation and security risks because of the potentially greater attractiveness of this material for nuclear weapons compared with the low-enriched uranium used in light water reactors. The increased number of sites using and states producing this material could provide more opportunity for diversion by state or nonstate actors. - Finding 19
The panel went on to critique the claimed benefits of spent fuel reprocessing that are being using to justify reprocessing to manage the country's accumulating spent fuel. (In October, the DOE gave out another dozen grants to universities, private companies, and its national laboratories to develop new ways to separate plutonium and other transuranic elements from spent fuel.)
The committee found no benefits but many potential costs. These are the same conclusions arrived at by a 1996 National Academies report on the management of US spent fuel. That report was commissioned by DOE but has been ignored by the offices within DOE responsible for funding nuclear energy research, development, and demonstration (the Office of Nuclear Energy and the Advanced research Projects Agency-Energy [ARPA-E]).
The Executive Summary of the new report states,
the introduction and use of advanced reactors will do little, if anything, to mitigate the need for successful management and disposal of nuclear waste.
Instead, the panel urged Congress to get on with the task of creating an organization responsible for finding a deep repository for US spent fuel. That responsibility was undertaken by the federal government forty years ago in the 1982 Nuclear Waste Policy Act. DOE's effort to implement that commitment collapsed after Congress picked Yucca Mountain in Nevada as the site for the national repository and Nevada fought DOE to a halt.
Congress will need to establish a single-mission entity with responsibility for managing and disposing of commercial nuclear waste. The entity will need continuity of leadership and funding, as well as a consistent disposal strategy; it will also need high technical and scientific competence, and the ability to organize and lead research programs and large construction projects. Importantly, such an entity will need to engage the public in a way that engenders trust. Finally, the entity will need to operate effectively over the many decades that will be required to manage the present inventory of nuclear waste, as well as waste generated by future advanced reactors (emphasis added).
The panel also found that advocates of separating and fissioning the plutonium in spent fuel have been misleading Congress and the public about the hazard-reduction benefits,
Radiological risks from disposed waste are dominated by the mobility of long-lived radionuclides and not by the radiotoxicity inventory...The long-term safety of disposal of actinides [plutonium and other transuranic elements] in appropriate geologic settings is largely independent of the actinide inventory of the repository, except in the off-normal situation where the geological barrier is bypassed--for instance, by human intrusion. - Finding 13
The panel implicitly criticized the indiscriminate way in which Congress and DOE's Office of Nuclear Energy have been supporting proposals for nuclear energy research, development, and demonstration.
Congress and DOE will benefit from obtaining an independent assessment of cost estimates of various scenarios for potential deployment of advanced reactor technologies and related fuel cycle components... - Executive Summary
It stated furthermore that disposal of the radioactive waste from the exotic reactors DOE's Office of Nuclear Energy is currently promoting could be much more complex than disposal of the spent fuel from today's water-cooled reactors (LWRs).
Sodium-cooled fast-[neutron] reactors would produce large volumes of irradiated sodium waste that would require treatment and disposal... Molten salt reactors produce two waste streams, radioactive off-gases and the spent fuel salt waste, that would require processing into waste forms suitable for disposal. These treatment methods and suitable wastes forms are in early stages of exploration. Most of these advanced reactors would produce large quantities of irradiated graphite waste--from use as moderators or reflectors--and this material would prove challenging to manage as well. - Finding 15
The panel warned specifically about the potentially huge down-stream costs of the programs whose exploration DOE is funding.
The costs of advanced reactors and their associated fuel cycles could range from at least several billion dollars--for pilot-scale non-light water advanced reactors and their fuel cycle facilities--to hundreds of billions of dollars--for full deployment of an alternative fuel cycle that would replace the existing once-through cycle and existing light water reactors. Congress and the U.S. Department of Energy will need better understanding of the cost estimates for various scenarios of reactor deployment and supporting fuel cycle requirements to aid their decision making as to what technologies to support in the coming years. - Finding 10
Because of its broad spectrum of views, however, the committee could not agree on the obvious implications of its assessment. Its compromise was to back more research in areas where no more research is needed.
The once-through fuel cycle is the baseline, and any new fuel cycles should have advantages over that baseline for them to be deployed. However, so as not to preclude these options in the future, the U.S. Department of Energy (DOE) should continue fundamental studies to evaluate the feasibility of using recycling and transmutation for closing fuel cycles. Specifically, DOE should develop and implement a phased, long-range research and development program that focuses on advanced separations and transmutations technologies. - Recommendation D
It would be worth Congress asking, however: If, after 50 years of research and development on alternative nuclear fuel cycles, no alternative has been identified that is less costly and more proliferation resistant than the current once-through fuel cycle, why should DOE fund more research and development on "advanced" reprocessing technologies?
Worldwide promotion of spent fuel reprocessing R&D by DOE's predecessor agency, the US Atomic Energy Commission, produced India's and (in reaction) Pakistan's nuclear-weapons programs. If the State Department under Henry Kissinger had not intervened quickly and forcefully after India's first nuclear test in 1974, Brazil, South Korea, and Taiwan probably all would have followed India's path to nuclear weapons. All had military governments at the time, and all had ordered reprocessing equipment from vendors in France and Germany.
It also is worth remembering the warning from Theodore B. Taylor, a legendary nuclear-weapons designer who went public in the 1970s with his conclusion that the technology of detonators and plastic explosives had advanced to the point where, if terrorists had access to separated plutonium, they might be able to make nuclear explosives. Taylor was terrified by the Atomic Energy Commission's vision of a world powered by millions of weapon-equivalents of plutonium being separated, fabricated, and shipped annually in the commercial nuclear power plant fuel cycle.