United States and other
countries around the world looking to nuclear power for their energy needs must
consider how spent fuel will be handled as they construct new plants and
examine existing ones, especially in light of the recent crisis in Japan, according
to a comprehensive study from MIT.
ongoing problems at Japan’s
Fukushima Daiichi powerplant—caused by the March 11 earthquake and tsunami—have
been significantly exacerbated by the presence of used fuel housed in the
reactor buildings, and demonstrate the urgency needed in dealing with such
waste, the report’s authors say. It specifically underscores the importance of
finding a way to deal with the growing amount of spent nuclear fuel housed at
report, a summary of which was released last September, strongly recommends that an
interim solution be developed to remove spent fuel from storage facilities at
reactor sites, and move it to regional, medium-term repositories where the fuel
can be monitored and protected as it decays over time. Spent fuel loses much of
its radioactivity with every passing decade, as the most dangerous radioactive
isotopes decay and lose much of their potency during the first 50 years, thus
diminishing the problem of long-term storage.
for the ultimate handling of spent nuclear fuel “has frankly been an
afterthought in U.S.
fuel-cycle policy,” said Ernest J. Moniz, director of the MIT Energy Initiative
(MITEI) and co-chairman of the new report, at a press conference today to
introduce the report. “It can’t be that,” he said. Instead, “it should be
integrated” into the overall planning for the nation’s energy policies and “the
should move toward centralized spent nuclear fuel storage.”
the situation in Japan has not changed any of the basic conclusions of the
study, called “The Future of the Nuclear Fuel Cycle,” the study’s
executive director Charles Forsberg, a research scientist in MIT’s Department
of Nuclear Science and Engineering, said the recent crisis “will place more
emphasis on getting a geological repository program up and running” for
permanent storage of the United
States’ spent nuclear fuel. Doing so, the
study says, faces no real scientific hurdles, and is essentially a social and political
issue at this point.
before the problems in Japan,
Moniz said, there had been “increased interest in Congress, among the chairs of
relevant committees” on looking at options for interim spent fuel storage. In
response to a question, Moniz said that the right time for the United States
to start looking seriously into how to set up regional interim storage
facilities “was a few years ago.”
Consequences of Japan’s
But there are other possible impacts on the global future of nuclear power in
the aftermath of the Japanese crisis, where four reactors at the Fukushima plant were
crippled and work continues to bring the situation fully under control. In a
postscript to the report’s introduction, the authors point out two other likely
consequences, at least in the short run: The cost of new nuclear plants is
likely to increase, as a result of the increased perception of risk associated
with such plants, which will raise the cost of capital for plant construction;
and public support for a resurgence of nuclear power, which had been growing in
the United States, is likely to suffer at least a temporary setback. Already,
several countries have suspended or delayed plans for new nuclear plants or for
extending the operating lifetime of existing plants.
important factor that might help counter the erosion of public support for a
renewal of nuclear power as a result of the Japanese crisis is to put clear
policies in place now for dealing with the spent fuel, Moniz said. “Solving the
nuclear waste problem does influence public attitudes,” he said.
of repeated delays in creating a national long-term storage repository for
spent nuclear fuel (SNF), U.S.
nuclear reactor sites already house more spent fuel than those in Japan, Forsberg
noted. That confirms the study’s existing conclusions about the need for a
policy on spent fuel, to replace the present ad-hoc policy.
Japanese crisis “will place a greater emphasis on our recommendation for
centralized storage or disposal in a repository with the option of SNF
recovery,” Forsberg said, referring to the report’s suggestion that used fuel
be stored in such a way that it could easily be recovered later if the nation
decides to pursue a nuclear program based on reprocessing it to produce new
fuel for a future generation of reactors.
full 253-page interdisciplinary study was produced under the auspices of MITEI
and co-chaired by Moniz, the Cecil and Ida Green Distinguished Professor of
Physics and Engineering Systems, and TEPCO Professor of Nuclear Engineering
Mujid Kazimi, who also is director of the Center for Advanced Nuclear Energy
latest in a series of broad-based MITEI studies of different aspects of energy,
this report was produced by 10 faculty members, three contributing authors and
eight student research assistants, with guidance from a 13-member expert
advisory panel comprising members from industry, academia and nonprofit
organizations; it took about two years to produce.
Improving efficiency through design
The study suggests that nuclear power can play a significant part in displacing
carbon-emitting fossil-fuel plants, and thus help to reduce the potential for
global climate change. About half of existing nuclear powerplants around the
world—and all of those in the United States—use a once-through fuel cycle, in
which fuel rods are sent to a disposal site after a single use in the reactor,
rather than being reprocessed for future use. But to decide on the best kind of
fuel cycle for the anticipated next generation of nuclear powerplants—whether
it should continue to be a once-through system, or one using partial or full
reprocessing for a “closed-loop” system—will require more research, the report
long as demand for new nuclear plants continues at rates similar to those
experienced so far, there is no danger of running out of uranium in the next
several decades, the report concludes. But, Kazimi said, “If demand starts to
grow more rapidly, we will need more efficient fuel cycles.”
promising possibility, the study suggests, is an enriched uranium-initiated
breeder reactor in which fissile materials bred inside the reactor are
recycled, and additional uranium is added to the reactor core at the same rate
that nuclear materials are consumed. In such a system, no excess nuclear
materials are produced, leading to a simple and efficient self-sustaining fuel
cycle. However, there is little hard data on whether such a cycle would be
practical and economically competitive. One of the report’s major conclusions
is that more research is needed before such decisions can be made.
has been much interest in recent years in advanced reactor designs such as
small, self-contained modular reactors or ones that use passive cooling systems
that reduce or eliminate the need to keep water circulating. As Moniz said, “Moving to any of these smaller reactors does not change the choice of fuel
cycle,” and so was outside the scope of this study. But Andrew Kadak SM ’70,
PhD ’72, a member of the study panel and former MIT Professor of the Practice
of Nuclear Energy, said that so far “the industry has not taken this
[possibility of small modular plants] seriously,” pointing out that none have
been ordered so far.
A holistic approach
One key message of the report is that it’s time to really study the underlying
basis of nuclear-plant technology—what kind of fuel goes in, what comes out,
and what happens to it then—before focusing too much money and effort on the
engineering details of specific powerplant designs.
report also supports the current U.S. policy of providing loan
guarantees for the first several new nuclear plants to be built after the
current three-decade hiatus, in order to reduce the risks of new construction
and thus reduce or eliminate financing premiums for nuclear plant construction.
study, unlike most earlier examinations of possible future nuclear plants,
looked comprehensively at all the various components—from mining to reactor
operation all the way through to waste disposal—in a holistic way. It was
funded by the Electric Power Research Institute, Idaho National Laboratory,
Nuclear Energy Institute, Areva, GE-Hitachi, Westinghouse, Energy Solutions,
and NAC International.