Nuclear Science: Developing Technology to Reduce Radioactive Waste May
Take Decades and Be Costly (Chapter Report, 12/10/93, GAO/RCED-94-16).
U.S. efforts to develop a technology, known as waste transmutation, that
might be able to reduce the volume and the radioactivity of nuclear
waste have lagged because the Energy Department (DOE) believes that the
technology is too costly and unnecessary. Such radioactive waste, the
legacy of commercial nuclear power and nuclear weapons production, will
have to be buried in a deep geological repository. In essence, any
practical application of transmutation is at least decades away, and
several roadblocks would likely slow or prevent application should it be
pursued. These include current funding constraints; the high cost and
the long time needed to develop and implement transmutation; and the
technical, institutional, and public challenges that would need to be
overcome. Moreover, DOE's waste managers, industry representatives, and
others now believe that transmutation is neither necessary nor
cost-beneficial.
--------------------------- Indexing Terms -----------------------------
REPORTNUM: RCED-94-16
TITLE: Nuclear Science: Developing Technology to Reduce
Radioactive Waste May Take Decades and Be Costly
DATE: 12/10/93
SUBJECT: Nuclear waste disposal
Nuclear waste storage
Nuclear waste management
Radioactive wastes
Research and development
Energy research
Research and development costs
Cost control
Cost analysis
Nuclear facilities
IDENTIFIER: DOE Advanced Liquid Metal Reactor/Integral Fast Reactor
Program
DOE Accelerator Transmutation of Waste Program
DOE Phoenix Accelerator Program
DOE Particle-Bed Reactor Program
DOE Clean Use of Reactor Energy Program
**************************************************************************
* This file contains an ASCII representation of the text of a GAO *
* report. Delineations within the text indicating chapter titles, *
* headings, and bullets are preserved. Major divisions and subdivisions *
* of the text, such as Chapters, Sections, and Appendixes, are *
* identified by double and single lines. The numbers on the right end *
* of these lines indicate the position of each of the subsections in the *
* document outline. These numbers do NOT correspond with the page *
* numbers of the printed product. *
* *
* No attempt has been made to display graphic images, although figure *
* captions are reproduced. Tables are included, but may not resemble *
* those in the printed version. *
* *
* A printed copy of this report may be obtained from the GAO Document *
* Distribution Facility by calling (202) 512-6000, by faxing your *
* request to (301) 258-4066, or by writing to P.O. Box 6015, *
* Gaithersburg, MD 20884-6015. We are unable to accept electronic orders *
* for printed documents at this time. *
**************************************************************************
Cover
================================================================ COVER
Report to the Chairman, Subcommittee on Energy, Committee on Science,
Space, and Technology, House of Representatives
December 1993
NUCLEAR SCIENCE - DEVELOPING
TECHNOLOGY TO REDUCE RADIOACTIVE
WASTE MAY TAKE DECADES AND BE
COSTLY
GAO/RCED-94-16
Transmutation of Radioactive Waste
Abbreviations
=============================================================== ABBREV
ALMR - Advanced Liquid-Metal Reactor
ATW - Accelerator Transmutation of Waste
BNL - Brookhaven National Laboratory
CURE - Clean Use of Reactor Energy
DOE - Department of Energy
EPRI - Electric Power Research Institute
GAO - General Accounting Office
HLW - high-level waste
IFR - Integral Fast Reactor
LANL - Los Alamos National Laboratory
LLW - low-level waste
LWR - light-water reactor
PBR - Particle-Bed Reactor
PUREX - plutonium-uranium extraction
TRU - transuranics
TRUEX - transuranic extraction
Letter
=============================================================== LETTER
B-254881
December 10, 1993
The Honorable Marilyn Lloyd
Chairman, Subcommittee on Energy
Committee on Science, Space,
and Technology
House of Representatives
Dear Madam Chairman:
As you requested, this report presents the status of U.S. efforts to
develop a technology (called waste transmutation) that might be able
to reduce the volume and radioactivity of nuclear waste that would
have to be buried in a deep geological repository. The possible
implementation of waste transmutation is decades away and faces a
number of challenges that may prevent its practical application to
the existing radioactive waste problem. In addition to the report,
we are forwarding to you supplemental material containing technical
descriptions and analyses of the transmutation concepts described in
this report.
As arranged with your office, unless you publicly announce its
contents earlier, we will make no further distribution of this report
until 30 days after the date of this letter. At that time, we will
send copies to the Secretary of Energy and the Director, Office of
Management and Budget. We will also make copies available to others
on request.
This work was performed under the direction of Victor S. Rezendes,
Director of Energy and Science Issues, who can be reached on (202)
512-3841, if you or your staff have any questions. Other major
contributors to this report are listed in appendix I.
Sincerely yours,
J. Dexter Peach
Assistant Comptroller General
EXECUTIVE SUMMARY
============================================================ Chapter 0
PURPOSE
---------------------------------------------------------- Chapter 0:1
Radioactive waste is a major negative legacy of commercial nuclear
power and the production of nuclear weapons. The difficulty of
adequately disposing of this long-lived radioactive waste and the
public's perception of its dangers are among the reasons why the
nuclear industry has stopped growing. Current national policy calls
for disposal of high-level radioactive waste related to nuclear
weapons production and spent (used) fuel from commercial nuclear
reactors in a deep geological repository. Some scientists believe,
however, that the Department of Energy (DOE) should attempt to
transmute (change) this waste into a less radioactive form before
burying it. Transmutation might result in certain benefits, such as
reducing the volume and radioactive life of some of the waste to be
buried.
Concerned about the nuclear waste problem in the United States, the
Chairman of the Subcommittee on Energy, House Committee on Science,
Space, and Technology, asked GAO to determine the status of U.S.
research to transmute radioactive waste. Specifically, GAO was asked
to (1) identify U.S. efforts to develop waste transmutation
technology, (2) determine the estimated timing and cost of this
development, and (3) assess the prospects for practical application
of transmutation to highly radioactive defense waste and to spent
fuel from existing commercial reactors.
BACKGROUND
---------------------------------------------------------- Chapter 0:2
DOE is responsible for the final disposal of both spent fuel and
highly radioactive defense waste. Commercial power plant operators
currently store most spent fuel in pools of water near the reactor.
DOE stores defense-related radioactive waste primarily in underground
tanks. When a repository becomes available, current national policy
calls for DOE to transfer the spent fuel and defense waste to that
repository for permanent disposal. DOE plans to open a deep
geological repository in 2010.
Spent fuel contains a relatively small number of long-lived
radioactive elements that are responsible for the long period that
this waste is required to be confined in a repository. If DOE could
transmute these elements to stable ones or ones with shorter
radioactive life spans, it might reduce the long-lived hazards of the
waste and increase the capacity of the repository. DOE could use a
reactor's or an accelerator's nuclear reactions to transmute these
long-lived elements. However, DOE would have to first reprocess the
spent fuel to separate the long-lived elements and then incorporate
them into new fuel (or a target for an accelerator to bombard). The
fuel would be burned, reprocessed, refabricated, and burned again in
a continuous cycle. Although the transmutation process might
eventually produce a waste that has a much shorter radioactive life,
residual high-level wastes and radioactive elements that cannot be
transmuted would still need to be buried in a repository.
Although transmutation could be considered for treating
defense-related nuclear waste, current plans call for DOE to separate
the waste into high- and low-level components and dispose of the
high-level component in a deep geological repository.
RESULTS IN BRIEF
---------------------------------------------------------- Chapter 0:3
DOE's radioactive waste managers are not pursuing the transmutation
of waste because they believe that it is too costly and unnecessary.
However, some of DOE's national laboratories and DOE's Office of
Nuclear Energy have developed concepts to use advanced reactors or
accelerators to transmute radioactive waste, but the research
necessary to prove that these concepts are technically and
economically feasible has not been done. The concepts have
concentrated on the transmutation of spent fuel because most
proponents of the concepts consider that the much larger and
increasing volume of commercial spent fuel makes it a more likely
candidate for transmutation than existing defense waste. DOE has
asked the National Research Council to review these concepts and
report its findings to DOE by July 1994.
Preliminary, incomplete estimates from proponents of waste
transmutation show that it could cost many billions of dollars to
develop and field the first spent fuel processing and transmutation
system. According to data supplied by the proponents, this first
system, driven by a reactor or an accelerator, could begin commercial
operation by about 2015. However, according to most of the
proponents, additional systems would be required to treat the
inventory of spent fuel, and treatment would cost additional tens of
billions of dollars and take decades or more to complete. Some of
the transmutation costs might be recouped by generating and selling
electricity.
In essence, any practical application of transmutation is at least
decades away, and a number of constraints would slow or prevent
application should it be actively pursued. These include current
funding constraints; the high cost and long time needed to develop
and implement transmutation; and the technical, institutional, and
public challenges that would need to be overcome. Moreover, DOE's
waste managers, industry representatives, and others currently
believe that transmutation is not necessary or cost-beneficial.
PRINCIPAL FINDINGS
---------------------------------------------------------- Chapter 0:4
TECHNICAL AND ECONOMIC
FEASIBILITY OF WASTE
TRANSMUTATION IS UNPROVEN
-------------------------------------------------------- Chapter 0:4.1
DOE managers who are responsible for the disposal of radioactive
defense waste and commercial spent fuel are not in favor of
transmuting waste before it is buried in a repository. They believe
it unnecessary and costly and note that a repository will still be
needed, even if transmutation of some of this waste is successful.
Some of DOE's national laboratories and DOE's Office of Nuclear
Energy, however, have identified concepts for the transmutation of
radioactive waste. The proposed concepts involve reactor- or
accelerator-driven systems: the Advanced Liquid-Metal
Reactor/Integral Fast Reactor (ALMR/IFR) program sponsored by the
Office of Nuclear Energy and involving the General Electric Company
and the Argonne National Laboratory; the Accelerator Transmutation of
Waste program at the Los Alamos National Laboratory; the Phoenix
accelerator program and the Particle-Bed Reactor program at the
Brookhaven National Laboratory; and the Clean Use of Reactor Energy
program at the Hanford Reservation.
With the exception of the ALMR/IFR, all of the transmutation concepts
are based on theoretical studies. The ALMR/IFR transmutation concept
is further along because it has been funded as part of the DOE Office
of Nuclear Energy's program to develop a liquid-metal breeder
reactor. The other concepts have received no direct DOE funding, but
proponents claim advantages over the ALMR/IFR. None of the concepts,
including the ALMR/IFR, has been proved to be technically or
economically feasible. ALMR/IFR program officials hope to provide
partial proof of the technology's feasibility by 1998.
Although DOE has shown little active interest in most of the
transmutation concepts, it has asked the National Research Council to
study the benefits and costs of different transmutation concepts and
report its findings by July 1994.
TRANSMUTING EXISTING WASTE
IS EXPECTED TO BE COSTLY
-------------------------------------------------------- Chapter 0:4.2
Although U.S. research on radioactive waste transmutation is not far
enough along to develop accurate cost and schedule estimates,
proponents have provided preliminary estimates. While the estimates
are incomplete, they provide a sense of the relative cost of and
schedule for transmuting existing spent fuel waste.
Analysis of data supplied by proponents shows that they could develop
and field their first transmutation system and start commercial
operations by about 2015. (Demonstrations of the component systems
would occur a few years earlier.) A complete system would include a
reactor or accelerator to transmute reprocessed spent fuel, a spent
fuel reprocessing and waste separation facility, a fuel refabrication
facility, and storage facilities for the spent fuel (prior to
processing) and residual wastes from the fuel reprocessing and
transmutation. In addition, some concepts propose building a power
plant to generate and sell electricity to help offset the costs of
transmutation. Proponents estimate that it may cost several billion
dollars to develop and construct a reactor or accelerator that would
be able to transmute reprocessed spent fuel from existing reactors.
Additional billions would be needed for a fuel reprocessing and
refabrication facility, storage facilities, and a power plant.
After the first system is fielded, most proponents estimate that many
more--perhaps about 20 or more--might be needed to treat existing
spent fuel that will have accumulated by 2030, when the current
generation of reactors will have been retired or replaced. Analysis
of proponents' data shows that this effort would cost additional tens
of billions of dollars and take decades to as many as 200 years,
depending on the transmutation concept.
ANY PRACTICAL APPLICATION OF
TRANSMUTATION IS DECADES
AWAY
-------------------------------------------------------- Chapter 0:4.3
DOE may find it impractical to develop transmutation technology
primarily to treat existing waste because of a number of problems and
circumstances, including high costs, possibly modest benefits, and
technical and institutional challenges.
Any transmutation research and development is likely to be stretched
out over many decades because of a lack of interest and funding to
aggressively pursue it. Those who have transmutation concepts to
sell are enthusiastic. However, DOE's nuclear waste disposal
managers, representatives from the power industry, and some who have
studied transmutation believe that it is not necessary or
cost-beneficial to transmute existing waste. They emphasize that
even if DOE is able to transmute the waste, a repository will still
be needed. In addition, the current national policy calling for
direct disposal of commercial spent fuel would have to be changed to
allow fuel reprocessing and transmutation before burial.
Critics of proposals to transmute waste also note that none of the
proposed transmutation concepts has been proved to be technically or
economically feasible. Furthermore, they emphasize that DOE would
have to research and develop efficient and economic methods for
reprocessing and separating the waste before transmutation can occur.
In addition, DOE would have to overcome other challenges, including
licensing requirements and public acceptance, before it could field a
transmutation system.
On the other hand, many critics and proponents of transmuting
existing waste seem to agree that, if transmutation could be proven
to be technically and economically feasible, it might be an
attractive design feature for future power plants, if U.S. demand
for nuclear power continues and increases in the next century.
RECOMMENDATIONS
---------------------------------------------------------- Chapter 0:5
GAO makes no recommendations in this report.
AGENCY COMMENTS
---------------------------------------------------------- Chapter 0:6
As requested, GAO did not obtain written agency comments. However,
GAO did discuss the contents of this report with DOE's Acting
Director of the Office of Strategic Planning and International
Programs, Civilian Radioactive Waste Management; DOE's Associate
Deputy Assistant Secretary, Office of Technology Development,
Environmental Restoration and Waste Management; DOE's Director of the
Office of Nuclear Energy; and the National Research Council's project
director for the transmutation portion of its ongoing study. GAO
incorporated their views, where appropriate.
DOE's waste disposal managers and representatives of the National
Research Council agreed with the report's conclusions. The Director
of DOE's Office of Nuclear Energy said that it was too early to make
accurate estimates of the cost of transmutation and was concerned
that conclusions about the potential cost of transmutation may
discourage support for further research involving the ALMR/IFR
system. The cost and schedule estimates used in this report are
based on information supplied by the transmutation concept
developers. In addition, most of the concept developers (excluding
those in the Particle-Bed Reactor program) reviewed GAO's analyses
and presentation of this information. The cost and schedule
estimates are preliminary and incomplete, but they do provide a sense
of the potential magnitude of implementing a U.S. program to
transmute radioactive waste.
INTRODUCTION
============================================================ Chapter 1
Commercial nuclear power plants produce spent (used) nuclear fuel as
a radioactive waste product when they burn nuclear fuel to generate
electricity. The production of nuclear weapons has also produced
spent fuel, most of which has been reprocessed to reclaim the uranium
and plutonium contained in it. This reprocessing of the defense fuel
has generated liquid and solid wastes classified as high-level
radioactive waste.\1 Spent nuclear fuel and high-level waste are very
radioactive and must be isolated from the environment for thousands
of years. Nuclear power plants and weapons' facilities have
generated tens of thousands of tons of these wastes since the 1940s.
However, the Department of Energy (DOE) has not developed a permanent
disposal method or site for these wastes. Currently, commercial
nuclear power plant operators store spent fuel on site near their
reactors. Defense-related nuclear waste is primarily stored in
underground tanks or bins. The Congress addressed the disposal
problem in the Nuclear Waste Policy Act of 1982 (P.L. 97-425), as
amended in 1987, which requires DOE to develop a repository for
permanent disposal of spent fuel and high-level radioactive waste.
Current national policy, reiterated in September 1993 by the
Secretary of Energy, calls for the "direct" disposal of spent fuel
and high-level radioactive waste in a deep geological repository.
Some scientists, however, believe that it would be advantageous to
transmute (change) spent fuel and high-level radioactive waste to a
less radioactive and less toxic waste form before burying it in a
repository. Transmutation might result in certain benefits, such as
(1) reducing the volume and greatly reducing the radioactive life of
the waste that must be buried and (2) ensuring less risk in certain
situations, such as human intrusion into the repository.
Transmutation of radioactive waste is not a new notion. However,
research and development to make transmutation technology available
and economical for the possible treatment of radioactive waste has
not been done.
This chapter discusses the general process proposed for transmuting
commercial spent fuel and high-level radioactive waste from the
production of nuclear weapons and the claimed advantages of
transmutation. Subsequent chapters discuss (1) some specific
concepts for transmutation, (2) the cost of and schedule for
developing these concepts and treating "existing"\2
radioactive waste, and (3) the practicality of transmutation as a
technology to manage radioactive waste. A glossary of terms is
included at the end of the report.
--------------------
\1 The Department of Energy (DOE) defines "high-level waste" as the
highly radioactive material that results from reprocessing spent
fuel. On the other hand, the Nuclear Regulatory Commission defines
it as both processed and unprocessed spent fuel. For the purposes of
this report, we are using DOE's definition and making a distinction
between spent fuel and high-level waste. When the high-level waste
has been generated as a result of DOE's nuclear weapons production
activities, we may also refer to it as "defense" or "weapons" waste.
\2 In this report, existing spent fuel is defined as that inventory
of spent fuel produced by the current generation of commercial
reactors up until 2030, when DOE expects that these reactors will
have been retired and/or replaced. Existing defense high-level
radioactive waste is that generated from the materials and methods
used to produce plutonium and tritium for nuclear weapons and
currently stored at DOE facilities. Much of this waste was produced
when spent fuel from nuclear materials production reactors was
reprocessed to extract plutonium for further use.
BACKGROUND
---------------------------------------------------------- Chapter 1:1
Transmutation is the conversion of one element into another, such as
the old story of possibly changing lead into gold. However,
transmutation cannot be accomplished chemically. For transmutation
to occur, the nucleus of an atom of an element must be changed, an
event that can occur only through a nuclear reaction in a reactor or
particle accelerator or through radioactive decay. When a
radioactive atom absorbs a neutron, the resulting reaction can
convert the atom into a different one that is stable (nonradioactive)
or into products that have shorter radioactive lifetimes. For
example, transmutation can convert technetium-99 (a radioactive
fission product) into the stable element ruthenium by absorbing a
neutron.
TRANSMUTATION APPLIED TO
COMMERCIAL SPENT NUCLEAR FUEL
---------------------------------------------------------- Chapter 1:2
U.S. commercial light-water nuclear reactors (LWRs) generate about
2,000 metric tons of spent nuclear fuel each year. The current
inventory is about 28,000 metric tons. DOE estimates that this
inventory will increase to about 61,000 metric tons by 2010, when a
waste repository is scheduled to open.\3 The current statutory
capacity limit for this repository is 70,000 metric tons.
The present U.S. policy for handling spent fuel from a commercial
nuclear power plant is to store the fuel elements in a facility at
plant sites and/or at a federally owned storage facility until a
repository for permanent disposal of the spent fuel becomes
available. DOE will then transfer the fuel to that repository for
permanent disposal. The Environmental Protection Agency, which sets
the general environment standards for disposal of highly radioactive
wastes in repositories, believes that the waste should be contained
in the repository for at least 10,000 years.
A small number of radioactive isotopes contained in the spent nuclear
fuel of reactors are responsible for the required long confinement
times for radioactive wastes. Table 1.1 lists the most important of
these long-lived radioactive isotopes (radioisotopes).
Table 1.1
Long-Lived Radioactive Isotopes
Contained in Spent Nuclear Fuel
Isotope Type Half-life in years
-------------------- ------------------ ------------------
Neptunium-237 Transuranic\a 2,000,000
Plutonium-239 Transuranic 24,000
Plutonium-240 Transuranic 6,563
Americium-241 Transuranic 432
Americium-243 Transuranic 7,400
Curium isotopes Transuranic up to 15,600,000
Technetium-99 Fission product\b 210,000
Iodine-129 Fission product 17,000,000
------------------------------------------------------------
\a Transuranic elements are man-made radioactive isotopes produced
from uranium during nuclear reactor operations.
\b Fission products are the radioactive fragments (by-products)
formed by nuclear fission in a reactor--the "ash" of nuclear power
production.
Spent fuel contains uranium, transuranic elements, and fission
products. Plutonium is, perhaps, the best known transuranic. As
shown in table 1.1, transuranic elements have very long radioactive
lives. DOE must consider this longevity when designing disposal
methods for this radioactive waste.
Reducing the time that a repository would contain significant
inventories of radioactive materials requires eliminating uranium and
the radioactive isotopes in table 1.1 from the disposed-of waste.
Uranium isotopes in the spent fuel waste have half-lives ranging into
billions of years. A group of radioactive isotopes, including
transuranics plus uranium, are referred to as "the actinides."
Removal of the actinides from the spent fuel would reduce the average
radioactive lifetime of the waste to be buried in the repository.
Another concern with repository burial is the possible leakage of
soluble radioactive elements. Although actinides retain much higher
toxicity levels for much longer periods than fission products,
actinides are not very soluble, whereas the fission products,
technetium and iodine, are. Thus, the long-term risks of leakage
from a repository are not so much from actinides as from long-lived,
soluble fission products, such as those in table 1.1. Consequently,
transmutation of the long-lived fission products before the waste is
buried would lower the long-term risk from leaks. (DOE repository
officials consider this risk of leakage to be already extremely low.)
Two spent fuel fission products--cesium-137 and strontium-90--with
relatively short half-lives (about 30 years) also require special
consideration, because they are the principal heat sources in the
wastes during the early period of decay. Radioactive isotopes give
off heat energy as they decay. The amount of decay heat limits the
volume of waste that can be put into a geological repository. If the
heat load can be reduced by transmuting part of the waste and/or
allowing the principal heat sources to cool down (cesium-137 and
strontium-90 probably cannot be transmuted) before burial, the
capacity of a repository might be increased. In turn, increased
capacity might lead to the need for fewer repositories.
--------------------
\3 In our report entitled Nuclear Waste: Yucca Mountain Project
Behind Schedule and Facing Major Scientific Uncertainties
(GAO/RCED-93-124, May 21, 1993), we estimate that the scheduled
opening of a repository may slip by 5 to 13 years.
PROPOSED WASTE TREATMENT
PROCESS FOR SPENT FUEL
-------------------------------------------------------- Chapter 1:2.1
Before transmutation of the spent fuel can occur, it has to be
reprocessed, the waste separated into high- and low-level radioactive
components, and the actinides and fission products separated from the
high-level component. The reprocessing and separating of the waste
are more difficult technical problems than transmuting the long-lived
elements from the waste. These problems need to be resolved before
transmutation can be considered an option for treating waste.\4 DOE
is considering both aqueous processes, such as the plutonium and
uranium extraction (PUREX) system that has been used in the
separation of defense waste,\5 and a new process called
"pyroprocessing" now being developed, which uses electrorefining to
separate elements of the reprocessed spent fuel.
Once the waste has been separated, fissionable elements extracted
from the high-level component can be incorporated into new fuel. The
fuel can then be used in a reactor or accelerator, where nuclear
reactions can change the long-lived actinides and, possibly, some
fission products into short-lived or stable isotopes. Not all of
these isotopes would be changed in a single pass; thus, the process
may have to be repeated many times to complete the burning of the
long-lived components of the waste. Transmutation proponents suggest
using an advanced reactor design (more advanced than light-water
reactors)\6 or an accelerator for this process. Figure 1.2 shows a
possible waste transmutation process for treating spent fuel wastes.
Figure 1.1: Processing and
Transmuting Spent Fuel
(See figure in printed
edition.)
Source: GAO's composite of
DOE's diagrams.
(See figure in printed
edition.)
The advanced transmutation facility shown in figure 1.1 could be a
reactor or accelerator that might also be used to generate
electricity. The sale of this electricity could help to offset the
cost of the waste treatment. In addition, as shown, residual
high-level waste from fuel reprocessing and transmutation operations,
including elements of high-level waste that cannot be transmuted,
would have to be disposed of in a repository.
--------------------
\4 Transmutation is only one of the possible waste treatments that
could be used after the spent fuel is reprocessed and separated. For
example, the separated waste streams could be disposed of at that
point, or some waste could be immobilized in a form like glass before
disposal.
\5 Another aqueous process called transuranic extraction (TRUEX) is
also being developed to separate the transuranics from high-level
waste.
\6 The National Research Council is examining the potential use of
light-water reactors for transmutation, as part of its transmutation
study. Officials from DOE's Office of Nuclear Energy suggest using
an advanced reactor, such as the liquid-metal-cooled reactor, because
they (and others) believe that commercial light-water reactors would
be less efficient as waste burners.
TRANSMUTATION APPLIED TO
DEFENSE WASTE
---------------------------------------------------------- Chapter 1:3
A second category of high-level nuclear waste is the defense waste
currently stored in tanks at several DOE facilities, primarily the
Hanford Reservation in Washington; the Savannah River Plant in South
Carolina; and the Idaho National Engineering Laboratory in Idaho.
For example, Hanford has about 61 million gallons of high-level waste
stored in 177 tanks--about 63 percent of DOE's total volume and 37
percent of its radioactivity. DOE has already processed most of the
defense waste to remove the plutonium and unused uranium. However,
the waste still contains small amounts of uranium, plutonium, minor
transuranics, and many fission products, including long-lived ones.
DOE's disposal plan for these defense wastes is to remove them from
the tanks and separate them into high- and low-level components. DOE
would then immobilize the high-level waste in a suitable material
(for example, glass) and send it to a geological repository for
disposal. The low-level components would be immobilized in a
suitable material for storage at the site. As with the commercial
wastes, the assumption is that a repository that can contain the
high-level waste for thousands of years will be available.
Figure 1.2 shows a possible transmutation option for the treatment of
high-level defense waste.
Figure 1.2: Transmutation
Option for High-Level Defense
Waste
(See figure in printed
edition.)
Source: DOE.
(See figure in printed
edition.)
OBJECTIVES, SCOPE, AND
METHODOLOGY
---------------------------------------------------------- Chapter 1:4
The Chairman of the Subcommittee on Energy, House Committee on
Science, Space, and Technology, requested that we obtain information
on the status of U.S. research into the possible transmutation of
radioactive waste. Specifically, the Chairman asked us to
identify current U.S. efforts in the research and development of
radioactive waste transmutation technology;
determine the estimated timing and cost for developing and
implementing transmutation, including any planned demonstration
projects; and
assess the prospects for the practical application of the
transmutation technology to existing commercial spent nuclear
fuel and highly radioactive defense waste.
We conducted work primarily at DOE headquarters, Washington, D.C.;
the Argonne National Laboratory in Illinois and Idaho; the Los Alamos
National Laboratory, New Mexico; the Brookhaven National Laboratory,
New York; and the Hanford Reservation, Washington.
To determine current U.S. research efforts in transmutation, we
analyzed pertinent documents and articles and held discussions at DOE
headquarters with waste management program officials from the Office
of Environmental Restoration and Waste Management and the Office of
Civilian Radioactive Waste Management and representatives of the
Office of Nuclear Energy. We also visited the Hanford Reservation
and three national laboratories that had developed transmutation
concepts and discussed these concepts with their developers. In
addition, we held discussions with representatives of the National
Research Council and members of a Research Council panel established
to study radioactive waste separation and transmutation options.
To estimate the cost and time for development and implementation of
the different transmutation concepts, we held discussions with the
developers of each concept and obtained documents relating to cost
and schedule data for each of the concepts. Much of these data could
be used directly to provide preliminary estimates of cost and timing.
In some cases, we had to analyze the data provided by the developers
to make estimates of the cost and schedule to implement
transmutation. In each case, we had the concept developers review
our analysis and presentation of their respective concepts.\7 All of
these estimates are acknowledged by the developers and us to be very
preliminary because transmutation is in the early research stage.
Nonetheless, we have presented these preliminary estimates in our
report to give the reader a sense of the potential magnitude of the
cost and schedule for development and implementation of radioactive
waste transmutation.
To determine the practicality of developing and applying
transmutation to spent fuel generated by existing nuclear power
plants and to existing highly radioactive defense waste, we examined
the technical, institutional, and financial problems that this
technology has to overcome to be successfully applied. These
problems have been identified by the technical community and have
been reported in pertinent documents. We also examined current
critiques by nuclear industry representatives and the results of
recent studies, including one commissioned by DOE's Office of
Civilian Radioactive Waste Management and performed by DOE's Lawrence
Livermore Laboratory concerning the potential for practical
application of transmutation to spent fuel. In addition, we
discussed the question of the practical application of transmutation
with the promoters of each concept and some members and managers of
the National Research Council panel that is currently studying waste
separation and transmutation for DOE.
Dr. George W. Hinman, D.Sc., provided technical assistance in
performing this review, including developing a technical supplement,
which is the basis for much of this report. Dr. Hinman is currently
the Director of the Office of Applied Energy Studies at Washington
State University and has over 40 years experience in the nuclear
energy field in industry, government, and academia.
If you would like to obtain the technical supplement to this report,
fill out and mail the postcard at the beginning of this report. If
the postcard is missing, send your name and address with your request
for the supplement entitled Nuclear Science: Developing Technology
to Reduce Radioactive Waste May Take Decades and Be Costly
(GAO/RCED-94-16S) to
U.S. General Accounting Office
ATTN: Ms. Roselyn Alston
Room 1842
441 G Street, N.W.
Washington, D.C. 20548
We discussed the contents of this report with DOE representatives,
including the Acting Director of the Office of Strategic Planning and
International Programs, Civilian Radioactive Waste Management; the
Associate Deputy Assistant Secretary for the Office of Technology
Development, Environmental Restoration and Waste Management; and the
Director of the Office of Nuclear Energy. (The Office of Nuclear
Energy sponsors one of the concepts for transmuting radioactive
waste.) In addition, we discussed our report and conclusions with the
project director of the National Research Council's ongoing study of
waste transmutation, who strongly agreed with the report's
conclusions. The representatives from DOE's radioactive waste
management groups also agreed with our report's conclusions. The
Director of the Office of Nuclear Energy agreed that transmutation
still has to be proven to be technically and economically feasible.
However, he said that he is concerned that transmutation research may
not be pursued because, in his opinion, premature judgments are being
made about the potential costs of transmutation. He commented that
it is too early to make accurate estimates of the cost of transmuting
commercial spent fuel. Our report's description of the transmutation
concepts and preliminary estimates of the costs and schedules for
developing and implementing these concepts were reviewed by the
concept developers. These preliminary estimates are presented in our
report to provide a sense of the potential magnitude of the cost and
length of time needed to develop and implement transmutation. Others
with whom we discussed our report and/or who have also studied the
transmutation of radioactive waste agree with the magnitude of these
preliminary estimates. The concept developers, DOE representatives,
and the National Research Council study representative provided
additional information and clarifications, which were incorporated
where appropriate. As requested, we did not obtain written agency
comments. We performed our review between July 1992 and August 1993,
in accordance with generally accepted government auditing standards.
--------------------
\7 Developers of a proposal to use a high-temperature, gas-cooled
reactor to transmute spent fuel did not respond to our request that
they review our presentation of their concept. The four other
concept developers did comply with our request.
DOE'S RADIOACTIVE WASTE MANAGERS
HAVE NOT SUPPORTED TRANSMUTATION
RESEARCH, BUT VARIOUS PROPOSALS
ARE BEING STUDIED
============================================================ Chapter 2
The DOE managers who are responsible for the disposal of commercial
spent nuclear fuel and highly radioactive defense waste are not
actively considering transmutation as a possible method for treating
existing waste. However, a number of DOE laboratories have proposed
waste transmutation concepts, and DOE's Office of Nuclear Energy is
developing an advanced power reactor that may be able to transmute
its spent fuel waste. All of these proposed transmutation concepts
require more research to determine whether they are technically and
economically feasible. DOE has asked the National Research Council
to examine transmutation concepts.
DOE'S RADIOACTIVE WASTE
MANAGERS DO NOT SUPPORT
TRANSMUTATION AS A MEANS TO
SOLVE EXISTING WASTE PROBLEMS
---------------------------------------------------------- Chapter 2:1
DOE's defense and commercial radioactive waste management officials
are generally skeptical about the technical and economic feasibility
of waste transmutation. More importantly, they believe that it is
not necessary and not economically justifiable to transmute the spent
fuel from existing commercial reactors and high-level defense waste
before it is put into a repository.\1 They believe that transmutation
is unnecessary because the radioactive waste can be safely disposed
of without first transmuting it. They point out that a geological
repository will be designed, certified, licensed, and monitored to
ensure that disposed waste is safely contained for thousands of
years. Furthermore, they argue that it is not economically
justifiable to transmute waste, since a repository will still be
needed, even if transmutation is successfully developed, to dispose
of residual high-level wastes from the transmutation process and
high-level waste that cannot be transmuted.
Nevertheless, DOE has concluded that it should obtain an independent
assessment of the benefits and costs of the different waste
transmutation concepts being proposed. Thus, in 1991, DOE
commissioned the National Research Council (the Research Council) to
study the status of radioactive waste separation and transmutation
research.
--------------------
\1 The potential cost of transmuting existing radioactive waste and
the practicality of this proposed waste treatment strategy are
discussed in chapters 3 and 4, respectively.
THE NATIONAL RESEARCH COUNCIL'S
STUDY OF TRANSMUTATION
PROPOSALS
---------------------------------------------------------- Chapter 2:2
The Research Council's report on radioactive waste separation and
transmutation, which is expected to be published in July 1994, will
examine radioactive waste treatment research efforts in the United
States and other countries. According to the Research Council
personnel who manage the study, the report will include (1) a
technical and cost-benefit analysis of separating radioactive wastes
into different waste streams (that is, high-level and low-level)
before disposal and (2) a technical and cost-benefit analysis of
waste separation followed by transmutation. The study panel of
experts is also charged with analyzing the potential impact of
successful development of waste separations and transmutation
technology on the nation's repository strategy for disposal of
radioactive waste. In addition to examining the potential for
transmutation of waste using advanced reactors and accelerators, the
Research Council will also examine the potential for using
light-water reactors to transmute their own spent fuel and to burn up
plutonium extracted from nuclear weapons.
Managers of the Research Council's study told us that the study panel
has found that much research remains to be done in developing
technologies for radioactive waste separation and transmutation.
Specifically, the study managers said the panel believes that some of
the U.S. proponents of transmutation may have exaggerated the
potential benefits and underestimated the costs and the technical and
institutional problems involved with their proposed method for
transmutation; or more likely, the proponents have not done enough
actual research to determine the technical and economic feasibility
of their proposals.
TRANSMUTATION CONCEPTS FOCUS ON
SPENT FUEL
---------------------------------------------------------- Chapter 2:3
Although radioactive defense waste is also a candidate for
transmutation, the developers of the transmutation concepts have
mainly concentrated on the possible treatment of commercial spent
fuel. The proponents of transmutation consider unprocessed spent
fuel a larger and more likely candidate for transmutation. In
addition, DOE's waste managers have told transmutation proponents
that DOE has already selected the scheme for disposal of defense
waste--separation and disposal after immobilization. These managers
are concentrating on developing methods to characterize, separate
(into high-level and low-level wastes), and immobilize (for example,
in glass for high-level waste) defense wastes prior to disposal.
The remainder of this chapter describes the five concepts that have
been identified as methods for possible transmutation of radioactive
waste. The basic setup for each concept to process and transmute
spent fuel is similar to that shown in figure 1.1; the advanced
transmutation facility shown in figure 1.1 may be either a reactor or
an accelerator.
MORE RESEARCH IS NEEDED TO
DETERMINE FEASIBILITY OF
PROPOSED WASTE TRANSMUTATION
CONCEPTS
---------------------------------------------------------- Chapter 2:4
Four national Laboratories have identified five concepts for the
transmutation of radioactive waste. All of the concepts require more
research to determine whether they are technically and economically
feasible. The proposed concepts include three reactor- and two
accelerator-driven transmutation systems: the Advanced
Liquid-Metal/Integral Fast Reactor (ALMR/IFR) program (sponsored by
DOE's Office of Nuclear Energy) at the General Electric Company and
the Argonne National Laboratory; the Particle-Bed Reactor program at
Brookhaven National Laboratory; the Westinghouse-Hanford Clean Use of
Reactor Energy (CURE) program at the Hanford Reservation; the
Accelerator Transmutation of Waste (ATW) program at Los Alamos
National Laboratory; and the Phoenix accelerator program at
Brookhaven National Laboratory. The ALMR/IFR transmutation concept
is furthest along. However, the other concepts claim greater
transmutation capabilities than the ALMR/IFR.
ALMR/IFR TRANSMUTATION
CONCEPT IS FURTHER ALONG
THAN THE OTHER OPTIONS
-------------------------------------------------------- Chapter 2:4.1
Although the ALMR/IFR transmutation concept is still very much in the
research stage, it is the most developed because it has been part of
a larger program that has historically received substantial funding.
DOE's ALMR/IFR transmutation efforts have been part of DOE's effort
to develop and field an advanced power reactor. This effort extends
back into history more than a decade and includes the Clinch River
breeder reactor project. DOE's planned ALMR would be cooled by
liquid metal (sodium), use metal fuel (a mixture of plutonium,
uranium, and zirconium), and be able to breed its own fuel, if
necessary. Besides this unique and advanced design, the reactor
would also have a "closed fuel cycle." In the closed fuel cycle,
spent fuel from the reactor would be reprocessed, and the actinides
would be separated from the other wastes (the fission products),
incorporated into new metal fuel, and fed back into the reactor.
This process would enable the reactor to eventually burn up
(transmute) its spent fuel actinide waste.
THE ALMR/IFR TRANSMUTATION
PROCESS APPLIED TO
LIGHT-WATER REACTOR SPENT
FUEL
-------------------------------------------------------- Chapter 2:4.2
Promoters of the ALMR/IFR concept believe that they can reprocess and
separate into different components the spent fuel from existing
commercial light-water-cooled reactors and then incorporate the
high-level actinide wastes in new metal fuel that can be used in the
ALMR/IFR. The ALMR/IFR system would burn this fuel, reprocess it,
separate it, refabricate it, and burn it again in a continuous cycle
until the actinides are destroyed.
ALMR/IFR program officials are developing a nonaqueous system, called
pyroprocessing, for separating spent ALMR metal fuel into different
components. A key step in the process uses electrorefining to
separate the usable actinides from the spent fuel fission products.
Program officials claim that pyroprocessing will be less expensive
and more efficient than the currently more developed aqueous
(chemical solvent) methods. Others in the nuclear industry are
skeptical and are waiting for ALMR/IFR developers to provide proof.
Although the ALMR/IFR may prove to be an effective burner of
actinides, it cannot transmute the fission products contained in
spent fuel. According to program officials, these fission products
will be separated out for direct burial or other treatment.
Proponents argue that the ability to reprocess spent LWR fuel and use
its actinides as a fuel in the ALMR/IFR is likely to be less
hazardous to human health and cost less than mining and milling new
uranium ore for reactor fuel.\2 Others argue that fuel reprocessing
and other processes involved with the transmutation of spent LWR fuel
may be as hazardous to workers as mining and milling uranium.
In May 1992, at the direction of the former Secretary of Energy, the
National Research Council issued a report specifically on the option
of using the ALMR/IFR for transmutation of radioactive waste.\3 The
report concluded that the ALMR/IFR transmutation system had the
potential to reduce the amount of actinide waste from spent fuel that
would have to be buried in the repository. However, the Research
Council stated that the ALMR/IFR system for transmuting and
eventually destroying spent fuel waste would likely be costly and
take many decades to complete.
Specifically, the Research Council reported that it would take 20
ALMR/IFRs 100 years or more to destroy 90 percent of the LWR actinide
waste inventory that is expected to exist in 2010, when a geological
repository is scheduled to open. Residual high-level wastes,
including the long-lived fission products contained in spent fuel,
would still have to be disposed of in a repository.
--------------------
\2 Operating the ALMR/IFR as a fuel-breeding reactor would also
diminish the need for mining and milling uranium ore, and on a much
larger scale.
\3 Interim Report of the Panel on Separations Technology and
Transmutation Systems, the National Research Council, May 1992.
LESS-DEVELOPED CONCEPTS
CLAIM ADVANTAGES OVER THE
ALMR/IFR
-------------------------------------------------------- Chapter 2:4.3
The four other transmutation concepts--two reactor and two
accelerator systems--although not as well explored as the ALMR/IFR,
claim some advantages over it. Specifically, the promoters of each
of the other concepts claim that their concept will be able to
transmute not only actinides but also some of the long-lived fission
products from spent fuel. In addition, the accelerator concepts
claim to be safer than the reactor-driven concepts because, unlike
the reactors, they do not need to sustain a nuclear chain reaction
and can be shut down instantly if a problem occurs. These concepts,
although possibly promising, have not been researched beyond
theoretical studies, mainly because of a lack of funding.
BROOKHAVEN LABORATORY'S
PARTICLE-BED REACTOR AS A
WASTE BURNER
-------------------------------------------------------- Chapter 2:4.4
Brookhaven's Particle-Bed Reactor (PBR) is so named because the fuel
is contained in small, graphite-coated particles that form the
"particle bed." Brookhaven had been developing the PBR for the Air
Force as a possible propulsion system for space flights. According
to program officials, the Air Force ordered Brookhaven to stop its
PBR propulsion efforts in 1993 as part of the administration's cost
savings program. Brookhaven scientists, however, had also proposed
using the PBR to transmute radioactive waste and recommended to DOE
that a research and development program be started to investigate
this possibility.
The PBR is a proposed small, high-temperature, helium-cooled reactor.
Although only brief conceptual studies have been done, Brookhaven
officials believe that the PBR would effectively transmute both
actinides and fission products. These officials believe that the PBR
concept is more attractive than the ALMR/IFR because, according to
program officials, the PBR is expected to be able to destroy both
actinides and fission products, while accumulating very low residual
waste inventories from burn cycle to burn cycle. The ALMR/IFR
maintains a large actinide inventory in its core and may take decades
or more to completely burn up the inventory of actinides built up in
spent LWR fuel.
HANFORD'S CLEAN USE OF
REACTOR ENERGY CONCEPT
-------------------------------------------------------- Chapter 2:4.5
The Westinghouse-Hanford's Clean Use of Reactor Energy concept
involves an integrated system of chemical processing and reactor
transmutation to eliminate most long-lived waste components from
high-level radioactive waste. CURE proposes examining a variety of
chemical processing and transmutation systems. However, CURE
highlights a system that uses aqueous processing (for example, PUREX
or TRUEX) and separation of spent LWR fuel combined with fissioning
of transuranic elements in an oxide-fueled, liquid-metal-cooled
reactor. This differs from the ALMR/IFR proposal to use
pyroprocessing and a metal-fueled reactor. In addition, the CURE
reactor would transmute the long-lived fission products iodine-129
and technetium-99.
The CURE concept is based on theoretical studies; proponents suggest
that the U.S. government, perhaps in collaboration with other
countries, start a research and development program to investigate
and develop this concept.
LOS ALAMOS NATIONAL
LABORATORY'S ACCELERATOR
TRANSMUTATION OF WASTE
-------------------------------------------------------- Chapter 2:4.6
The Los Alamos National Laboratory (LANL) proposes using a particle
accelerator to transmute radioactive waste. This LANL concept,
referred to as the Accelerator Transmutation of Waste program, uses a
linear accelerator to bombard a "target" fabricated from LWR spent
fuel actinides and long-lived fission products and thus transmute
these elements. In addition, as discussed in chapter 3, ATW program
officials are the only transmutation proponents (discussed in this
report) who have seriously considered transmuting defense radioactive
waste.
ATW program officials claim several advantages for their method of
transmuting waste. First, unlike a reactor, the ATW does not need to
maintain a nuclear chain reaction to operate, and it can be shut down
instantly. Thus, proponents claim that the ATW will be safer to
operate because it has a much lower chance of a nuclear accident. In
addition, more rapid transmutation is possible with smaller
inventories of actinides than need to be maintained in the ALMR/IFR
fuel cycle. Furthermore, unlike the ALMR/IFR, the ATW claims to also
transmute some fission products. For example, the ATW would
transmute into stable isotopes the fission products iodine-129 and
technetium-99, which have half-lives of 17 million and 0.2 million
years, respectively.
BROOKHAVEN NATIONAL
LABORATORY'S PHOENIX
TRANSMUTATION SYSTEM
-------------------------------------------------------- Chapter 2:4.7
Brookhaven National Laboratory officials have proposed that the
laboratory's Phoenix accelerator be used to transmute waste. The
Phoenix would be part of a larger radioactive waste treatment system
that the officials are proposing. The system would include
processing and separating spent commercial nuclear fuel into key
components. The Phoenix system would transmute some of these
components, others would be stored for later use, and still others
would be deposited into a repository after the separation process.
The Phoenix concept, like the ATW concept, proposes to use a linear
accelerator to transmute "minor" actinides (neptunium, americium, and
curium) and the fission product iodine-129. The Phoenix concept
relies heavily on the PUREX and TRUEX chemical processing systems to
prepare the accelerator target material from spent LWR fuel and to
reprocess the accelerator-bombarded nuclear material targets after
they have been irradiated. Unlike the ATW, the Phoenix would not
transmute plutonium or uranium. Instead, these would be separated
from the processed spent fuel and stored for possible future use.
The plutonium and uranium might be used as fuel in current or future
reactors.
Brookhaven officials claim that only one Phoenix system (or perhaps
two) would be needed to transmute the inventory of minor actinides
that would be contained in the spent fuel generated by the current
generation of commercial reactors. These officials also believe that
the proposed Phoenix waste treatment system could reduce the risk
period for radioactive toxicity of high-level waste from the current
10,000 years down to approximately 30 years.
CONCLUSION
---------------------------------------------------------- Chapter 2:5
Proponents of the five transmutation concepts present optimistic
claims for the potential application of transmutation technology to
the existing radioactive waste problem. However, with the exception
of ALMR/IFR, very little actual research and development has been
done to verify claimed transmutation capabilities and benefits.
Furthermore, no determination has been made of the economic and
technical feasibility of any of the concepts, including the ALMR/IFR
concept. It is difficult to verify any claims about the potential
capabilities and benefits of any of the proposed waste transmutation
concepts without sufficient research to document these attributes.
Perhaps the forthcoming National Research Council study will resolve
some of this uncertainty.
PRELIMINARY ESTIMATES TO DEVELOP
AND IMPLEMENT TRANSMUTATION ARE
HIGH
============================================================ Chapter 3
Preliminary data from the proponents of each transmutation concept
represent very early and incomplete estimates, but these estimates
show that it could cost billions of dollars (in 1993
dollars)--perhaps as much as $29 billion, depending on the concept
selected--to develop and construct an initial system that could
transmute LWR spent fuel. Additional tens of billions of dollars
would be needed to build the additional systems that would be used to
transmute the accumulated inventory of spent fuel from existing
light-water reactors. An analysis of data supplied by the proponents
of the various concepts shows that initial commercial operations to
transmute light-water reactor spent fuel could begin about 2015 and
could take until 2050 to 2240 (depending on the method and extent of
transmutation) to treat the spent fuel that would have accumulated by
2030.\1 According to data from the developers of transmutation
concepts, the actual processing and transmutation of the spent fuel
could cost additional tens of billions to over $100 billion dollars.
However, transmutation proponents believe that part or all of these
costs could be recouped by generating and selling electricity,
assuming that the price of the electricity generated is competitive
with other possible sources.
The following is a discussion of the estimated cost of and schedule
for developing and implementing each of the proposed transmutation
systems. The proposals are for systems that would transmute spent
fuel; only the ATW system has studied the possibility of transmuting
defense waste. The estimates are very early and unverified estimates
made by the proponents of each transmutation concept or, in some
cases, made by us using information supplied by the proponents. The
estimates from each proposal are not comparable because they are
incomplete and represent estimates of somewhat different strategies
for treating the waste. We are presenting these estimates only to
give the reader a sense of the potential cost and time requirements
for transmuting spent fuel waste.
--------------------
\1 DOE expects that all of the current generation of U.S. nuclear
power reactors will have been retired and/or replaced by 2030 and
will have generated about 90,000 metric tons of spent fuel.
ALMR/IFR'S ESTIMATED COST AND
SCHEDULE
---------------------------------------------------------- Chapter 3:1
DOE's preliminary cost estimates for an ALMR/IFR system to transmute
LWR spent fuel are incomplete. However, DOE's cost estimates to
develop and construct just the power reactor and a facility to
recycle its metal fuel exceed $5 billion (in 1993 dollars).
Additional facilities costing billions of dollars more would also be
needed for a complete system to transmute the LWR spent fuel.
DOE developed a draft 5-year ALMR/IFR program plan in response to a
requirement of the Energy Policy Act of 1992. In the plan, program
officials estimated that approximately $900 million would be needed
from 1993 to 1998 for reactor design and development, fuel-cycle
research and development, and LWR spent fuel recycle research.
Additional funding would be required, including about $2.9 billion to
construct the first ALMR power reactor and about $1.3 billion for a
facility to recycle the reactor's metal fuel. However, to transmute
LWR spent fuel, the ALMR/IFR system would also need a reprocessing
and refabrication facility for LWR spent fuel, as well as facilities
to temporarily store spent fuel waiting to be processed and residual
waste waiting to be buried. A DOE program manager said that an
official estimate of the cost of an LWR reprocessing facility has not
been made because a detailed design of a possible facility has not
been done this early in the program. However, he said that such a
facility could cost several billion dollars.\2
ALMR/IFR program officials believe that with "adequate" funding they
could demonstrate a complete system by about 2010 and then field a
first commercial ALMR/IFR transmutation system and start treating LWR
spent fuel waste by 2014. Data provided by ALMR/IFR officials show
that an additional 200 years, 18 more ALMR/IFR systems, and
additional tens of billions of dollars might be needed to treat the
existing inventory of spent fuel. Proponents of the ALMR/IFR believe
that all of these costs could be offset by sales of electricity,
assuming that the cost of generated electricity is competitive with
other possible sources.
--------------------
\2 DOE's Office of Nuclear Energy is currently using an estimated
cost for reprocessing a unit of LWR spent fuel in lieu of actually
estimating the development and capital cost of a LWR fuel
reprocessing facility.
A SCENARIO FOR ALMR/IFR'S
TREATMENT OF EXISTING LWR
WASTE
-------------------------------------------------------- Chapter 3:1.1
ALMR/IFR program officials describe a scenario involving 19 ALMR/IFR
plants to transmute the inventory of spent fuel from the current
generation of LWRs that will have ceased operation by 2030. DOE
estimates that by 2030 this generation of LWRs will have produced an
inventory of about 90,000 metric tons of spent fuel waste--about 875
metric tons\3 of which will be actinides. The ALMR/IFRs would use
these actinides as fuel. Data from the ALMR/IFR scenario show that
the inventory of actinide wastes from the spent fuel could be reduced
to less than one metric ton by 2240. Residual waste from the
reprocessing and high-level waste that could not be transmuted would
still require repository burial. However, program officials say that
the volume and long-term radioactivity of this waste will be greatly
reduced when compared with the original spent fuel.
Each of the 19 ALMR/IFRs would cost about $4 billion (1993 dollars),
including a power reactor and a metal fuel recycling facility,
according to program officials. However, program officials propose
that the 19 ALMR/IFRs replace any existing LWRs scheduled for
retirement and replacement.\4 In addition, they believe that the sale
of electricity generated by the ALMR/IFR would offset transmutation
costs. LWR fuel reprocessing facilities and temporary storage
facilities would be needed at additional capital costs. Program
officials have not estimated the cost or number of these facilities.
However, program reports indicate that it could cost as much as $32
billion (1993 dollars) to transmute the inventory of LWR spent fuel
that will have accumulated by the year 2030. ALMR/IFR program
officials say that transmuting costs could be added to the price that
they would charge customers for the electricity to be generated by
the operation.
During the discussion of our draft report with officials from DOE's
Office of Nuclear Energy (sponsor of the ALMR/IFR), they told us that
they were concerned that critics' estimates of the costs to develop
and operate the ALMR/IFR were too high. DOE civilian waste managers,
the Electric Power Research Institute, and even the National Research
Council in its interim report state that ALMR/IFR's development and
transmutation costs are likely to be quite high, stretching into the
tens of billions. Officials from DOE's Office of Nuclear Energy told
us that to counter these claims of high costs, they commissioned the
Oak Ridge National Laboratory to do an ALMR/IFR cost feasibility
study using assumptions and input data provided by their office. The
results of this June 1993\5 study show that it may be less expensive
to operate ALMR/IFRs than light-water reactors if the capital costs
of the two types of plants are the same and if there is (1) a
resurgence in the U.S. demand for nuclear power in the next century,
(2) a large increase in the cost of uranium used to fuel light-water
reactors, and (3) if the ALMR/IFR program is able to develop and
operate its pyroprocessing system (for separating actinides from
spent light-water reactor fuel) for a much lower cost (about
one-third) than aqueous separation. Others, including DOE's
radioactive waste managers and representatives of the National
Research Council's study panel, are skeptical about a large rise in
the cost of uranium fuel and a much lower cost for pyroprocessing
than is obtainable with aqueous processing systems.
--------------------
\3 The scenarios considered in this report for transmutation of spent
fuel assume that all of the actinides are available for
transmutation--none would have been buried in a repository.
\4 If this replacement does not occur, then each new ALMR/IFR would
represent additional billions of dollars in unscheduled capital
costs.
\5 ALMR Deployment Economic Analysis, Oak Ridge National Laboratory,
June 1993.
BUDGET CUTS MAY AFFECT
PLANNED DEMONSTRATION
PROJECT AND STRETCH OUT
ALMR/IFR DEVELOPMENT
-------------------------------------------------------- Chapter 3:1.2
Although funding for the ALMR/IFR program may be affected by the
administration's effort to reduce the cost of government operations,
program officials hope to at least obtain enough funding in fiscal
year 1994 and subsequent years for fuel-cycle research, including
demonstrating that a pyroprocessing system can be used to separate
LWR spent fuel into actinides and fission products. Program
officials hope to complete this demonstration by 1998. The funding
needed to completely support the ALMR/IFR program amounts to about
$140 million to $150 million (in 1993 dollars) annually. Most of
this amount is operating costs for support facilities. However,
ALMR/IFR program officials expect that about $30 million of this
annual amount would go to fuel-cycle research, including
demonstrating the pyroprocessing of LWR spent fuel. ALMR/IFR program
officials emphasize that unless sufficient funding is obtained, the
accomplishments envisioned in their draft program plan (discussed
above) may be stretched out for decades or completely lost. ALMR/IFR
program officials expect to revise their program plan after the
budget process for fiscal year 1994 is completed.
ATW'S ESTIMATED COST AND
SCHEDULE
---------------------------------------------------------- Chapter 3:2
ATW officials at the Los Alamos National Laboratory estimate that it
would cost about $2.9 billion (1993 dollars) to develop the ATW,
including an estimated $2.1 billion to construct an accelerator.
This preliminary estimate does not include the cost to develop and
construct a facility to reprocess the spent fuel from the LWRs and to
fabricate targets (for accelerator bombardment) from the separated
actinides and fission products of the spent fuel. ATW officials
assume that with DOE's support and funding they could have a
demonstration plant finished by fiscal year 2007--about 14 years from
start to finish. Analysis of program data shows that with a
successful demonstration of the ATW and additional funding, program
officials could construct and start operating a full-scale
transmutation plant by about 2016.
A SCENARIO FOR ATW'S
TREATMENT OF SPENT FUEL FROM
EXISTING LWRS
-------------------------------------------------------- Chapter 3:2.1
If the same scenario described above for the ALMR/IFR is applied to
the ATW, 19 ATW transmutation systems could be constructed between
2016 and 2030. These ATW systems could transmute the inventory of
spent fuel accumulated to 2030 (including actinides and fission
products) by 2055. According to proponents, the ATW system would
destroy the LWR spent fuel waste faster and to a greater extent (that
is, including fission products) than the ALMR/IFR. Preliminary
estimates by ATW program officials show that the cost for transmuting
the inventory of spent fuel might exceed $120 billion (1993 dollars).
Program officials say that the ATW system would also generate and
sell electric power to help offset transmutation costs.
ATW TRANSMUTATION OF DEFENSE
WASTE
-------------------------------------------------------- Chapter 3:2.2
The ATW is the only transmutation concept that has seriously studied
and proposed a transmutation system for defense waste. The ATW
program officials developed a theoretical process for possible
transmutation of the defense wastes currently stored in tanks at the
Hanford Reservation. (Fig. 1.2 portrays the option for transmuting
defense waste.) The capital cost of such a system would be similar to
that discussed for ATW treatment of spent fuel. However, the system
probably would not include an option for generating power. If a
power facility is not included, start-up costs would be lower. Net
operating costs may increase however, because there would be no sale
of electricity to help offset the cost of transmutation. DOE defense
waste managers have told ATW program officials that they do not
consider transmutation to be necessary or cost-beneficial for
treatment of the Hanford tank waste.
PHOENIX TRANSMUTATION SYSTEM'S
ESTIMATED COST AND SCHEDULE
---------------------------------------------------------- Chapter 3:3
Brookhaven National Laboratory (BNL) officials estimate that it might
cost as much as $29 billion (1993 dollars) to develop and field a
Phoenix system that could transmute radioactive waste. They believe
that $20 billion of this estimated cost may be needed to develop the
waste separations' technology, including construction of a large
spent fuel reprocessing facility to supply the Phoenix accelerator
with material to be transmuted. Also included in the estimate are $1
billion to $2 billion to construct the accelerator and $7 billion for
a power plant, if they elect to generate and sell electric power.
The officials estimate that it would probably take 15-20 years to put
this technology on line.
A SCENARIO FOR PHOENIX
TREATMENT OF EXISTING LWR
SPENT FUEL
-------------------------------------------------------- Chapter 3:3.1
Brookhaven proposes that the Phoenix be used to transmute only the
minor actinides (neptunium, americium, and curium) plus iodine-129
but not plutonium. Therefore, the scenario for spent fuel waste
treatment in this case is not comparable to that of the ALMR/IFR. In
addition, unlike the other concepts, Phoenix officials propose
building one large facility that could service the reprocessing of
spent fuel from 75 LWRs. Development and construction of this large
reprocessing facility would increase the cost of the first Phoenix
system compared with the possible cost of first complete systems for
the other concepts, but overall the Phoenix might require only one or
two total systems compared with perhaps 20 for the others.
According to concept developers, one full-scale Phoenix system could
transmute 2.6 metric tons of minor actinides per year. The total
inventory of minor actinides built up in LWR spent fuel by 2030, when
the current generation of LWRs is expected to cease operation, is
expected to be about 58 metric tons. Therefore, one Phoenix could
transmute this inventory of minor actinides in about 25 years. The
operation might have to be extended somewhat to complete the
simultaneous transmutation of iodine-129. Program officials estimate
that if a Phoenix transmutation system was fielded and started
operation about 2015, the minor actinides and iodine-129 would be
disposed of sometime between 2035 and 2050. However, about 817
metric tons of plutonium from the spent fuel would still remain.
Brookhaven officials have not estimated what it would cost for the
Phoenix to transmute the minor actinides plus iodine-129.
PBR'S ESTIMATED COST AND
SCHEDULE
---------------------------------------------------------- Chapter 3:4
Brookhaven National Laboratory officials estimate that it would cost
about $1.3 billion (1993 dollars) and take about 16 years to develop
and demonstrate the PBR's transmutation capability. This estimate
includes the reactor and particle fuel processing and fabrication
system but does not include developing the technology and building a
facility to reprocess the spent LWR fuel and refabricate it into
particle fuel for the PBR.
BNL officials believe that they could build a transmutation
demonstration plant by 2010. Then, if this is successful, 20 PBR
transmutation systems could be built over the next two decades. An
analysis of program data shows that these PBRs could dispose of the
LWRs' minor actinide waste by 2050.\6 However, it might take until
2160 to destroy the much larger inventory of plutonium and the
fission products, technetium and iodine. BNL officials describe
other transmutation scenarios involving as many as 70 PBRs, with
correspondingly shorter times required to treat the inventory of LWR
spent fuel. PBR program officials have not estimated what it would
cost to operate the PBR transmutation system.
--------------------
\6 PBR program officials were asked to review our analysis and
presentation of the data they provided us on their transmutation
concept. However, they did not comment. One program official told
us that they were occupied with reorganization after the loss of Air
Force funding for their program.
CURE SYSTEM'S ESTIMATED COST
AND SCHEDULE
---------------------------------------------------------- Chapter 3:5
The proponents of the CURE concept at Westinghouse-Hanford estimate
that a research program to resolve technical issues involved with
transmutation would cost between $74 million and $160 million (1993
dollars), depending on the extent of the research. Proponents,
however, have not estimated the cost for construction of a
transmutation demonstration plant or a fuel- reprocessing facility or
the estimated cost of reprocessing and transmuting existing spent
fuel inventories.
According to the developer of the CURE concept, the CURE waste
treatment proposal is much more ambitious than the other proposals.
For example, CURE considers phasing out U.S. nuclear power over a
period of about 100 years and using what it calls "cleanup fast
reactors" to completely dispose of all spent fuel inventories.
Proponents claim that cleanup reactors would reduce the inventories
of the fission products technetium and iodine to one percent of their
original amounts in less than 100 years.
CONCLUSIONS
---------------------------------------------------------- Chapter 3:6
The cost of developing and implementing the transmutation technology,
including developing the process needed to separate light-water
reactor spent wastes prior to transmutation, is expected to be
high--tens of billions of dollars or more. This cost would be in
addition to funding needed to develop and construct a repository,
which most agree will still be necessary even with successful
transmutation of existing waste. Consequently, proponents of the
transmutation of existing spent fuel will have to make a compelling
case for the benefits of transmutation in order to compensate for its
high additional cost.
ANY PRACTICAL APPLICATION OF
TRANSMUTATION IS AT LEAST DECADES
AWAY
============================================================ Chapter 4
A number of problems and circumstances are expected to delay, or even
prevent, any practical application of transmutation technology to the
existing radioactive waste problem. These include a mixture of
opinions on the feasibility and benefit of transmuting existing
waste; the high cost and length of time to develop and field a system
to process and transmute existing waste; the technical and
institutional problems that would have to be overcome; and the lack
of funding and apparent lack of interest by DOE's waste managers and
representatives of the electric power industry to aggressively pursue
the transmutation technology.
Nevertheless, the ability to transmute waste might be a desirable
design attribute for any future generation of nuclear power plants
that might be introduced, assuming that transmutation could be proved
to be technically and economically feasible and assuming that the
demand for nuclear power in the United States will continue and
increase. With transmutation capability inherent in their design,
future generations of nuclear power plants would be able to destroy
much of the radioactive waste that they generate.
MIXED OPINIONS ON THE
PRACTICALITY OF WASTE
TRANSMUTATION
---------------------------------------------------------- Chapter 4:1
A mixture of opinions exists on the practicality of developing
transmutation technology to treat existing radioactive waste. Those
that have concepts (either reactor-based or accelerator-based) to
sell, favor pursuing transmutation. For example, ALMR/IFR program
officials are now promoting their reactor primarily on the basis of
its potential as a radioactive waste burner. Its original stated
purpose was as an advanced power reactor that could breed its own
fuel. Others, such as accelerator proponents, would also like to see
their programs funded. On the other hand, those in DOE who are
responsible for the disposal of radioactive waste seem only remotely
interested in transmutation of waste and are not supporting
transmutation research. They support the direct burial of
radioactive waste or possibly, in the case of high-level defense
waste, burial after waste separation but not transmutation. These
officials point out that promoting transmutation may obscure the fact
that the absolute risk of releases of radioactivity from proposed
geologic repositories is very low. In addition, DOE's radioactive
waste managers are concerned that all the talk about transmutation
may raise false hopes about the need for a repository. Most experts
agree that, regardless of any successful demonstration of
transmutation, a repository will be needed to dispose of residual
waste and the multitude of radioactive isotopes that cannot be
transmuted. In addition, critics also point out that proposals to
transmute existing high-level defense waste and commercial spent fuel
may be inconsistent with current national policy that calls for the
direct disposal of these radioactive wastes (without recycling or
reprocessing) in a deep geological repository.
Critics of transmutation also cite the results of a recent study by
the Lawrence Livermore Laboratory strongly questioning the benefits
of waste transmutation.\1 This 1992 report, commissioned by DOE's
Office of Civilian Radioactive Waste Management, concluded that the
pursuit of transmutation involves large costs and few benefits. Much
of this same sentiment is echoed in studies conducted by the electric
power industry representative--the Electric Power Research Institute
(EPRI)--which has concluded that the costs of transmutation would be
high, benefits modest, and acceptability by industry and the public
questionable.
--------------------
\1 Impacts of New Developments in Partitioning and Transmutation on
the Disposal of High-Level Nuclear Waste in a Mined Geologic
Repository, Lawrence Livermore National Laboratory, March 1992.
IMPLEMENTATION COST AND TIME
MAY MAKE TRANSMUTATION
IMPRACTICAL FOR EXISTING WASTE
PROBLEM
---------------------------------------------------------- Chapter 4:2
As discussed in chapter 3, transmutation technology is expected to
cost billions of dollars to develop and tens of billions of dollars
or more to apply to existing waste and take decades to hundreds of
years to complete. Furthermore, a repository (costing as much as $30
billion, according to DOE) would still be needed to store the
residual waste from this treatment process. In addition, the
fielding of this technology may not be timely enough to have any
effect on the design or schedule of a first repository or even,
perhaps, a second repository that might be needed for storage of
radioactive waste.
Although the schedule for opening a waste repository may slip further
into the future, DOE's current plans call for opening a first
repository in 2010 and making a decision on the need and schedule for
a second repository between 2007 and 2010. Those promoting waste
transmutation estimate that, with sufficient funding and an
aggressive DOE program, they could develop an initial commercial
system and start transmuting waste by about 2015. Then it could take
until 2050 to perhaps 2240 (depending on the concept selected and the
extent of transmutation to be performed) to treat the spent fuel from
existing LWRs that will have accumulated by the year 2030. A first
repository is expected to be needed regardless of any successful
demonstration of transmutation. Although the development and
subsequent application of transmutation to spent fuel waste could
conceivably increase the capacity of this repository, DOE probably
will not have transmutation technology developed and implemented in
time to affect the design and regulations governing the first
repository. In addition, unless DOE aggressively pursues the
development of transmutation technology, it may not be a
consideration in the design or scheduling of a second repository.
Furthermore, some waste treatment experts believe that once a
repository is built and funds are already committed, there may be
little justification to pursue the transmutation of existing waste
because the repository will already have been certified as able to
safely store radioactive waste for thousands of years. In addition,
repository proponents believe that once a first repository has been
successfully opened, it will be easier and less expensive to open a
second, if needed.
CHALLENGES TO DEVELOPING AND
IMPLEMENTING WASTE
TRANSMUTATION
---------------------------------------------------------- Chapter 4:3
A number of technical and institutional challenges may prevent or at
least delay any demonstration of the practical application of
transmutation technology. For example, most technical challenges
still must be identified, researched, and resolved, because the
transmutation concepts are still in their early stages. Furthermore,
institutional challenges, including licensing requirements and public
acceptance, must be overcome before DOE can field any transmutation
system.
TECHNICAL CHALLENGES TO
FIELDING A TRANSMUTATION
SYSTEM
-------------------------------------------------------- Chapter 4:3.1
All of the transmutation options, except the ALMR/IFR, are at a very
early conceptual stage and are essentially unfunded. If funded, they
must overcome all of the technical challenges inherent in developing
a new technology. Although the ALMR/IFR concept is further
developed, program officials must overcome major technical
challenges. For example, ALMR/IFR program officials must demonstrate
the economic and technical feasibility of the proposed ALMR/IFR fuel
cycle, including reprocessing, refabricating, and reburning spent
fuel wastes. ALMR program officials believe that their proposed
pyroprocessing system will be more economical and more efficient than
existing aqueous processing methods. The demonstration of the
ALMR/IFR's fuel cycle capability must be thorough enough to convince
industry to support the ALMR/IFR.
Since the proposed ALMR/IFR transmutation of waste depends on the
successful development and demonstration of the ALMR/IFR as a power
reactor, a number of technical challenges to the ALMR/IFR's power
generation system also need to be resolved. For example, in order to
gain industry support for the ALMR/IFR, DOE must demonstrate that it
will be safer and more economical to build and operate than current
and planned advanced light-water reactors. This includes
demonstrating that the metal fuel that DOE plans to use in the
ALMR/IFR is superior to other types. Some, including EPRI, are not
convinced that metal fuel is the best fuel to use in a
liquid-metal-cooled reactor. EPRI points out that much research and
demonstration remains to be done before the nuclear power industry
will accept the metal fuel.\2 In addition, further testing of the
fuel may be difficult because DOE's test facilities at the Argonne
West Laboratory in Idaho may be shut down or perhaps cut back as a
cost-savings measure. In addition, DOE earlier shut down its other
fuels-testing facility (the Fast Flux Test Facility) at the Hanford
Reservation. DOE officials said that testing the fuel in other
countries is an option if the Argonne test facility is not available.
EPRI has stated that development and demonstration of metal fuel
along with other components, such as steam generators for a
liquid-metal reactor power plant, are crucial to industry acceptance
of the ALMR/IFR. In its interim report on the ALMR/IFR, the National
Research Council, like EPRI, suggests that the ALMR/IFR not be
fielded under the guise of its transmutation capability; instead, it
should be justified on the basis of a demonstration that it is safer
and more economical to operate than light-water-cooled reactors. The
Manager of Argonne's IFR program agrees that the ALMR should first
prove its merits as a future generation power reactor and is
confident that it eventually will, if sufficient funding is obtained.
--------------------
\2 The industry standard is an oxide-based nuclear fuel, not metal
fuel.
INSTITUTIONAL AND PUBLIC
CHALLENGES TO FIELDING A
TRANSMUTATION SYSTEM
-------------------------------------------------------- Chapter 4:3.2
Because of the lack of popularity of nuclear power in the United
States and other institutional and economic barriers, utility
companies have not ordered any new reactors for over a decade--the
growth of nuclear power in the United States has stopped. In
addition, DOE is finding it difficult to establish an interim storage
facility and a permanent disposal repository for radioactive waste
because of public opposition. Furthermore, there is no guarantee
that transmuting waste and thus reducing the radioactivity and volume
of waste to be disposed of would make the repository or the use of
nuclear power any more acceptable to the public.
Any attempt to field a transmutation system can be expected to
encounter similar opposition. Transmutation involves developing,
constructing, and licensing a variety of nuclear facilities. New
technology reactors and/or accelerators and reprocessing facilities
must be acceptable to government institutions and the public. New
licensing standards may have to be developed for these new technology
facilities. Under some waste transmutation scenarios, about 20
systems containing a number of facilities would have to be
constructed and licensed. In addition, and perhaps more
controversial, a number of facilities that reprocess nuclear
materials, including plutonium, would have to be established and
licensed. The reprocessing of commercial spent fuel has been
institutionally and publicly unacceptable in the United States at
least since the 1970s because of perceived nuclear materials
proliferation and public-risk concerns. This policy against
reprocessing commercial fuel was reiterated by the administration as
recently as September 1993.
DOE HAS LITTLE INTEREST IN
TRANSMUTING EXISTING
RADIOACTIVE WASTE
---------------------------------------------------------- Chapter 4:4
DOE's waste management groups have not supported the funding of
transmutation research because, as discussed above, they consider it
unnecessary and uneconomical for the treatment of the existing
radioactive waste problem. DOE's Nuclear Energy Office is the only
DOE group providing any funding for transmutation research, and this
is only for the ALMR/IFR concept. This funding helps to keep the
nuclear energy group's main program--the development of a
liquid-metal fast breeder reactor--alive. The administration and
some members of the Congress tried to terminate funding for the
program for fiscal year 1994, but the Congress enacted $145 million
to support the program for the fiscal year. The administration
immediately sought to rescind much of this funding. DOE program
officials expect that obtaining future funding for the ALMR/IFR will
continue to be difficult. These officials said that without full
funding, the program will be pushed off further into the future, by
as much as several decades or, perhaps, never finished.
No office in DOE has championed any of the other transmutation
concepts, nor have they received significant funding. Some of the
concepts have obtained small amounts of discretionary funding\3
support from their respective laboratories to maintain a small
effort.
--------------------
\3 These laboratory discretionary funds are actually part of the
overall funding that a laboratory receives from DOE each year.
POSSIBLE FUTURE BENEFITS OF A
PROVEN TRANSMUTATION TECHNOLOGY
---------------------------------------------------------- Chapter 4:5
Although opinions are mixed on the feasibility and practicality of
transmuting highly radioactive defense waste and the spent fuel from
current commercial nuclear reactors, many in the nuclear field agree
that the capability to transmute waste would be an attractive design
attribute for any future generation of nuclear power plants. This
capability would allow nuclear power plants to burn much of their own
waste and thus reduce the volume of high-level waste that would need
to be buried. Eventually it might lead to down-sizing repositories,
building fewer of them, or even using nongeological ways of safely
disposing of waste. Those holding this opinion caveated their
statement with an assumption that the technical, economic, and
institutional problems to implementing radioactive waste
transmutation could eventually be overcome and the use of nuclear
power would continue and eventually expand in the United States. For
example, the manager of Argonne's IFR portion of the ALMR/IFR program
has stated publicly that development of waste transmutation
technology should be pursued only if it is believed that nuclear
power will increase in the United States.
CONCLUSIONS
---------------------------------------------------------- Chapter 4:6
If nuclear power continues to be used in the United States and if
waste transmutation could be proved technically and economically
feasible, not as much long-lived radioactive waste would be produced
if future power needs are met by using a new generation of power
producers that are designed to economically burn their own waste.
However, at this point, it appears that it may not be practical to
pursue transmutation primarily to address the existing radioactive
waste problem. A number of constraints are expected to slow or
prevent practical application. These include current funding
constraints and the high cost and long time needed to develop and
implement transmutation; the technical, institutional, and public
challenges that would need to be overcome; and, perhaps most
important of all, DOE waste managers', industry representatives', and
others' belief that transmutation is not necessary or
cost-beneficial. DOE's consideration of these constraints and the
forthcoming results of the National Research Council's study on waste
separation and transmutation may provide DOE with guidance on how and
to what extent to pursue transmutation technology.
MAJOR CONTRIBUTORS TO THIS REPORT
=========================================================== Appendix I
RESOURCES, COMMUNITY, AND
ECONOMIC DEVELOPMENT DIVISION,
WASHINGTON, D.C.
--------------------------------------------------------- Appendix I:1
Jim Wells, Associate Director
Robert E. Allen, Jr., Assistant Director
Jack H. Paul, Evaluator-in-Charge
William J. Mohan, Evaluator
GLOSSARY
============================================================ Chapter 1
ACCELERATOR
-------------------------------------------------------- Chapter 1:0.1
A device that increases the velocity and energy of charged particles,
such as electrons and protons; also referred to as a particle
accelerator. In a "linear" accelerator, particles are accelerated in
a straight path.
ACTINIDES
-------------------------------------------------------- Chapter 1:0.2
The elements with atomic numbers above 88 (actinium, element 89).
The actinide series includes uranium, atomic number 92, and all the
man-made transuranic elements. See "transuranic."
ATOM
-------------------------------------------------------- Chapter 1:0.3
A particle of matter indivisible by chemical means. The smallest
unit of a chemical element, approximately 1/100,000,000 inch in size,
consisting of a nucleus surrounded by electrons.
ATOMIC NUCLEUS
-------------------------------------------------------- Chapter 1:0.4
The central core of an atom, made up of neutrons and protons held
together by a strong nuclear force.
BREEDER REACTOR
-------------------------------------------------------- Chapter 1:0.5
A nuclear reactor that produces more fissionable fuel than it
consumes.
CRITICAL
-------------------------------------------------------- Chapter 1:0.6
Capable of sustaining a nuclear chain reaction.
DECAY HEAT
-------------------------------------------------------- Chapter 1:0.7
The heat produced by the decay of radioactive nuclides.
FAST BREEDER REACTOR
-------------------------------------------------------- Chapter 1:0.8
A fast reactor that produces more fissionable material than it
consumes. See "fast reactor."
FAST NEUTRONS
-------------------------------------------------------- Chapter 1:0.9
Neutrons with energies greater than 100,000 electron volts
(considered very high energy).
FAST REACTOR
------------------------------------------------------- Chapter 1:0.10
A reactor in which the fission chain reaction is sustained primarily
by fast neutrons. See "fast neutrons."
FISSION
------------------------------------------------------- Chapter 1:0.11
The splitting of a nucleus into two approximately equal parts, which
are nuclei of other elements, accompanied by the release of a
relatively large amount of energy and generally one or more neutrons.
Fission can occur spontaneously but usually is caused by nuclear
absorption of neutrons.
FISSION PRODUCTS
------------------------------------------------------- Chapter 1:0.12
The radioactive fragments (by-products) formed by nuclear fission in
a reactor--the "ash" of nuclear power production. Technetium and
iodine radioisotopes are examples of fission products found in spent
fuel.
FUEL
------------------------------------------------------- Chapter 1:0.13
Fissionable material used or usable to produce energy in a reactor.
FUEL CYCLE
------------------------------------------------------- Chapter 1:0.14
The series of steps involved in supplying fuel for nuclear power
reactors. It includes mining, refining, enrichment, original
fabrication of fuel elements, their use in a reactor, chemical
processing to recover fissionable material remaining in spent fuel,
enrichment of the fuel material, and refabrication into new fuel
elements. Waste disposal is a final step.
FUEL REPROCESSING
------------------------------------------------------- Chapter 1:0.15
The chemical or metallurgical treatment of spent (used) reactor fuel
to recover the unused fissionable material, separating it from
radioactive waste. The fuel elements are chopped up and chemically
dissolved. Plutonium and uranium and possibly other fissionable
elements are then separated out for further use.
HALF-LIFE
------------------------------------------------------- Chapter 1:0.16
The period of time required for the radioactivity of a substance to
drop to half its original value; the time that it takes for half of
the atoms of a radioactive substance to decay. Measured half-lives
vary from millionths of a second to billions of years.
ISOTOPE
------------------------------------------------------- Chapter 1:0.17
An isotope of an element is one of two or more forms of the element
that differ in their atomic weights (number of neutrons in the
nucleus of the element).
LIGHT WATER
------------------------------------------------------- Chapter 1:0.18
Ordinary water.
LINEAR ACCELERATOR
------------------------------------------------------- Chapter 1:0.19
A long straight tube (or series of tubes) in which charged particles
(ordinarily electrons or protons) gain in energy by action of
oscillating electromagnetic fields.
MINOR ACTINIDES
------------------------------------------------------- Chapter 1:0.20
The transuranic elements minus plutonium. Usually this term is used
to refer to neptunium, americium, and curium. Some also refer to
these as the "minor" transuranics. Plutonium is the dominant
transuranic, but these minor transuranics contribute comparable
radioactivity in spent fuel.
NEUTRON
------------------------------------------------------- Chapter 1:0.21
An uncharged particle with a mass slightly greater than that of a
proton. The neutron is a strongly interacting particle and a
constituent of all atomic nuclei except hydrogen.
NUCLEAR REACTION
------------------------------------------------------- Chapter 1:0.22
A reaction involving a change in an atomic nucleus, such as fission,
fusion, neutron capture, or radioactive decay, as distinct from a
chemical reaction, which is limited to changes in the electron
structure surrounding the nucleus.
NUCLEAR REACTOR
------------------------------------------------------- Chapter 1:0.23
A device in which a fission chain reaction can be initiated,
maintained, and controlled. Its essential component is a core
containing fissionable fuel. It is sometimes called an atomic
"furnace"; it is the basic machine of nuclear energy.
NUCLEUS
------------------------------------------------------- Chapter 1:0.24
The central core of an atom, made up of neutrons and protons held
together by nuclear force.
NUCLIDE
------------------------------------------------------- Chapter 1:0.25
Any species of atom that exists for a measureable length of time.
The term is used synonymously with isotope. A radionuclide is a
radioactive nuclide.
PROTON
------------------------------------------------------- Chapter 1:0.26
A particle with a single positive unit of electrical charge and a
mass that is approximately 1,840 times that of the electron. It is
the nucleus of the hydrogen atom and a constituent of all atomic
nuclei.
PUREX PROCESS
------------------------------------------------------- Chapter 1:0.27
The plutonium and uranium extraction (PUREX) process is an aqueous
process used in several foreign commercial and U.S. defense programs
for separating out elements in spent nuclear fuel.
PYROPROCESSING
------------------------------------------------------- Chapter 1:0.28
Nonaqueous processing carried out at high temperatures. An example
of this is the relatively new technology being developed for
reprocessing spent fuel mainly from liquid-metal reactors that would
use a metal alloy fuel, as opposed to the oxide-based fuel that is
used in current commercial reactors. It consists of three steps:
electrorefining to separate the useful fuel materials (including
actinides) from the radioactive fission products; cathode processing,
which further purifies the metal product of the electrorefining; and
injection casting to refabricate the reclaimed useful fuel materials
into new fuel rods.
RADIOACTIVE
------------------------------------------------------- Chapter 1:0.29
Referring to the spontaneous transformation of one atomic nucleus
into a different nucleus or into different energy states of the same
nucleus.
RADIOACTIVE DECAY
------------------------------------------------------- Chapter 1:0.30
The spontaneous transformation of one atom into a different atom or
into a different energy state of the same atom. The process results
in a decrease, with time, of the original number of radioactive atoms
in a sample.
RADIOACTIVE WASTE
------------------------------------------------------- Chapter 1:0.31
Equipment and materials (from nuclear operations) which are
radioactive and for which there is no further use. The waste is
generally classified as high-level, low-level, or transuranic,
depending on the composition and intensity of the radioactive
constituents.
RADIOISOTOPE
------------------------------------------------------- Chapter 1:0.32
A radioactive isotope. An unstable isotope of an element that decays
spontaneously, emitting radiation. Radioisotopes contained in the
spent fuel resulting from the production of nuclear power generally
fall into two categories: fission products and transuranic elements
(known as transuranics, actinides, or TRU), and activation products
produced by neutron absorption in structural materials in the spent
fuel.
RECYCLING
------------------------------------------------------- Chapter 1:0.33
The reuse of fissionable material, after it has been recovered by
chemical processing from spent reactor fuel.
SPENT FUEL
------------------------------------------------------- Chapter 1:0.34
Nuclear reactor fuel that has been irradiated (used) to the extent
that it can no longer effectively sustain a chain reaction and
therefore has been removed from the reactor for disposal. This
irradiated fuel contains fission products, uranium, and transuranic
isotopes.
SUBCRITICAL
------------------------------------------------------- Chapter 1:0.35
Not capable of sustaining a nuclear chain reaction, but involving
some degree of multiplication of neutrons.
TARGET
------------------------------------------------------- Chapter 1:0.36
Material subjected to particle bombardment (as in an accelerator) in
order to induce a nuclear reaction.
THERMAL NEUTRONS
------------------------------------------------------- Chapter 1:0.37
Low-energy neutrons that have come to thermal equilibrium with the
material in which they are moving. Most have energies of less than a
few tenths of an electron volt. Current commercial reactors use
thermal neutrons.
TRANSMUTATION
------------------------------------------------------- Chapter 1:0.38
The transformation (change) of one element into another by a nuclear
reaction or series of reactions.
TRANSURANIC
------------------------------------------------------- Chapter 1:0.39
An element above uranium in the Periodic Table of elements--that is,
one that has an atomic number greater than 92. All transuranics are
produced artificially (during a man-made nuclear reaction) and are
radioactive. They are neptunium, plutonium, americium, curium,
berkelium, californium, einsteinium, fermium, mendelevium, nobelium,
and lawrencium.
TRUEX
------------------------------------------------------- Chapter 1:0.40
A chemical solvent process under development to extract transuranics
from high-level waste.
WASTE SEPARATION
------------------------------------------------------- Chapter 1:0.41
The dividing of waste into constituents by type (for example,
high-level, low-level) and/or by isotope (for example, separating out
plutonium and uranium). The waste may be separated by a chemical
solvent process such as PUREX or by any of a number of other chemical
or physical processes.