DISPOSITION OF EXCESS WEAPON PLUTONIUM AND URANIUM
September 8, 1997
4th Pugwash Workshop on The Future of the Nuclear Weapons
Complexes of the U.S. and Russia
Moscow and Snezhinsk, 9-13 September 1997
DISPOSITION OF EXCESS WEAPON PLUTONIUM AND URANIUM
Richard L. Garwin
ABSTRACT. Numerous papers have laid the groundwork for the
disposition of excess weapon plutonium and uranium, most
recently the Final Report of U.S.-Russian Independent
Scientific Commission on Disposition of Excess Weapons
Plutonium" (June 1, 1997). The present paper summarizes
those agreed recommendations, adds some further remarks by
the author, and comments on certain aspects of the U.S.
program. Neither the spending nor the organizational
activity is yet appropriate to the clear and present danger
posed by excess material suitable for fabricating tens of
thousands of nuclear warheads, which poses a danger of
proliferation or rearmament until it is irrevocably
separated from the military sector and ultimately disposed
of so as to meet the Spent Fuel Standard so that it poses
little additional risk to that presented by the much larger
amount of plutonium present in the spent fuel from civil
power plants worldwide.
INTRODUCTION.
Numerous reports and analysis have evaluated the clear and
present danger posed by the excess plutonium and high
enriched uranium (HEU) from the tens of thousands of nuclear
weapons now surplus to the START I, START II, and the
hoped-for START III agreements between the U.S. and the
former Soviet Union and the U.S. and Russia. Among them are
three Committee reports of which I was an author(1) Thus far
in the United States many thousands of weapons are held in
reserve, since the START agreements limit only deployed
strategic weapons, but some 1500 weapons per year have been
dismantled over the last six years or so, so that the
components from many thousands of weapons exist in storage.
The situation in Russia is believed to be similar, although
Russia has made no formal declaration in this matter. In
the United States the HEU parts are shipped to Oak Ridge,
where they are stored until they are eventually to be
blended down with natural or low enriched uranium (LEU) to
provide fuel for civil reactors.
The plutonium is contained in sealed "pits", roughly
spherical hollow metal assemblies, each with a "fill tube"
projecting from it, that is used to inject a mixture of
deuterium and tritium gas just before the nuclear explosion.
The pits are placed in durable storage containers and
stored, many of them in "igloos" in a protected area of the
Pantex plant at Amarillo, Texas. As is familiar to all
readers, the United States has initiated a program to
dispose of this excess weapons usable material. The former
Secretary of Energy has declared total U.S. production of
plutonium over the years at just under 100 tons, and the
disposition program is committed to burn part of the excess
weapon plutonium as mixed-oxide fuel (MOX) in commercial
power reactors, while disposing of another part of the
excess with a protective barrier of highly radioactive
fission products, in the form of vitrified glass logs in
stainless steel containers that will be placed in the Yucca
Mountain repository now being prepared to receive also spent
commercial reactor fuel.
The paper summarizes the existing status in the United
States and some problems.
CURRENT SITUATION.
The June 1 Final Report of the U.S.-Russian Independent
Scientific Commission(2) makes unanimous recommendations in
each of the categories:
A. Overall Approach
A.1 The U.S. and Russian governments, with support and
cooperation from the international community, should take
additional steps - beyond those already underway - to more
rapidly reduce the security risks posed by excess weapons
plutonium.
A.2 Two approaches to reducing the weapons-usability of the
excess plutonium to the spent-fuel standard - using the
plutonium in mixed oxide (MOX) fuel for burning once-through
in currently operating nuclear power reactors, and
vitrifying the plutonium together with fission products in
glass logs of the type planned for use in immobilizing
high-level radioactive wastes from the defense- production
complex - should both be brought to the point of operability
at large-scale as rapidly as practicable in both countries.
A.3 The highest standards of materials protection, control,
and accounting - as appropriate to the threat of theft or
diversion - should be applied to excess weapons plutonium at
all storage, processing, and transport steps until it
reaches the spent-fuel standard. The same is true of HEU
until it has been blended down to enrichment levels too low
for use in nuclear explosives.
A.4 Increased transparency about the inventories of nuclear
warheads and nuclear-explosive materials possessed by the
United States and Russia, and about the steps being taken to
reduce these inventories, should be pursued.
A.5 The U.S. and Russian programs of warhead dismantlement
and management and disposition of the associated
nuclear-explosive materials should continue to proceed in
parallel, seeking to complete comparable steps in this
process on comparable time scales, and to reach equivalent
remaining quantities of plutonium and HEU in the two
military stockpiles.
A.6 Increased funding should be provided on an urgent basis
for analysis, development, testing, licensing, and
deployment of the systems for management and disposition of
weapons plutonium and HEU as described here.
B. Storage, Protection, Control, and Accounting
B.1 The U.S. and Russian governments should continue to
cooperate in providing secure storage for fissile materials
removed from nuclear weapons, and in improving security and
accounting for all separated plutonium and HEU.
B.2 The United States and Russia should move quickly to
implement and expand on the reciprocal information exchanges
and mutual inspections related to nuclear stockpiles that
have been agreed to in principle, to help ensure the
transparency and irreversibility of nuclear arms reductions.
B.3 As the P-8 leaders agreed at the Moscow Nuclear Safety
and Security Summit in April of 1996, excess plutonium and
HEU should be placed under international safeguards as
quickly as practicable.
B.4 Russia, like the United States, should begin declaring
specific quantities of nuclear material to be excess to its
military needs.
B.5 Both countries should seek to make additional tens of
tons of material eligible for International Atomic Energy
Agency (IAEA) safeguards during 1997.
C. Disposition of Excess Plutonium
C.1 The United States and Russia should move promptly to
select, authorize, fund, and bring to the point of
operability at the necessary scale the specific variants of
both the MOX/current-reactor approach and the
vitrification-with-wastes approach that will be used for
disposition of excess weapons plutonium to the spent-fuel
standard in each country.
C.2 The two governments should establish appropriate
managerial structures - one in each country, as well as an
international framework for managing joint activities - to
be responsible to the Presidents for carrying out this work
to specified endpoints on a specified timetable.
C.3 The United States and Russia should expedite and expand
their technical cooperation focused on developing, testing,
and demonstrating rapidly implementable and cost-effective
means for converting pits to oxide suitable for MOX-fuel
fabrication, and for processing other plutonium forms to
prepare them for disposition.
C.4 The United States and Russia, along with other
countries with relevant experience, should expand their
technical cooperation related to analyzing, testing,
licensing, and demonstrating the fabrication of MOX fuel
made from weapons plutonium and the use of this fuel in
currently operating reactors.
C.5 The United States, Russia, and the international
community should begin now to address the largest obstacle
to progress on plutonium disposition beyond interim storage,
which is financing and constructing adequate capacity in the
two countries for processing plutonium pits into plutonium
oxide and for fabricating plutonium and uranium oxides into
MOX fuel.
C.6 In order to facilitate rapid initiation of plutonium
disposition in MOX fuel, contracts should be sought with
existing European MOX fabrication plants to produce initial
batches of weapon-plutonium MOX for U.S. and Russian
reactors, while MOX fabrication facilities in the United
States and Russia are being prepared.
C.7 Because of the urgency of proceeding with disposition
to the spent-fuel standard, both the United States and
Russia should begin their programs for this purpose using
currently operating reactors.
C.8 Work should be continued to prepare for the possibility
of weapon-plutonium/MOX use beyond the U.S. and Russian
reactors now planned for the first phase of the
reactor-disposition approach and/or beyond the partial MOX
core loadings likely to be used initially in these reactors.
C.9 The United States and Russia, along with other
countries with relevant experience, should expand their
technical cooperation related to analyzing, testing,
licensing, and demonstrating vitrification of plutonium with
high-level radioactive wastes.
C.10 The nuclear-regulatory agencies in both countries
should be directed - and funded - to develop the procedures
to review and license promptly the MOX fuel fabrication
plants, reactors using MOX fuels, and plutonium-with-waste
vitrification plants needed to implement weapons-plutonium
disposition.
C.11 The United States and Russia should move as quickly as
practicable to end additional production of weapons
plutonium, including providing the necessary financing to
complete their cooperative project to convert the cores of
the plutonium production reactors at Seversk (Tomsk-7) and
Zeleznogorsk (Krasnoyarsk-26).
C.12 The United States and Russia should begin discussions
with the goal of reaching a formal agreement governing
plutonium disposition.
Of course, I agree with this Final report, which was the
result of considerable joint effort among the ten members
and their Executive Secretaries D.F. Tsourikov and
M.G. Bunn.
In addition, I had occasion on July 24, 1997, to address the
Secretary of Energy and the Department of Energy(3) and used
my three minutes available as follows:
Thank you, Mr. Secretary. The Enrico Fermi Award
celebrates past achievements, but we need also to move
ahead with the opportunities of the post-Cold-War
world.
Here are three:
First, in January the U.S. Government announced its
decision to dispose of its excess bomb plutonium from
stocks and dismantled nuclear weapons BOTH by
incorporating a portion of it with the radioactive
wastes being converted into durable glass for
underground storage AND by using a portion of it for
fuel in U.S. power reactors. As one of the five U.S.
members of an Independent Scientific Commission created
by Presidents Clinton and Yeltsin, I urge that we move
without delay to carry out this decision and thus
reduce the serious hazard that this material,
particularly Russian material, will end up in nuclear
weapons in the hands of terrorists or of nations
thirsting for nuclear weaponry.
Second, in carrying out its obligation to maintain U.S.
nuclear weapons reliable, safe, and secure, the
Department of Energy needs every few years or every
decade to refresh the supply of tritium in each nuclear
weapon. Because active-duty U.S. nuclear weapons have
been reduced in number over this decade and the next
much more rapidly than the loss of tritium by
radioactive decay (50% every 12 years), there has been
and until the year 2010 or so there will be more than
enough tritium available for this purpose without the
manufacture of new tritium. DOE has programs to
develop a powerful particle accelerator to recreate
tritium from its helium ashes, and one to produce
tritium in power reactors. Billions of dollars would
be saved by choosing the reactor route, and that should
be perfected and held in reserve. But the opportunity
is really the purchase of tritium from Russia, which I
understand is ready to sell it at a small fraction of
the cost to the U.S. of even reactor production. No
impairment of U.S. security can result, if tritium is
acquired 5 years before it is needed; if the supply is
cut off, there is thus time to begin domestic
production. And if Russian and U.S. nuclear weapons
are reduced from the 10,000 we plan to hold under
current agreements, we will save not only major capital
expenditure but also the cost of tritium purchase.
Third, the U.S. is purchasing 500 tons of Russian bomb
uranium ("high enriched uranium"--HEU) over 20 years,
blended down as low-enriched power reactor fuel useless
for nuclear weapons; deliveries began about two years
ago. The HEU awaiting delivery is directly usable to
make some 20,000 nuclear weapons. We could eliminate
this hazard of nuclear proliferation to terrorists or
weapon-thirsty states by paying Russia to blend all
this HEU now to 20% U-235 (also useless for nuclear
weapons), and to receive a credit for this payment when
we take delivery of the reactor fuel further blended
down to 4.4% U-235.
I know that many of my colleagues in the scientific,
technical, and foreign policy communities are ready to
help realize these opportunities.
The full text of the Final Report of the U.S.-Russian
Independent Commission is available at this meeting, so I
now comment on the situation in the United States.
There is no entrenched bureaucracy that is going to benefit
by urgent activity on this disposition program, no matter
how important it is to the security of the United States or
to the world. Thus the Secretary of Energy and the
President and the Vice President must take the lead in
creating such a bureaucracy and in giving it a kick start.
In general there are problems associated with both options,
as envisioned by the CISAC panel in its report, and that is
the reason for advocating that both approaches go ahead
rapidly in both countries.
THE MOX ROUTE. The Department of Energy has a substantial
component in its leadership that is no great supporter of
nuclear power in any form, and certainly opposes
reprocessing of commercial spent fuel. I am, myself,
totally opposed to reprocessing of spent lightwater reaction
(LWR) fuel in the United States or the reprocessing of U.S.
LWR fuel anywhere in the world, and the reasons are those of
the famous Ford-MITRE study.(4) It is just not economical,
and so far as I can see from my review of the situation in
recent years, including a visit to the well-run COGEMA plant
at La Hague, the processing adds additional potential
problems for radiation leakage, without reducing
significantly the problems of storage and of geologic
disposal. Some equate the burning of excess weapon
plutonium in commercial reactors with "closing the cycle"
for commercial reactor fuel, which RESULTS in the burning of
MOX in reactors.
But the two are very different: In the one case one is
disposing of a hazard, while in the other one is creating a
hazard and then partially disposing of it. Perhaps spurred by
outside critics, DOE seems inclined to require a further
Record of Decision (ROD) before proceeding, whereas it is
the view of the five U.S. members of the Commission that no
such additional ROD is required and that the decision has
already been made and all that remains to be done is to
implement it and to choose the particular contractors and
reactors which will handle the MOX. Of course, as indicated
by the recommendations cited above, the U.S. still needs to
fabricate weapon plutonium into MOX, and a suitable plant
for this processing (including the removal of gallium) needs
to be built. So that is the problem on the MOX side.
THE VITRIFICATION ROUTE. The 1994 and 1995 CISAC reports
envisaged largely the feeding of plutonium oxide into the
stream of fission product entering a melter at the Savannah
River Plant (SRP) in the United States, and loading
about 1% Pu by weight into the vitrified glass in this way.
The normal glass appears to hold at least 7%, so there
should be no problem with this 1%. The SRP has begun now
the vitrification of high-level fission product waste
leftover from the separation of that very same weapon
plutonium, and they use now a very large melter instead of
the bench-size melters in use at COGEMA. I believe that
this was a strategic error, and I would hold this opinion
whether or not one needed to dispose of excess weapon
plutonium. The development cost for such a large melter is
substantially greater than the cost for small melters, and
one has far less flexibility in improving, changing, and the
like.
For the disposition of weapon plutonium, the large melter
poses a particular problem, since the tens of kilograms of
plutonium that would be present in the melter at any one
time must be guaranteed not to segregate and cause
criticality problems. So SRP has proposed the "can in
canister" approach, in which plutonium is vitrified without
fission products and placed in cans that occupy 10-30% of
the volume of the ultimate canister, supported on a
structure inside the canister. The vitrified fission
products are then poured around the structure. Of course,
if the same amount of plutonium (say 20 kg per canister) is
to be loaded into cans that fill 10% of the volume, the
plutonium concentration in the cans must be 10%, so a
different glass must be used. In fact, some argue that
ceramic rather than glass is a better solution for the
material inside the can, and the Department of Energy is
reputed to be ready to announce a decision in October 1997
to use such a ceramic instead of glass. But the plutonium
in the ceramic or in the glass is not intimately mixed with
fission products, and so there is a substantial portion of
the cycle where the plutonium is not protected against
approach or theft, and even after it is disposed, it may be
possible by the use of explosives to separate these cans,
although that would be a rather messy procedure.
I criticize DOE and Savannah River Plant in this because we
have lost years on this program because of the initial
decision to use a large melter, although there is no reason
to believe that a ceramic approach (much like that used in
providing MOX fuel for an LWR or a breeder reactor) would be
inadequate, because it is much like the process involved in
producing MOX fuel for a LWR or for a fast reactor.
Nevertheless, a production line needs to be set up to handle
all of the plutonium and to fabricate such glass or ceramic,
and this line will need to handle all of the plutonium and
10% or 30% of the mass of the canister fill.
THE DUAL-TRACK APPROACH IN RUSSIA
In many discussions of the Independent Scientific Commission,
CISAC, and other groups, Russian representatives have
expressed a strong and principled position in favor of
burning excess W-Pu as MOX (in this way releasing some of the
energy stored in the plutonium); they have scorned the idea
that excess W-Pu is a "waste" because it costs more to burn
as fuel in reactors than the cost of fresh enriched uranium
fuel. Nevertheless, the Spent Fuel Standard has been adopted
by the Russian side, and vitrification experiments are indeed
going forward, so that both the U.S. and Russia will benefit
from the research on both sides.
----------------
1 Panofsky, W.K.H., Chair, "Management and Disposition of
Excess Weapons Plutonium," Report of the National
Academy of Sciences, Committee on International Security
and Arms Control, January 1994;
Holdren, J.P., Chair, "Management and Disposition of
Excess Weapons Plutonium: Reactor-Related Options,"
Report of the National Academy of Sciences, Committee on
International Security and Arms Control, Panel on
Reactor-Related Options for Disposition of Excess
Weapons Plutonium, July 1995; and
Holdren, J.P. and Velikhov, E.P. (Co-Chairs), "Final
Report of U.S.-Russian Independent Scientific Commission
on Disposition of Excess Weapons Plutonium" by
J.P. Holdren (Co-Chair), J. Ahearne, R.L. Garwin,
W.K.H. Panofsky, J.J. Taylor, and E.P. Velikhov
(Co-Chair), A.A. Makarov, F.M. Mitenkov,
N.N. Ponomarev-Stepnoi, F.G. Reshetnikov, 1 June 1997.
The first two are available on the Web at
http://www.nap.edu, and the third will be available at
http://www.fas.org/rlg and copies are available at this
Pugwash Workshop.
2 E.P. Velikhov (Co-Chair); A.A. Makarov; F.M. Mitenkov;
N.N. Ponomarev-Stepnoi; F.G. Reshetnikov. and
J.P. Holdren (Co-Chair); J. Ahearne; R.L. Garwin;
W.K.H. Panofsky; J.J. Taylor.
3 On receipt of the Enrico Fermi Award.
4 Keeny, S.M., Chairman, NUCLEAR POWER ISSUES AND CHOICES,
sponsored by the Ford Foundation-MITRE Corporation,
Ballinger Publishing Co, March 1977.
RLG:jah:W251DEWP:090897DEWP