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.




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