Plutonium: the international scene*

Since the pace at which a country s acquisition ofnuclear weapons depends upon the availability ofweapon-usable fissile materials, it is not enough toeliminate existing weapons: we must also have a rationalpolicy governing the issue of plutonium, both militaryand civil. The ultimate objective must be the completeabolition of nuclear weapons.

Trinity, the first nuclear device, tested at Alamogordo,New Mexico on July 16, 1945, had a plutonium core of6.2 kg, a sizable fraction of the entire world inventory ofseparated plutonium. Over the next 50 years the UnitedStates government produced and separated about 103 t ofplutonium. The current US inventory is about 98 t. Ofthis amount about 84 t is weapon-grade plutonium thatwas produced for weapons. With this plutonium and amuch larger stock of highly enriched uranium (HEU), theUnited States has constructed over this 50-year periodsome 70,000 nuclear weapons, with the plutonium andHEU being used several times in different generations ofweapons. The US operational nuclear weapon stockpilepeaked in 1967 at about 32,500 warheads and is about10,000 warheads today; the US currently plans to retainsome 7,400 warheads after START 11. Of the wp,apoD-grade plutonium, about 64 t is in 21,500 plutonium pits,including those in weapons and those stored at Pantex.1Each pit contains, on average, 3 kg of plutonium.

Soviet/Russian warhead plutonium production, whichbegan in 1948, probably amounts to some 150--170 t,2,3of which an estimated 115-130 t was actually fabricatedinto weapon components (the rest is assumed to be inproduction scrap, solutions, and residues).t The total(active plus reserve) Russian nuclear weapon stockpileapparently peaked in 1985 at about 45,000 warheads,4

but some of these weapons may have had HEU cores, orcomposite Pu-HEU cores rather than pure plutonium pits.Thus, even if it is conservatively assumed that 10,000 ofthese (primarily older) weapons used exclusively HEU

*This paper was first presented at the Royal Society, PugwashConferences on Science and World Affairs, Public Discussion Meeting,Plutonium management and control, London, 8 December 1995.

cores, the average plutonium content of the remaining35,000 Russian weapons stilI does not exceed 4 kg.4:

This estimate is consistent with external gamma andneutron measurements made in 1979 of a Soviet navalcruise missile warhead in its launch tube, which indicateda plutonium mass of 3-6 kg.5 The Russian arsenal isprobably at about 25,000 warheads today, and Russia willsurely retain a START 11inventory comparable to that ofthe United States.

With the much smaller contributions from the othernuclear powers, totalling about 12 t, the global stocks ofmilitary plutonium today total about 245-265 t, or about40,000 times the amount in the Trinity device.6

The amount of plutonium in civil reactor programme isnot precisely known. A typical 1000 MWe light-waterreactor produces about 200 kg of reactor-grade plu-tonium per year. There are about 432 operating nuclearpower plants in the world with a combined capacity ofabout 340 000 MWe. The nuclear spent fuel dischargedannually from these plants contains some 60-70 t ofreactor-grade plutonium. Most of this spent fuel has notbeen processed, and the cumulative amount of unsep-arated plutonium today is in the order of 1000 t. A fewcountries, most notably the UK, France, Japan andRussia, have active programmes of commercial spent fuelprocessing. BNFI:s new thermal oxide reprocessing plant(THORP) has II de!;ign M'!,:1r'ity "f t "J\O t heavy mp,taJper year (tHM/y). Operating at a nominal 60% capacityfactor, THORP is capable of separating about 6--7 t ofreactor-grade plutonium per year. On a global scale theability to separate plutonium has greatly exceeded theability to turn the plutonium into fresh reactor fuel. As aconsequence the global surplus of plutonium separatedfrom civil fuel exceeds 150 t and should exceed thatseparated for weapons by the year 2000. At the end ofMarch 1994 the British Government announced that theinventory of civil plutonium in Britain amounted to 40 t.7

tThe fraction of pipeline materials, i.e. solutions, scrap, and residues, inthe Russian weapon programme is assumed to be comparable to that inthe US weapon programme.IThe apparent preference for 3--4 kilograms of plutonium per weapon,rather than some lower number, can be explained by the fact that thisamount of material affords the optimal yield-to-weight ratio for thewarhead.

How far to go and what steps to take?South Africa is the only weapon state that has

dismantled its nuclear arsenal - a total of six atomicbombs. The British Pugwash Group has presented thecase for the United Kingdom to relinquish its nuclearweapons arsenal of about 250 nuclear weapons.8 Thereare many British policymakers who may agree to deeperreduction in the nuclear arsenals but who are notprepared to see their country relinquish its status as anuclear weapon state. Even they should be prepared toundertake now any number of beneficial steps on the roadto disarmament, such as placing all or most of Britain'sSLBM warheads in inactive land-based storage. At thevery least all should agree that every nation should takewhatever steps are necessary now to insure that the roadto abolition of nuclear weapons will not be blocked in thefuture. Today, at a minimum, Britain should adopt orsupport the steps identified in Table I:

(a) Further deep reductions in the deployed arsenals ofall nuclear-weapon states, declared and undeclared

Neither the US Senate, nor the Russian Duma, haveratified START II. Instead of negotiating further reduc-tions, Pentagon plans, as set forth in the Nuclear PostureReview, call for retention of a hedge arsenal of some2500 strategic warheads and almost 1000 non-strategicwarheads in addition to the 3500 strategic warheads, thenumber allowed under START II. Russia has been silentwith regard to the number of warheads it plans to retain.The UK should playa more forceful role in encouragingthe US and Russia to implement START II and initiatefurther reductions. At a minimum, the UK should removeall nuclear warheads from alert status and place them instorage.

(b) Declarations, data exchanges, and cooperativeverification measures to confirm the progressiveelimination of both operational and reserve nuclearweapon stockpiles, including the permanent disassemblyof nuclear warheads and bombs, the destruction of non-fissile components, and the status offissile materialcomponents withdrawn from weapons

Last December the US government finally agreed toinitiate an exchange of nuclear weapon and fissilematerial inventory data with the Russians. This efforthas been stalled for the past ten months due to Russia'sfailure to conclude an Agreement for Cooperation with

the United States that is legally required before the datacan be swapped. Both sides could have simplydeclassified the data and made it public, but Russia stillfears such gestures to democracy. The UK, which hasbeen silent about the size of its arsenal and fissilematerial inventories, should make a public declarationregarding its nuclear weapon and fissile materialinventories and encourage the other nucle.l'lf.weaponstates to follow suit.

(c) Secure storage of all plutonium and HEUcomponents withdrawn from weapons under bilateral orfive-power verification pending implementation ofarrangements for conversion/dilution to reactor jitel ordirect disposal as vitrified waste

The US has chosen the 'spent fuel standard' as thecriterion for the safe disposition of its excess plutonium,meaning that plutonium from weapons should be madeas difficult to retrieve as the plutonium currently stored asspent civil reactor fuel. To meet this standard the UnitedStates may fabricate some of the excess plutonium intomixed-oxide (MOX) fuel and burn it in reactors on aonce-through basis. The remainder of the excessplutonium likely will be mixed with fission productwaste and vitrified. Russia's Ministry of Atomic Energy(MINATOM) would like to use its excess plutonium tofuel new breeder reactors, but does not possess thefinancial means to implement this proposal. Meanwhile,Russian weapon-usable fissile materials are stored underinadequate physical security and material control andaccounting. The British are playing a counterproductiverole. While the United States is trying to convertplutonium into spent fuel, the UK is busily removingplutonium from spent fuel much faster than the separatedplutonium can be burned as MOX fuel.

(d) Application in the weapon states of InternationalAtomic Energy Agency (lAEA) or comparable.multilateral safe~ards to all.fis.~ile material inventorif!Snot stored in weapon-component form, and to allfacilities with the capacity to use, produce, separate,enrich, or otherwise process fissile material

The nuclear-weapon states, including the UK, haverefused to research, develop, and demonstrate (RD&D),much less implement, a safeguards programme for theweapon states; and the US and Russia have not initiatedsuch an RD&D effort even on a bilateral basis.

Step I Further deep reductions in the deployed arsenals of all nuclear-weapon states, declared and wtdeclared.Step 2 Comprehensive declarations, data exchanges, and cooperative verification measures to confirm the progressive

elimination of nuclear weapons and the status of removed fissile materials.Step 3 Secure verified interim storage of all plutonium and HEU components withdrawn from weapons.Step 4 Application of multilateral safeguards to all fissile material inventories not stored in weapon-component form, and

to all facilities with the capacity to use, produce, separate, enrich, or otherwise process fissile material.Step 5 A global, verified cut-off in the production of fissile materials for weapon purposes.Step 6 Capping and drawing down the world inventories of weapon-usable fissile materials; including a moratorium on

programmes for the civil production and use of separated plutonium and HEU.

(e) A global. verified cut-off in the production offissilematerials for weapons purposes

Negotiations for a fissile material cut-off in the CD aregoing nowhere, primarily due to opposition (Pakistan) ornon-participation (Israel) by the threshold states.

(f) Capping and drawing down the world inventories ofweapon-usable fissile materials, including a moratoriumon programmes for the civil production and use ofseparated plutonium and HEU

The UK. France, Japan, and Russia all continue toseparate weapon-usable plutonium faster than it can beabsorbed in the commercial fuel market. It is perhapshere that the UK could play the most effective role.

The appropriate role for the UK to play with respect tothis last step is at least as controversial as the issue ofwhether the UK should retain its status as a nuclear-weapon state. Whether the aim is the abolition of allnuclear weapons, or only the protection of that option forthe future, the UK should defer further chemicalseparation of plutonium. The use of plutonium as a civilreactor fuel should be restricted to the burning of existingstocks of plutonium from weapons and from existingseparated stocks.

Why should the British defer further commercialseparation of plutonium? Before addressing this issue, itmay be useful first to clarifY two technical issues thathave clouded the debate over this issue.

How much plutonium is needed to make anuclear weapon?

The lAEA is the UN agency responsible for ensuringthe 'timely detection' of the loss or diversion of thenuclear materials needed to make a bomb from facilitiesin non-nuclear weapon states. Based upon advice givenby nuclear-weapon states in 1967, the Agency assumedthat 8 kg was the 'threshold amount' of plutoniumneeded for a first nuclear weapon, including lossesincurred during fabrication of the device. This so-called'significantly quantity' (SQ) limit is still the Agency'sthreshold limit in use today.

An SQ of 8 kg for plutonium is consistent withassuming a 30% loss in fabrication of a nuclear weaponsimilar to the Trinity device or the Nagasaki weapon,each of which had a 6.2 kg plutonium core. As indicatedby Fig. I, this IAEA criterion is technically indefensible.Even using vintage 1945 technology, 8 kg is absurdlylarge. Had the 6.2 kg plutonium core of the Nagasakiweapon been replaced with a 3 kg plutonium core, theyield of this weapon still would have exceeded I letwithno other changes in the design. During the Ranger seriesof tests in 1951, the US used an even smaller quantity ofplutonium to achieve a 1 let yield - utilizing the Mark 4bomb design, which incorporated the principle oflevitation (now declassified) which was first tested bythe United States in the 1948 Sandstone series of tests.

j;2 10i:iQ)

>=

0.1o 3 4 5

Pu mass: kg

1--Low tech ••• - - Medium tech - High tech

Fig. 1. Yield against Pu mass (as ajUnction of technicalcapability)

The UK has now revealed that it used a 2 kg plutoniumcore to obtain a yield of 3 let in its eighth test, conductedon October 11,1956. As can be deduced from Fig. 1, theboosted primaries of some modem US warheadsapparently use as little as 2 kg of plutonium compressedby only a few tens of kg of HEll. And lastly, the Russiansannounced that the warhead left at the Semipalatinsk testsite and destroyed on May 31, 1995 contained about 1 kgof plutonium and had a design yield of 0.3 let. Nuclearweapons with yields exceeding 1 let can be made with aslittle as 1 kg of weapon-grade plutonium. The primariesof several thermonuclear warheads in the US nucleararsenal are believed to contain no more than about 2 kgof weapon-grade plutonium.

Can efficient nuclear weapons beconstructed with reactor-grade plutonium?

The curves in Fig. I apply to weapon-grade plutoniumwhere the Pu-240 content is less than 7%. Most of theplutonium in the civil sectoris reactor-grade With aPu-240 content in the range of 20-35%.

Plutonium with a high Pu-240 content is less desirablefor weapons purposes than weapon-grade plutonium forfour reasons:

(a) it has a larger critical mass(b) it presents a greater radiation hazard to workers and

weaponeers(c) it give off more thermal energy (heat) as a

consequence of radioactive decay of the shorter-livedplutonium isotopes

(d) it has a greater rate of spontaneous fissions due to thehigher concentration of Pu-240.

Regardless of its Pu-240 content, the critical mass ofreactor-grade plutonium falls between that of weapon-grade plutonium and HEU. From the standpoint ofcritical mass, reactor-grade plutonium is preferred overHEU, a quite respectable weapon-usable material. The

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added radiation and thermal effects can be al1eviatedthrough shielding and design modifications.

Some advocates of civil plutonium use have arguederroneously that the higher rate of spontaneous fissionseffectively 'denatures' the explosive characteristics ofreactor-grade plutonium. For low technology weapondesigns, the neutrons generated by the high rate ofspontaneous fission of Pu-240 can increase the statisticaluncertainty of the yield by 'preinitiating' the chainreaction before the desired compression of the plutoniumcore has been achieved. In spite of this difficulty,militarily useful weapons with predictable yields in thekiloton range can be constructed based on lowtechnology designs with reactor-grade plutonium. Ac-cording to the conclusions of a recent study by theNational Academy of Sciences in the United States,based in part on a classified 1994 study by scientists atthe Lawrence Livermore National Laboratory:

'even if pre-initiation occurs at the worst possiblemoment (when the material first becomes compressedenough to sustain a chain reaction), the explosiveyield of even a relatively simple device similar to theNagasaki bomb would be on the order of one or a fewkilotons. While this yield is referred to as the ".fizzleyield", a one kiloton bomb would still have adestruction radius roughly one third that of theHiroshima weapon, making it a potentially fearsomeexplosive. Regardless of how high the concentration oftroublesome isotopes is, the yield would "ot be less.With a more sophisticated design, weapons could bebuilt with reactor-grade plutonium that would beassured of having higher yields.9By making use of various combinations of advanced

technologies, including improved implosion techniques,the use of beryllium as a neutron reflector, boosting withdeuterium and tritium, and two-stage weapon designs, itis possible to offset the problems created by the high rateof spontaneous fission of Pu-240. US Nuclear RegulatoryCommissioner, Victor Gilinsky, best summed up theissue in 1976, when he stated:

'Of course, when reactor-grade plutonium is usedthere may be a penalty in performance that isconsiderable or insignificant, depending on theweapon design. But whatever we once might havethought, we now know that even simple designs, albeitwith some uncertainty in yield, can serve as effective,highly powerful weapons - reliably in the kilotonrange. 10Assuming an advanced design were attempted using

reactor-grade (24% Pu-240) plutonium, the nominal yieldpotential of a modern 2-3 kg weapon-grade plutoniumcore could be maintained by increasing the mass of theplutonium core by about 25% - the ratio of therespective reflected critical masses. Thus, the reactor-grade equivalent of a modern 2-3 kt weapon-gradeplutonium core is about 2.5-3.75 kg.

There are two additional points that are often over-looked. First, in civil spent fuel stocks, in which most of

the fuel is high burnup, there is usual1y some low burnupfuel from which significant quantities of weapon-gradeplutonium can be extracted if the low burnup fuel isprocessed separately. Second, it is possible that advancedisotopic separation techniques, such as advanced laserisotope separation (AVLIS), may also be available to anycountry with the nuclear technology and capital sufficientto support construction (If breeders and reprocessingplants. The avaiiability of such technology would erasewhatever operational and technical deficiencies attend theuse of reactor-grade plutonium in weapons, by allowinginventories of already separated reactor-grade material tobe 'cleaned up' to weapons-grade. Indeed the US was onthe verge of constructing a large plant of this type in1989 to clean up Department of Energy stocks of fuel-grade plutonium when the Berlin Wall came down. BothFrance and the US are continuing to develop production-scale AVLIS technology for commercial uranium enrich-ment, and Israel is known to have built a small pilot-scalefacility in connection with its secret nuclear weaponsprogramme.

Why defer further commercial spent fuelreprocessing?

The above technical issues having been discussed, itremains to consider the reasons for UK deferrment offurther chemical separation of plutonium, as set outbelow (and see Table 2).

(a) Minimizing the risk of a global nuclear catastropheAs already indicated, only an extremely small quantity

of plutonium - in the order of 1-3 kg - is needed tomake a nuclear weapon with a yield of at least I kt; andplutonium of virtually any isotopic composition can beused to make a nuclear explosive, with the penalty interms of yield-to-weight or yield-to-volume dependenton the sophistication of the design.

Each tonne of reactor-grade plutonium stocks in thecivil reactor programme represents the equivalent of 130Nagasaki-type plutonium cores, or 270-400 modernnuclear weapon cores.

Limit the military potential of civil nuclear programmesThe current policies of the UK, France, Japan and

Russia of sanctioning civil spent fuel reprocessing hasresulted in a world confronted with large flows ofrecovered plutonium and plutonium stockpiles, a sig-nificant fraction in non-nuclear weapon states. BNFL, forexample, recovers 6-7 t of reactor-grade plutonium peryear at THORP by processing some 700 tHM spent fuelannually. This represents roughly 800--900 Nagasaki-type plutonium cores or 1600-2800 modem plutoniumcores annually. Japan currently has plans to build asimilar size reprocessing plant at Rokkasho.

Deployment of plutonium fast breeders would entailstaggering amounts of nuclear weapons-usable pluto-

Reason I Minimize global risk of a nuclear catastropheSmall quantities ofweapon-, fuel-, or reactor-grade plutonium can be used to make efficient, powerful nuclear

bombs as well as inefficient crude bombs and terrorist explosive devices.Reason 2 Limit the military potential of civil nuclear programmes

'Civil' plutonium programmes provide a legitimate civilian cover for any country to acquire and stockpilenuclear explosive materials, while they sustain a global technology base in chemical separation, processing, andmetallurgy that has been (and will continue to be) applied to clandestine military programmes.

Reason 3 Reduce global potential for NPT 'breakout'Nations that have 'legally' acquired a stockpile of separated plutonium, or separation facilities, under

safeguards, but then undergo political upheaval or a change in national strategy, could suddenly emerge as nationscapable of building nuclear arsenals.

Reason 4 Remove a barrier to destruction of weapon stocksNational stockpiles of separated 'civil' plutonium and operable Pu-production facilities will act as a barrier to

deeper reductions and eventual elimination of nuclear weapons held by declared and undeclared nuclear weaponstates.

Reason 5 Adequate safeguards are not possibleNational separation, recycling and breeding of plutonium on a commercial scale place an impossible burden on

the current and prospective capabilities of the IAEA safeguards system to detect promptly thefts or diversions ofPu-bomb quantities from peaceful use.

Reason 6 Ensure efficient allocation of scarce capital resources for energy developmentSeparation and use of plutonium in the civil nuclear fuel cycle is not justified by current or foreseeable energy

market conditions, which for the next several decades at least favour investments in conservation, efficiency, and arange of competing power sources, including safer, more reliable and efficient reactor technologies not requiringthe use of separated plutonium.

nium in the reactors and the supporting fuel cycle. Theplutonium inventory in a single 800--1000 MWe breederis 4-5 1. Although the net amount of plutonium producedannually in a fast breeder reactor is generally less thanthat produced in a conventional thennal power reactor ofthe same size, one-third to one-half of the fast breederreactor fuel must be removed annually for reprocessing,plutonium recovery, and remanufacture into fresh fuel.Since the fuel will be outside the reactor for 3.5-7 years,the plutonium inventory needed to support a singlecommercial-size plutonium breeder is 10--20 1. If only 10gigawatts of nations' electrical capacity were supplied bybreeders - hardly enough to justify the research anddevelopment (R&D) effort in any country even if theeconomics were otherwise favourable - the plutoniuminventory in the reactors and their supporting fuel cyclewould be in the order of 100--200 t, comparable to theweapon plutonium arsenals of the United States andRussia.

Moreover, those nations (or agencies within nations)having access to the breeder fuel cycle would not belimited to reactor-grade-Pu weapons. About one-half ofthe new plutonium created in a breeder reactor - thatwhich is bred in the blanket rods - is 'supergrade'plutonium ( < 3% Pu-240), with a Pu-240 content lowerthan that used in US and Russian weapons. Thus, anynon-weapons country that has stocks of breeder fuel hasthe capacity to produce a ready stock of low-burnupplutonium that is optimally suited for weapons; it onlyhas to segregate and reprocess the blanket assembliesseparately from the core assemblies. To maximize outputof weapon-grade material, a country could blend thesuper-grade plutonium from the breeder blanket withexisting inventories of 'fuel-grade' (> 19% Pu-240)

plutonium to create a larger quantity of 'weapon-grade'(<7% Pu-240) material.

It is noteworthy that Japan, between 1987 and 1993,acquired advanced 'centrifugal contactor' technology forseparating low-burnup plutonium from the US Depart-ment of Energy for installation in PNC's recycleequipment and test facility (RETF) at Tokai - technologythat was originally developed and tested at two USnuclear weapons production facilities: the SavannahRiver Plant and the Oak Ridge National Laboratory.

As will be discussed below, there is at present notechnically credible means of safeguarding this materialto prevent strategically significant quantities from beingdiverted for use in nuclear weapons. If development ofplutonium breeders continues in the few remainingcountries that have strong breeder R&D programmes,this will continue to legitimize breeder programmes andplutonium stockpiles in non-nuclear-weapon states thatmay use these programmes to cover the development of aweapons option. India, for example, recovered theplutonium for its first nuclear device in a reprocessingplant that was ostensibly developed as part of its nationalbreeder programme.

Consequently, remaining breeder R&D programmes, ifnot deferred altogether, should be limited to conceptualdesign efforts only, with an emphasis on advancedproliferation-resistant fuel cycles that do not requiremastery of the technology for isolating weapons-usablenuclear materials. To the extent that this goal ispolitically unattainable, sufficient plutonium has alreadybeen separated to meet the needs of R&D programmes,so at a minimum there is no requirement to continueseparating plutonium for this purpose. In this connectionit should be noted that if plutonium breeders some day

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prove to be economically competitive, and if the breederfuel cycle can be safeguarded with high confidence understringent international controls, then commercial deploy-ment could begin with cores of non-weapons-usable 20%enriched uranium. In other words, there is no need toaccumulate a stockpile of separated plutonium today toensure the possibility of deploying breeders at some pointin the future.

(c) Reduce the global potential for NPT 'breakout'Reprocessing of spent fuel and the recycling of

plutonium· into fresh fuel for reactors permit non-nuclear weapons states to justify the acquisition andstockpiling of nuclear weapons-usable material - osten-sibly for peaceful purposes. While violating their implicit(NPT) obligation not to engage in 'preparations' for'manufacture' of nuclear weapons, but without violatingany international safeguards agreements, these countriescould also secretly design, fabricate, or purchase non-nuclear-weapon components. By moving to a point ofbeing within hours of having nuclear weapons (perhapsneeding only to introduce the fissile material into theweapons) a nascent weapons state would have all of itsoptions open. Under these conditions, internationalsafeguards agreements can actually serve as a cover byconcealing the signs of critical change until it is too latefor diplomacy to reverse a decision to 'go nuclear'. In the1970s a number of countries, including Pakistan,Argentina, Brazil, South Korea, and Taiwan, soughtaccess to reprocessing technology ostensibly for peacefulpurposes. The record shows that each one of thesecountries also had a secret nuclear weapon developmentprogramme. Most recently Iraq diverted HEU from its'peaceful' research reactors with the intent of turning itinto weapons.

A non-nuclear-weapon state always has the option toshift a 'peaceful' nuclear programme, based on the once-through, or open, fuel cycle to a weapons programme, butthis would require the politically difficult decision toviolate 'full-scope' IAEA safeguards by secretly estab-lishing unsafeguarded fuel cycle facilities. Without civilreprocessing facilities and breeder reactors, countrieswishing to develop nuclear weapons capacity face veryconsiderable political obstacles and costs. Obtainingsignificant quantities of fissionable material for weaponswould require that they build one or more specializedproduction reactors and chemical separation facilitiesoutside of safeguards, using indigenous or black markettechnology.· On the other hand, acceptance of the closedfuel cycle and the plutonium breeder as a reasonablelong-term energy option provides the justification for theearly development of a reprocessing capability by anycountry. This was the route taken by India. By establish-ing a nuclear weapons option through a 'peaceful'plutonium-using nuclear electric generation programme,

·Or any other weapons material, such as highly enriched uranium oruranium-233.

current and future proliferators can obtain quick access tomassive quantities of separated weapon-usable pluto-nium.

A 'peaceful' plutonium recycle or fast breeder reactorprogramme also justifies the acquisition of a wholepanoply of specialized research facilities, training, anddata applicable to nuclear weapons design that wouldotherwise not be eagily acquired, SUl;h as:

(i) fast critical assemblies, including significant quan-tities of weapon-grade material with which toperform reactor safety and criticality experimentsin the laboratory with minimal health risk topersonnel

(ii) nuclear diagnostic instrumentation and recordingequipment

(iii) elaborate Monte Carlo neutronic codes, and data onmaterial properties at high temperatures and pres-sures, needed for controlli'n.g the same fast-neutronspectrum used in nuclear weapons

(iv) data on plutonium metallurgy and alloys forproducing plutonium fuel elements and evaluatingtheir performance

and so on. In short, a peaceful plutonium fuel cycleprogramme represents an enormous head start on anuclear weapons programme. Indeed, it represents a'legal' path to nuclear weapons potential under the NPT.

(d) Remove a barrier to the destruction of weapon stocksStockpiles of separated 'civil' plutonium will act as a

barrier to very deep reductions and eventual eliminationof nuclear weapons held by declared and undeclaredweapon states. The reality of this obstacle is immediatelyapparent when it is considered, for example, how farChina is likely to go toward eliminating its nucleararsenal if Japan accumulates a huge inventory of nuclearexplosive materials in pursuit of a civil plutoniumprogramme that has no plausible commercial justificationfor at least the next 50 years.

Likewise, how deep win be the cuts in the US nuclearweapons stockpile if Russia proceeds to large-scaledeployment of the breeder fuel cycle, with its inventoriesof hundreds of tonnes of separated plutonium andinherent capacity for creating 'super-grade' blanketmaterial; or if Russia merely continues to accumulateinventories of separated plutonium from operating 'civil'reprocessing plants while US military reprocessing plantsare shut down? The most probable answer is that asignificant fraction of the 5000 'active' and 2500 'reserve'US weapons, and 7800 stored plutonium pits, nowplanned for the year 2003, will stay right where they are.

·They could also seek international acceptance fOTthe acquisition of asafeguarded uranium enrichment plant to produce either HEU, or excessstocks of unirradiated low enriched uranium that could be rapidlyenriched to weapon-grade coincident with withdrawal from the NPT.There is now virtually zero international legitimacy for the uraniumenrichment route - the only recent exception being Russia's 'agreementin principle to negotiate' the sale of a centrifuge plant under safeguardsto Iran.

Professor Rotblat's dream of a nuclear weapon freeworld will not be realized if the UK, France, Russia andJapan continue to pursue a civil plutonium economy.

(e) On a global basis, large bulk handling facilities -reprocessing plants and plutonium fuel fabricationplants - cannot be adequately safeguarded to preventthe spread of nuclear explosive material

Adequate physical security measures are essential toprevent the theft of fissionable material, and under thepresent international safeguards system these are en-trusted to the individual nation state, which in turn maydelegate the task to private commercial entities licensedfor the purpose.

Frequent and accurate material control and accounting(MC&A) measures are essential to provide a timelydetermination of whether any significant theft or otherloss of material has occurred. This determination shouldin theory afford the international community theopportunity to undertake actions aimed at preventingany diverted, stolen, or otherwise missing material frombeing used for destructive or coercive purposes, or fromposing an unrecognized threat to the environment andhuman health. Maintaining adequate MC&A measures isthe joint responsibility of an individual nation state andinternational organizations - the IAEA and EURATOM.

Given the technical difficulty and cost of making therepeated measurements that are often necessary toprovide a high degree of assurance that all materialremains accounted for, MC&A measures are supplemen-ted by 'containment and surveillance' (C&S) techniques(mainly seals and cameras) that are intended to maintainthe integrity of measured quantities or storage areasbetween inspections. C&S techniques are also used tomonitor access to areas where direct measurementscannot be taken, or where the error in making remotemeasurements is large.

It is without dispute that on a global basis physicalsecurity has not been adequate to prevent the theft ofkilogram quantities of weapon-usable fissile materialfrom civil nuclear facilities. Over the past several years,at least seven serious cases of diversion of weapon-usablefissile material have occurred. Although North Koreasigned the NPT in 1985, it did not permit the IAEA toconduct inspections, as required by the Treaty, until May1992. In the interim, US intelligence believes NorthKorea has extracted 8-12 kg of plutonium at theYongbyon reprocessing plant (and possibly at one ormore hot cells) using irradiated fuel rods from its 5 MWereactor. Iraq initiated a crash programme in August 1990to build a nuclear weapon within eight months, byrecovering HEU from its inventory of French- andRussian-supplied research reactor fuel that was underIAEA safeguards. Iraq proceeded to divert the IAEAsafeguarded fuel and cut the top off one of the fuelassemblies before the programme was interrupted by theGulf War.

Three additional cases involved the theft of 1.5-3 kg

ofHEU, and two others involved over 100 grams ofHEUor plutonium. Most, if not all, of the five cases involvedmaterials stolen from Russian nuclear facilities, and intwo cases the materials were intercepted outside Russia.

Some may attempt to dismiss these cases and cite thehistorical record in 'good' countries with state-of-the-artcapabilities. But even here it is well established (fromexp<;nence at exi:;ting civil and military chemicalseparation (reprocessing) plants, naval fuel facilities,and mixed-oxide fuel facilities) that it is extremelydifficult (or even impossible) to provide in practice asufficient level of physical security and materialaccounting and control at bulk handling facilities thatprocess large amounts of nuclear weapons-usablematerial. The inventory differences at the THORP plantare kept secret, but on a plantwide basis are probably inthe range of 0.3-1 % of the throughput. On an annualbasis, this represents an uncertainty in the range of 20-70 kg of plutonium.

One of the difficulties in providing adequate physicalsecurity is that theft of materials can involve a collusionof individuals, including the head of the guard force, oreven the head of the company or agency. Despite havingguards at every bank, employees at the Bank of Creditand Commerce, Inc. (BCCI) were able to steal millionsof dollars from bank customers because the thieves wererunning the bank - the collusion was at the top. If thethreat includes the potential for collusion involving theguard force and facility directors, providing adequatephysical security in the West would require turning thefacility into a heavily armed site occupied by anindependent military force. In the former USSR, andnow Russia, the security of fissile materials has reliedheavily on guarding not only the facilities, but also thesecret towns and cities where the nuclear workforceresides. These large 'closed' areas are anathema to ademocratic society.

Of course, the principal role of physical security iscompletely reversed when the collusion involves ele-ments of the government itself. In this case the primarymission of the security apparatus is to hide theprogramme from outside scrutiny. It is now known thatat various times in the past, the governments of theUnited States, Japan (during World War II), formerSoviet Union, United Kingdom, France, China, Israel,India, South Africa, Sweden, Argentina, Brazil, Taiwan,Pakistan, North Korea, South Korea, and Iraq have hadsecret nuclear weapons development programmes. Inlight of this history, combatting the 'norm of secrecy'surrounding the operations of nuclear research anddevelopment complexes can be seen as an integral part ofany serious nuclear non-proliferation strategy. Over-coming the historic inability of the internationalcommunity to penetrate beyond a nation's declarednuclear facilities to inspect undeclared sites is nowunderstood by many countries to be a vital component ofany serious effort to detect and thereby deter clandestinenuclear weapon development programmes.

The international community's principal tool forpenetrating the secrecy of nuclear facilities is the powerof the IAEA to conduct inspections and requireadherence to strict MC&A procedures. The irony today,however, is that a 'peaceful-use' plutonium programmecan be abused to aid a proliferator's requirement forsecret fuel cycle facilities, which are becoming increas-ingly difficult to deploy in any case in the face ofcontinuing improvements in remote surveillance techni-ques, and increasing demands for more intrusive on-siteinspections. Under the prevailing interpretation of theNPT, a non-weapon state party is not barred frommaintaining an implicit nuclear weapons option, if this isdone by legally acquiring and operating sensitivefacilities under safeguards 'for peaceful purposes'. Inother words, the IAEA could well improve its capabilitiesfor uncovering, and thereby preventing, operation ofclandestine nuclear facilities, only to find that this non-proliferation strategy has been invalidated by a legalproliferation of declared fuel cycle facilities.

While there are numerous shortcomings in the designand implementation of IAEA safeguards, the focus herewill be the implications of three technical flaws.

(i) As noted previously, the IAEA's SQ values aretechnically incorrect: they are far too high.

(ii) Detection of the diversion of an SQ amount appliesto an individual material balance area, instead of theentire facility, or even country.

(iii) The IAEA's timely detection criterion cannot be met.

The IAEA permits facilities to reduce inventoryuncertainties by subdividing the facility into numerousmaterial balance areas. The facilities in fact should be sosubdivided; this provides added protection against asingle insider threat. But it must be recognized that thisdoes not afford adequate protection against a collusion ofindividuals, particularly in scenarios where elements ofthe state apparatus itself are engaged in the diversion.

Detection time (the maximum time that should elapsebetween diversion and detection of a significant quantity)should be in the same range as the conversion time,defined as the time required to convert different forms ofnuclear material into components of nuclear weapons.For metallic plutonium and HEU, the conversion time isseven to ten days; for other compounds of thesematerials, one to three weeks. These times are alreadymuch shorter than the period between inventories at anyfuel reprocessing plant operating today. Thus, there canbe no assurance that the primary objective of safe-guards - the timely detection of the loss or diversion ofsignificant quantities of plutonium - is now being, or canbe, met.

To meet the timely detection criteria, reprocessingplants would have to undergo clean-out inventories everyfew days, or weeks. But this would reduce their annualthroughput - and utility - practically to zero. It wouldalso drive up the cost of reprocessing. Plutonium recycle(the use ofMOX fuel in standard commercial light-water

218

reactors (LWRs) is already uneconomical due to the highcosts of reprocessing and fuel fabrication even whenconducted without a technically adequate level ofsafeguards. Similarly, the cost of the fast breeder fuelcycle is already vastly greater than that of the LWRoperating on the once-through cycle without plutoniumrecycle. Ensuring adequate safeguards on the breeder fuelcycle would only widen this cost disparity.

In Western Europe and Japan, consideration is beinggiven to near-real-time accountancy (NRTA) as a meansof improving the sensitivity and timeliness of detection.NRTA involves taking inventories at frequent intervals,typically once a week, without shutting down the facility.Effective implementation of NRTA and similar conceptsmay well be opposed by plant operators due to the addedcosts that would be imposed. In any case, the methodsand adequacy of practical NRTA system implementationare open questions. A case in point is Japan's Tokaiplutonium fuel production facility (PFPF) where MOXfuel has been fabricated for Japan's Joyo and Monju fastbreeder reactors since 1988.

The PFPF's production line consists of 17 intercon-nected glove boxes monitored by unattended, tamper-proof instruments, such as neutron coincidence counters.Following an April 1994 inspection conference with theIAEA, Japanese sources disclosed that approximately70 kg of plutonium was 'held up' in the remotelymonitored process line, and that the uncertainty in theNRTA system's measurement of this hold-up materialexceeded at least 8 kg, enough material for severalnuclear explosive devices. PNC agreed to design newglove boxes that reduce the amount of plutoniumdeposited in the process line, but astonishingly the IAEAdid not order the shutdown of plant and an immediateclean-out inventory.

Given that 2-3 kg is sufficient for a kiloton yieldweapon made from reactor-grade plutonium, the IAEA'sintervention was technically four years too late to providetimely warning ofa theft orriiversion,shollld an eventualphysical inventory demonstrate that kilogram quantitiesof plutonium remain unaccounted for. This initialapplication of NRTA, and the IAEA's sluggish responseto the difficulties encountered, hardly inspires confidencein the future successful implementation of NRTAtechniques in larger and more complex facilities withvastly greater flows of material.

In a recently published analysis of safeguards, the USCongressional Office of Technology Assessment ob-served:

'To date, the IAEA has not considered the possibilitythat it cannot safeguard large facilities such as theRokkasho reprocessing plant, but neither has itdemonstrated that it can. II

(f) Ensure efficient allocation of scarce capitalresources for energy development

In the United States in the I960s the prevailing view inthe commercial nuclear industry was that the cost of civil

Table 3. Fuel cycle economics - projections against reality1969 projections (in constant 1969 $)

1969 2020Uranium price ($/Ib U308) 8 50 (without breeders)Reprocessing ($/kgHM) 37 20

Reality (in constant 1995 $)1969

32150

Uranium Price ($/Ib U308)

Reprocessing ($/kgHM)

199510

900-2700& .

spent fuel reprocessing would be relatively low, and thatsubstantial cost savings could be realized recoveringplutonium and uranium and recycling these materials inlieu of mining and enriching additional uranium. Thisview was also shared by nuclear industry officials inother Western countries and the Soviet Union. In 1969,for example, the US Atomic Energy Commission(USAEC) prepared a cost-benefit analysis of the USbreeder reactor programme.12 In this analysis theUSAEC estimated that the cost of reprocessing civilLWR fuel would be $37.30 per kg of heavy metal(kgHM) initially. 13 Projecting that the reprocessingindustry would grow in size, the USAEC estimated thatreprocessing costs as a consequence of economies ofscale would drop to $19.70/kgHM by the year 2020.14

Due to inflation, these costs in today's (1995) US dollarsare four times higher, or about $150/kgHM initially and$80/kgHM in 2020.

Also, in 1969 the USAEC estimated that the electricalenergy demand and growth in nuclear power use wouldbe so great that without the introduction of breederreactors, low-cost uranium resources would be depletedand uranium prices would climb from $8/lb to $50/lbU308 ($17.6/kg to $11O/kg).15 In today's US dollarsthese prices would be $32/lb and S200/lb (S70/kg and440/kg), respectively.

It transpired, however, that the cost projections of theUSAEC were completely wrong. The cost of spent fuel

reprocessing went up instead of down, and the cost ofuranium after peaking at $44/lb U308 ($20/kg) in 1979,went down instead of up (Table 3). For example, today inthe West, estimates of the cost of spent fuel reprocessing(exclusive of charges for long-term high-level wastestorage, transportation, and burial) range fromS750/kgHM to $1800/kgHM.I7 Cogema and BNFLn:portedly charged their customers about $1400/kgHMto $1800/lcgHM to subsidize construction of theirrespective plants at La Hague and Sellafield.17 BNFL issaid to be charging about $900/kg for contracts thatwould cover the second ten-year operating period of itsTHORP plant at Sellafield.18 Spot prices of uranium arenow $7.25/lb to $10.50/lb U308 ($16/kg to $23/kg)(Fig. 2). Thus, in the West since 1969 the cost ofreprocessing in constant dollars has increased sixfold ormore, whereas the cost of uranium has gone down by afactor of 3. The economic benefits of reprocessing andplutonium recycle never materialized.

It is enlightening to compare the cost of usingplutonium as a MOX fuel in existing thermal reactorswith the cost of low enriched uranium (LEU) fuel for thecase where plutonium is treated as free goods. Thiswould be the case, for example, were the United States tooffer its excess plutonium from weapons to utilities freeof charge. Table 4 compares the cost of LWR fuel madefrom low enriched uranium fuel with the cost of MOXmade from free plutonium. Because of the high cost ofMOX fabrication, as seen from Table 4, it is unecono-mical to use MOX fuel in LWRs even if the plutonium isfree. The cost penalty is even higher if costs are incurredfor converting the plutonium from metal to oxide (Pu02),as would be the case with plutonium from weaponcomponents.

Table 5 compares the LEU and MOX fuel cycle costswhere the plutonium for the MOX fuel is recovered byreprocessing spent fuel from conventional power ('ther-mal') reactors. Table 5 represents the special case where

Table 4. Economic comparison of LWRjileis - assuming free plutonium (/995 USdollars per kilogram of heavy metal in fresh fuel) *

LEU fuel (4.4% U-235) MOX fuel (4.8% Pu)Uranium as UF6 330± 125tEnrichment services 650 ± 401Fuel fabrication 225 ± 30 Fuel fabrication 1500 ± 300Total 1200 ± 135 Total 1500 ± 300$1 US "'£0.65 "'0.8 Ecu*Sources: Holdren, J.P. et af. •Management and Disposition of Excess Weapons Plutonium -Reactor Related Options. National Academy of Sciences, Washington, D.C., 1995, 280-298;Chow B.G. and Solomon K.A. Limiting the Spread of Weapon-Usable Fissile Materials,RAND, Santa Monica, CA., 1993,32-37.tAssuming the enrichment plant operates at 0.2% tails assay and assuming \.5% losses inchemical conversion, in order to produce one kgHM of 4.4%-enriched fuel, 9.84 kg of U308

(= 8.344 kgU must be obtained), converted into uranium hexafloride (UF6), and then theuranium enriched from its natural level (0.711% U-235) t014.4% U-235. The calculationassumes a uranium yellowcake price of $(40± 15)/kgU, and conversion costs of$(9 ± I )/kgU.tAssuming the enrichment plant operates at 0.2% tails assay, in order to produce one kgHMof 4.4%-enriched fuel, 7.46 kg SWU is required. The calculation assumes the price ofenrichment services is $(87 ± 5)/kg SWU. Current SWU spot-market price is S82/kg SWUto $92/kg SWU (August 1995).

70

60~Q.i0 50&

40

30

20

10

01980

Year

_____ Contract price

---A- Restricted spot price

-+- Spot price

--v- Unrestricted spot price

all of the capital investment has been met by advancedpayments for separate reprocessing contracts, and there-fore the cost of reprocessing is limited to the operatingand maintenance cost. This case more closely representsthe second 10-year tranche of reprocessing contracts atTHORP in that two-thirds of the capital investment inTHORP reportedly has already been met. Table 5 alsotakes an optimistic approach to the reprocessors byincreasing the cost of natural uranium from $40/kgU(assumed in Table 4) to $60/kgU, and increasing the costof enrichment from $85/kg SWU to $IOOjkgSWU. Asindicated by Table 5, MaX fuel becomes even lesscompetitive if the costs of reprocessing have to be borne.Even if the reprocessing plant capital investment cost hasalready been met, the cost of a MaX fuel from plutoniumrecovered by reprocessing is about twice the cost of anopen cycle.

Table 5 shows the added cost necessary to recover thecapital investment of the reprocessing plant. The firstcase, based on the UK THORP reprocessing plant,assumes a $2.8· billion construction cost, 25-year plantlife, and 700 tons of annual throughput. The estimatedcost to construct the Rokkasho plant in Japan, which hasthe same capacity as THORP, has recently increased from$7.5 billion to $10-20 billion, some 3.6 to 7.1 timcs whatwe have assumed for THORP.

In sum, the closed fuel cycle cannot compete with theopen cycle - not now, nor in the foreseeable future.

Development efforts worldwide have demonstratedthat closing the nuclear fuel cycle - that is, reprocessingto recover plutonium and uranium from spent nuclearfuel for use on existing thermal reactors or fastbreeders - is uneconomical for the user. It is cheaper tooperate existing thermal reactors using low enricheduranium fuel, and fast reactors (breeders) will remainuneconomical for the foreseeable future. The putativebenefits of plutoniu:n recycle and the plutonium breeder.associated with their ability to utilize uranium resourcesmore efficiently, are not diminished if closure of the fuelcycle and commercial breeder development is postponedfor decades, and the spent fuel from existing conven-tional reactors is stored in the interim. Moreover, energysecurity in the nuclear sector over the next severaldecades can be achieved more cheaply, more quickly andmore reliably by stockpiling reserves of uranium.

Otto Frisch and Rudolph Peierls worked out theessential theory of the atomic bomb here in England in1940. As a consequence of their work the UnitedKingdom established the Maud Committee, the firstgovernmental body to study the feasibility of atomicweapons. Then the United Kingdom became a fullpartner with the United States in the development of thefirst atomic bombs. Once again we need the leadership of

Table 5. Economic comparison ofLWRfuels (1995 US dollars per kilogram of heavymetal in fresh fuel)*

LEU fuel (4.4% U-235)

Uranium as UF6 575±170t

Enrichment servicesFuel fabrication

746± 150:t225±30

Waste disposalTotal

750± ISO2300 ± 300

Reprocessing plant capital costrecoveryOperations & Maintenance II

Fuel fabricationPu incremental cost for storageand transportWaste disposalTotal

3400± 13501500±300

iOO±50

750± 1505750± 1400

Reprocessing plantCapital cost recovery:

THORP:Rokkasho:

2200±2oo12,OOO±5OO0

*See Table 4, Note *.tSee Table 4, Note t. The calculation assumes a uranium yellowcake price of $(60 ± 20)/kgU,and conversion costs of $(9 ± I)/kgU. The average EURATOM contract price for naturaluranium was $20.25/lb Ups ($52.64fkgU) in 1994.:tSee Table 4, Note :to The calculation assumes the price of enrichment services is$(100±20)/kg SWU. Current SWU spot-market price is $82/SWU to $92/SWU (August1995).In the United States the utilities must pay the Federal Government $0.001 per kilowatt-hour ofnuclear energy generated to cover the cost of the geological disposal of spent fuel. For a1000 MWe power plant operating at 70010 capacity, 32% thermal efficiency, and a fuel burnup of40 MWd/kgHM, this represents an annual payment of$6.132 million and an annual spent fueldischarge of 20 tHM/y, or $300/kgHM of spent fuel discharged exclusive of carrying charges,or about $20 billion available for the construction of a 70,000 tHM repository. Interim dry caskstorage is conservatively assumed to equal this amount, therefore $6oo/kgHM is taken as alower limit. It is argued that due to mismanagement of the high level radioactive wasterepository, the US Government's waste fund is too low. Therefore as an upper limit, the cost offinal storage is doubled.II A price of$900/kgHM has reportedly been offered for reprocessing at La Hague (France) andSellafield (UK) after the year 2000, down from the $140o-18oofkgHM for current contracts.The drop in price may well result from the calculation that most of the capital costs will havebeen recovered by then. A charge of $900/kgHM becomes a reasonable upper bound for futureO&M costs. The lower bound is derived by subtracting the reported capital cost component forTHORP (about $450/kgHM) from the post-2oo0 offered price, yielding $450/kgHM. Theaverage price is then converted to $/kgHM in spent fuel using the same method as for thecapital cost assuming that 4.6 to 5.3 kgHM of spent fuel must be processed to recover theplutonium needed to make one kgHM of fresh MOX (4.8% Pu).

the United Kingdom, this.time to preserve the option ofridding the world of nuclear weapons. As one of the fivedeclared nuclear-weapon states and a member of the UNSecurity Council, the United Kingdom could take thefirst bold step and give up its nuclear weapons. If thisstep proves too difficult politically, there are several lessbold initiatives that would further the disarmamentprocess. The United Kingdom, for example, could simplyremove its deployed nuclear warheads far from thedelivery systems and place them in secure storage.

While the United States is trying to return its militaryplutonium and that of Russia back into spent fuel, theUnited Kingdom is busily removing weapon-usableplutonium from spent fuel, a programme that onlyundermines efforts to dispose of the military stocks.

The road to the abolition of nuclear weapons willsurely be blocked if the United Kingdom, France, Russiaand Japan continue to insist on pursuing the widespreadcommercial use of weapon-usable fissile materials underan international safeguards regime that is incapable of

providing the timely detection of the diversion of thesematerials for military use.

At the dawn of the nuclear age, the authors of thefamous Acheson-Lilienthal plan for international controlof atomic energy clearly recognized the inherent militarypotential of fissionable materials used for avowedlypeaceful purposes. From the technical standpoint, a moreeffective approach to blocking further proliferation wouldbe a universal ban on the production, transfer, acquisi-tion, or isotopic enrichment of separated plutonium, andon the isotopic enrichment of uranium to greater than20% U-235. Alternatively, such activities could bebanned when conducted under national or most multi-national auspices, but permitted if conducted by a UNchartered international authority under the direct controlof the UN Security Council.

The United Kingdom and other nations having orplanning civil nuclear energy programmes with closedfuel cycles could make an important contribution to thenuclear disarmament process by voluntarily defening

221

further separation of plutonium until at least thefollowing three conditions are met: (a) the existingglobal inventories of separated plutonium, includingmilitary stocks, are radically reduced (b) effectiveinternational institutions and technical controls are inplace that will permit civil plutonium use without addingsignificantly to the risk of nuclear weapons proliferation(c) use of plutonium in the nuclear fuel cycle repr~sentsan economically rational investment of scarce public andprivate capital for energy development, in free and opencompetition with other energy resources.

Further enrichment of uranium above about 20% U-235 also should be curtailed, and existing stocks of HEUshould be blended promptly with natural or depleteduranium to obtain low enriched uranium for reactor fuel.

Acknowledgements

I wish to thank my colleague Christopher E. Paine for hisconsiderable contribution to this report and Robert S.Norris and Drew Caputo for their reviews and comments.

I. COCHRAN, T.B. us. Inventories of Nuclear Weapons andWeapon-Usable Fissile Material, NRDC Nuclear Weapon Data-book Series, Revised 26 September 1995.

2. DIAKOVA.S. Disposition of Separated Plutonium: an Overview ofRussian Program, paper presented at the Fifth International

Conference on Radioactive Management and EnvironmentalRemediation, Berlin, Germany. 3-8 September, 1995.

3. COCHRANT.B., NORRISR.S. and BUKHARINO.A. Making TheRussian Bomb: From Stalin to Yeltsin, Boulder, Westview Press,1995, Appendix C.

4. COCHRANT.B. et al. Making the Russian Bomb, p. 31.5. FETTER S., COCHRAN T.B., GRODZINSL., LYNCH H.L. and

ZUCKER M.S. Gamma Ray Measurements of A Soviet CruiseMi:si!e Warhead, Science, 18 May 1990, 828-834.

6. ALBRIGHTD., ARKIN W.M., BERKHOUTF., NORRIS R.S. andWALKER W. Inventories of Fissile Materials and NuclearWeapons, SIPRI Yearbook 1995: Armaments. Disarmament andInternational Security, Oxford University Press, Oxford, 317-336.

7. Ibid 323.8. HILLS C.R., PEASE R.E., PEIERLSR.E. and ROTBLATJ. Does

Britain need nuclear weapons. British Pugwash Group, 1995.9. COMMITTEEON INTERNATIONALSECURITYANDARMs CONTROL,

Management and Disposition of Excess Weapons Plutonium,National Academy of Sciences, National Academy Press,Washington, D.C., 1994, Prepublication Copy, 37.

10. GILINSKYV Plutonium. Proliferation and Policy, Commissioner,Nuclear Regulatory Commission, Massachusetts Institute ofTechnology, November I, 1976, Press Release No. S-I4-76.

II. Nuclear Safeguards and the International Atomic Energy Agency,OTA-ISS-615, Washington, D.C., June 1995,73.

12. US ATOMICENERGYCOMMISSION.Cost-Benefit Analysis of theUs. Breeder Reactor Program. WASH 1126, April 1969.

13. Ibid., 68.14. Ibid.15. Ibid., 70.16. CHOWB.G. and SOLOMONK.A. Limiting the Spread of Weapon-

Usable Fissile Materials, RAND, 1993,33-34.17. Ibid.18. Ibid.