Eliminating Nuclear Threats

A Practical Agenda for Global Policymakers



GARETH EVANS and YORIKO KAWAGUCHI CO-CHAIRS                    Commission Members

12. Limiting the Availability of Fissile Material

The Proposed Fissile Material Cut-Off Treaty

12.1     Role and importance of the treaty. The proposed treaty to verifiably ban the production of further quantities of fissile material for use in nuclear weapons is as important a building block for both non-proliferation and disarmament as the CTBT. But, given current differences of perceived national interest between those nuclear-armed states which have a sufficiency or surfeit of fissile material (the U.S., Russia, France and UK) and those who seem to wish to preserve the freedom, at least for some time, to add to their stocks (India and Pakistan, and possibly China), and taking into account North Korea’s current intransigent position, it is likely to prove no less difficult than the test ban treaty to quickly negotiate and bring into force.

12.2     The fissile materials in question are basically high enriched uranium (HEU) and separated plutonium. For present purposes HEU is usually defined as uranium enriched to 20 per cent or more in the isotope uranium-235, from which a nuclear explosive device could theoretically be made, but in practice this is likely to require enrichment to 70 per cent or more U-235, and weapons grade HEU is usually defined as 90 per cent or more. For safeguards and general non-proliferation purposes a conservative approach is taken, erring on the side of caution on the basis that HEU at the lower end of the range has potential as a feedstock for higher enrichment.

12.3     The plutonium of interest in the present context is “separated” plutonium, because this essentially man-made element, produced by irradiating uranium fuel in reactors, is not available for use in nuclear weapons until separated from spent fuel by reprocessing. Weapons grade plutonium is usually defined as containing a low proportion of the isotope Pu-240 as compared with the isotope Pu-239 (no more than 7 per cent of the former, and a correspondingly high percentage of the latter) which requires reactors to be designed and operated in a particular way which is inefficient for power production. Spent fuel from the normal operation of power reactors contains only “reactor grade” plutonium, which typically contains 25 per cent or more Pu-240, and a correspondingly lower proportion – 60-70 per cent – of Pu-239. Again, however, for policy purposes a conservative definitional approach is taken, given at least the theoretical possibility of producing a nuclear explosive device from reactor grade plutonium.

12.4     Non-nuclear-weapon states party to the NPT have already given a commitment, verified by IAEA comprehensive safeguards, not to produce fissile material for nuclear weapons. The essential purpose of the proposed Fissile Material Cut-off Treaty (FMCT) is to apply a similar commitment – including appropriate verification – to the nuclear-weapon states and the non-NPT parties, in a new non-discriminatory treaty of universal application. A moratorium on the production of the relevant material is being observed by four of the five NPT nuclear-weapon states, but possibly not by China, apparently not by India and Pakistan outside the NPT (Israel’s position is unclear), and certainly not by North Korea. Making the moratorium a legal obligation of general application through an FMCT would help to stabilize the general security environment, reducing the prospects of future arms races and contributing to the irreversibility of nuclear disarmament measures. An FMCT, with verification provisions emphasizing state accounting for and control of fissile materials, should also contribute positively to the strengthening nuclear security, reducing the possibility of dangerous material falling into the hands of non-state actors.

12.5     Efforts to get negotiation started on an FMCT began in 1995, when it was hoped that the Conference on Disarmament (CD) would move on to this immediately after it concluded its work on the CTBT. The “Shannon Mandate” of that year, named for the then Canadian CD ambassador, appeared to signal agreement on negotiation of a treaty that would be non-discriminatory, fully multilateral, and internationally and effectively verifiable, but that turned out to be a mirage. The CD wasted fourteen years struggling to agree on a negotiating mandate, until – with the U.S. reversing opposition to verifiability which it had maintained during the previous administration – something of that kind was finally adopted in June 2009. But endless further possibilities remain for disagreement on matters of agenda, specific work program, meeting schedules and the like, not to mention the very substantive issue of existing stocks, discussed separately below.

12.6     The principal issue that needs to be settled in the negotiations is the proposed treaty’s scope – the materials and facilities that will be covered. At a minimum it should apply to new production (i.e. post the treaty’s entry into force) of fissile material, with verification arrangements applied to newly produced fissile material to ensure it is not used for nuclear explosives, and enrichment and reprocessing facilities to ensure that all new production is declared.

12.7     Verification. A crucial issue will be how verification is implemented. In this regard, there is already a well-established system directly relevant to FMCT objectives, i.e. IAEA safeguards. Every state relevant to FMCT already has a safeguards agreement with the IAEA, albeit of more limited scope in the nuclear-weapon states and the non-NPT states. Building on the existing IAEA safeguards system, supplementing existing safeguards agreements as necessary, makes sense in technical (existing expertise), economic (rational use of scarce human resources) and political acceptability terms. Difficult as they will be, the verification issues are not in themselves insuperable, since the inspections would not require access to nuclear warheads and their associated facilities.

12.8     FMCT safeguards should be non-discriminatory, in contrast to the NPT regime. HEU enrichment and processing facilities, reprocessing and plutonium-separation facilities should come under a regime which treats nuclear-armed and non-nuclear states in the same way. But, as with the NPT, issues of enforcement would need to be referred to the UN Security Council.

12.9     As part of implementing verification in a cost-effective manner, a state-level approach could be developed, building on experience being gained with the state-level approach in IAEA safeguards. With a state-level approach, the technical verification objectives and parameters will be the same for all states, but decisions on verification intensity could take account of state-specific factors.

12.10     A major challenge will be implementing verification approaches in old facilities not designed with verification convenience in mind, i.e. enrichment and reprocessing plants in the nuclear-weapon states. These are likely to require intensive verification effort, and the more of these facilities that can be shut down and decommissioned, the more manageable the verification task will be. A further particular challenge will be establishing appropriate verification arrangements against diversion of fissile material used for non-prescribed non-peaceful purposes – i.e. naval reactor programs.

12.11     The greatest verification challenge will be addressing the possibility of undeclared fissile material, i.e. nuclear material and activities that are required to be declared under the FMCT. This would be a substantial departure from the current situation, where the nuclear-weapon states and non-NPT parties have nuclear material and facilities outside any safeguards coverage. Under the FMCT, these states will continue to have some unsafeguarded material (in particular, in the form of nuclear weapons) and locations where this material is stored and processed (e.g. processing for stockpile stewardship). However, it will be essential to provide for verification activities to counter, and to investigate, possible undeclared production of fissile material, which clearly would be a violation of the FMCT.

12.12     Irreversibility. The key provisions of the FMCT should be irreversible, meaning for a start that if a state were to withdraw from the FMCT, safeguards agreements would not automatically lapse as a consequence. The FMCT should also contain provisions for the dismantling of existing fissile-material production facilities, somewhat along the lines of the Chemical Weapons Convention. It is one thing to stop the production of HEU and weapons-grade plutonium by mothballing corresponding facilities which can rapidly resume their activity; it is quite another to destroy the ability to durably prevent uranium enrichment and plutonium extraction.

12.13     It has to be acknowledged that dismantling fissile material production facilities is a lengthy and costly process, although somewhat quicker and cheaper in the case of HEU enrichment facilities, than for reprocessing plants. In the French experience, the dismantling of the military enrichment capability in Pierrelatte has been achieved in around a decade at a cost of under 1 billion euro; the comprehensive build-down of the military reprocessing facility in Marcoule is a multi-decade enterprise (with long cooling-off periods) at an estimated cost of some 5 billion euro. These costs would have to be multiplied to eliminate the much larger similar facilities in the U.S. and Russia.

12.14     Other Issues. The entry-into-force section of the treaty will also pose issues for negotiators. In order to reach agreement, there may be a temptation to make entry into force conditional on ratification by specified states, as is the case with the CTBT. The nuclear-weapon states, for example, even though most if not all of them clearly have all the fissile material they could possibly need, may not be willing to enter a formal commitment unless the non-NPT states do likewise. But there will be, equally, a reluctance to make commencement of the treaty hostage to one or two hold-outs.

12.15     Given the suspicion that tends to accompany treaty negotiations of this kind, that one’s rivals will drag out the negotiations to preserve maximum freedom of action for themselves for as long as possible, it would be desirable to make a general voluntary moratorium on fissile material production a first priority, extending the present commitment of the present four states to all the others, and it would be helpful if other key states in the international community could encourage that course. But it has to be acknowledged that this issue is bound to be caught up with larger ones about regional and global strategic tensions and balances, and may not be any easier to reach agreement on than the text of the FMCT itself.

Pre-Existing Stocks

12.16     While it is important that the FMCT negotiations focus on putting in place as soon as possible a regime cutting off future production of fissile material for use in nuclear weapons, some consideration of the issue of what to do about pre-existing stocks – i.e. holdings of fissile material pre-dating the FMCT’s entry-into-force – cannot be avoided.

12.17     The difficulty of making the treatment of stocks a formal part of the treaty negotiations now starting – such that the objective would, in effect, be an “FMT” (Fissile Material Treaty) rather than an FMCT – is that this would be a far more complicated exercise, needing altogether more intrusive and sensitive verification arrangements, involving close scrutiny of military facilities. The stocks issue will certainly have to be addressed as disarmament proceeds: if significant fissile stocks remain free of any constraints, they could be drawn on to produce additional nuclear weapons, and there would be concerns about the durability of quantitative warhead limits agreed in disarmament negotiations. Certainly it is inconceivable that any final move to zero would be possible without this issue resolved.

12.18     While the FMCT’s governance, compliance and safeguards system can and should be crafted in a manner which subsequently may facilitate the negotiation of a FMT, and it should be understood from the outset that a cut-off treaty cannot be the end of the exercise, the appropriate approach to adopt is a phased one, making the first priority setting a cap on production, and only then proceeding to stock reduction, with the objective being to ensure that all fissile material other than in weapons would become subject to irreversible, verified non-explosive use commitments, and that as weapon reductions and dismantlement are agreed, fissile material released through dismantlement is also brought under these commitments.

12.19     The Commission supports, as an interim step, the idea proposed by Robert Einhorn for a “Fissile Material Control Initiative” (FMCI), under which nuclear-armed states would voluntarily make regular declarations of their fissile material stocks; apply the highest standards of physical protection and accountancy to those stocks; regularly declare amounts of fissile material they regard as excess to their weapons needs; place such excess material under IAEA safeguards as soon as practicable; and convert excess material as soon as possible to forms that cannot be used for nuclear weapons.

Fissile Material in Civil Programs

12.20     The FMCT as presently conceived will not prohibit outright the production of all fissile material, provided this is under verification. But since fissile materials generally are of proliferation and terrorism concern, it is highly desirable for their availability to be limited, and their use should be phased out as viable alternatives are established.

12.21     Nuclear materials at or near weapons grade are unusual in civil programs. High enriched uranium is not used in power reactors, but it does remain in widespread use in research reactors. Since 1978 there has been an international program – Reduced Enrichment for Research and Test Reactors (RERTR) – to convert HEU-fuelled reactors to low enriched uranium fuel, or to shut them down, and to return HEU fuel to the U.S. or Russia who have supplied most of the research reactors involved. World-wide, to date 62 research reactors have been dealt with in this way, but some 130 research reactors or critical assemblies in over 40 countries are still operating on HEU fuel – totalling some 20 tonnes of HEU. Clearly the completion of this program and the withdrawal of HEU from civil programs remain high priorities.

12.22     Weapons grade plutonium is not normally produced and used in civil programs, except in the case of fast breeder reactors, which are very limited in number. If alternative fast neutron reactor designs prove viable, the production of weapons grade plutonium can and should be avoided (as addressed in Section 14, in the discussion of proliferation-resistant technology).

12.23     The most important need, in the case of plutonium, given that it can only become available in any form for nuclear weapons by separation from spent fuel through reprocessing, is to move away from any technology which can separate pure plutonium: as also discussed in Section 14, the optimal solution is to use it for reactor fuel, but without entirely separating it at any stage from highly radioactive materials.

12.24     For the present, however, developments are moving the other way. “Closed” recycling of plutonium for further use as reactor fuel in fast neutron reactors is attracting increasing interest on efficiency grounds, because this dramatically reduces the quantities of uranium consumed and radioactive waste produced. But the present technology still involves separation of pure plutonium from other materials along the way, and if the proliferation and terrorism risks are to be minimized this will have to change. This is the objective of Generation IV research discussed in Section 14.

12.25     Currently a number of countries – principally the UK and France, and also Russia, Japan and India – reprocess power reactor fuel to recycle recovered plutonium as MOX (mixed oxide) fuel in thermal reactors, mostly light water reactors. MOX fuel has been in regular use for over twenty years, and currently is used in some 30 reactors in Europe, with a total of around 40 reactors licensed. Japan proposes to license sixteen reactors to use MOX fuel. World-wide, it now provides around 2 per cent of annual nuclear fuel requirements.

12.26     Strict security standards are specified for the processing, transport and handling of MOX fuel. To date these have proven effective, and there have been no significant incidents of loss or theft of MOX. However, the larger the number of countries and facilities involved, the greater the risk of incident. If new technologies for spent fuel treatment are established, avoiding current forms of reprocessing altogether, use of conventional (“aqueous”) reprocessing plants and use of MOX fuel can be phased out. Meanwhile, it is essential to ensure that use of MOX fuel continues to be tightly regulated and covered by rigorous security measures.

12.27     A related issue concerns disposition of plutonium recovered from nuclear weapon dismantlement. Such plutonium must be held under strict conditions of security and verification, and rendered unsuitable for nuclear weapons as quickly as possible. One way of doing this is to use the plutonium as reactor fuel. However, since by definition plutonium from warheads is weapons grade, it is absolutely essential to ensure its protection against theft by terrorists or proliferant states. MOX fuel made with weapons grade plutonium should not be considered equivalent to normal MOX – weapons grade plutonium should be protected at a similar standard as nuclear weapons, so the use of such plutonium in reactors must remain under close government control.


Recommendations on Limiting the Availability of Fissile Material

22. All states should negotiate to an early conclusion in the Conference on Disarmament a non-discriminatory, multilateral, internationally and effectively verifiable and irreversible Fissile Material Cut-off Treaty (FMCT), banning the production of fissile material for nuclear weapons or other nuclear explosive devices. [12.1–14]

23. All nuclear-armed states should declare or maintain a moratorium on the production of fissile material for weapon purposes pending the entry into force of such a treaty. [12.15]

24. On the question of pre-existing stocks, a phased approach should be adopted, with the first priority a cap on production; then an effort to ensure that all fissile material other than in weapons becomes subject to irreversible, verified non-explosive use commitments; and with fissile material released through dismantlement being brought under these commitments as weapon reductions are agreed. [12.18]

25. As an interim step, all nuclear-armed states should voluntarily declare their fissile material stocks and the amount they regard as excess to their weapons needs, place such excess material under IAEA safeguards as soon as practicable, and convert it as soon as possible to forms that cannot be used for nuclear weapons. [12.19]

26. The use of HEU in civil research programs should be ended as soon as possible, and the availability and use of separated plutonium in energy programs phased out as viable alternatives are established.[12.20–27]


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