Prospects for the Fissile Material Cutoff Treaty

You can’t build a nuclear bomb without fissile material. Before global disarmament is possible, that stuff must all be located and secured.

By Michael Wallace

President Barack Obama’s speech on nuclear disarmament in Prague was a breakthrough for US policy For one thing, he expressed commitment to creating a Fissile Material Cut-off Treaty (FMCT). This had long been a goal of disarmament activists, who initially had expected it to be negotiated in Geneva at the UN Committee on Disarmament (CD). India’s and Pakistan’s nuclear tests in 1998 showed that the CD could not produce such a treaty, but there was hope that the 2010 Nuclear Non-Proliferation Review Conference might develop a program for such work.

And indeed, the US delegation (supported by a large majority of the national delegations) tried to ensure that the 2010 Review Conference outcome would advance beyond the 2000 Review Conference and—especially— beyond the fiasco of the 2005 conference. The final document welcomed the newly-inked START treaty between the US and Russia and strongly affirmed past commitments and efforts to ratify the long-delayed Comprehensive Test Ban Treaty (CTBT).

Unfortunately the final FMCT language was relatively feeble, showing little new progress. A number of states (led by China) blocked a strong statement calling for a moratorium on the production of highly enriched uranium (HEU) or plutonium for the purposes of making weapons. Given this weak statement in the 2010 final document, combined with the CD’s failure to agree on a program of work toward limiting the production of fissile materials, must we conclude that a FMCT is at present dead in the water?

The outcome of the 2010 NPT final document, while disappointing, does not mean that the FMCT has stalled completely. It was expected that states with relatively small stocks of fissile material would be leery of giving up the right to augment them. But there are two other, larger groups of states who are anxious to reduce or dispense with fissile materials:

It might seem impossible to strike an enforceable deal to satisfy both states that produce or wish to produce fissile materials, and those that wish all such production stopped, for whatever reason. The problems multiply when we try to define precisely what a “Cut-Off” Treaty would mean.

What is “fissile material”?

There are two basic types of fissile material. First is Uranium isotope 235, which can be extracted from the mixture of isotopes found in nature by using high-speed centrifuges to increase the proportion of U-235, i.e. “eneriching” it. At about 90+% it emits enough high-speed neutrons to start a chain reaction. The second type of fissile material is plutonium, made in a reactor by irradiating uranium. Isotope 239 is referred to as “bomb-grade,” because it emits a relatively large number of highi-speed neutrons to start a chain reaction, but relatively few low-energy (thermal) neutrons that might start the reaction prematurely and get a “fizzle” instead of a “bang”—which would be the most likely result with isotopes 240 and 241. They are called “reactor-grade.” At first, reactor-grade material could not be used in bombs.

However, some countries have discovered ways of using isotopes 240 and 241 for bombs, albeit with a lower, less reliable yield. This is important because several nations (including Japan and India) hold a considerable portion of their plutonium stocks as reactor-grade material. An effective treaty would have to include reactor-grade plutonium.

Which fissile materials are “cut off”?

Drafting a FMCT requires us to define what we mean by “cut-off.” Will all existing fissile materials be covered by the treaty? For some nations “cut-off” simply means: Stop production of fissile material immediately! Others want existing stocks included as well, which means an undertaking to render some or all of existing fissile stocks unusable.

Using the narrower definition of “cut-off,” all signatories are prohibited from any further production. You do not use your centrifuges to enrich uranium and you do not use your reprocessing units to separate plutonium from spent fuel rods. Whatever you have already enriched or separated is part of existing stocks and you may use it as you will, including by fabricating additional nuclear weapons. Countries such as Japan, which has excess stocks of plutonium, would not be prohibited from fabricating nuclear weapons from them by such a FMCT. (However, their status as non-nuclear weapons states under the NPT would constitute such a prohibition).

Seeking a broader definition of “cutting off”

Many states were hoping the NPT final document would propose to restrict or reduce existing stocks in some way. The quantities of fissile material held by some Nuclear Weapons States are far in excess of any security requirement. The US and Russia have tacitly acknowledged this by unilaterally “blending down” a large portion of their stocks of HEU to LEU (low enriched uranium), and have helped other states to blend down unwanted stocks of HEU left over from the Cold War.

Critics argue this does not go nearly far enough. Even if the “superpowers” agreed to cut their stocks drastically, there must be some formula for further reductions. Otherwise, Pakistan, for example, (which does not have large stocks of fissile material) would feel disadvantaged by a cut-off vis--vis India, **India vis--vis China, and China vis--vis Russia and the US. This issue led China to insist on weakening the language for a proposed FMCT at the 2010 NPT review conference in May. Unless a serious attempt is made to break this impasse, a FMCT will remain stalled.

This impasse has led a large number of non-nuclear states to the view that a FMCT should not only cut off further production, but ensure that a proportion of existing stocks be rendered unusable as explosive fissile material. Put bluntly, they want a FMCT to be in part a disarmament treaty as well.

Though many NWS are reluctant to address the issue of surplus fissile material, the quantities alone constitute an overpowering reason for doing so. Here I’ll summarize the current volumes of fissile materials in the world:

These quantities are staggering; the surplus HEU stocks could be fabricated into 25,000 Hiroshima-yield weapons, the plutonium into 30,000-60,000 Nagasaki-sized weapons (assuming a crude “minimal design” requiring 25kg for an HEU weapon and 4-8 kg for a plutonium weapon). It is highly unlikely that this surplus material would be converted into weapons, but any notion of “cut-off” must guarantee that it will not.


As we can see from the numbers above, any FMCT without provisions for verification would be toothless.

The simplest way to establish a verification regime would be under the IAEA. However, as the brouhaha involving Iran and its commitments to the IAEA amply demonstrates, simply turning verification over to the IAEA will not in itself bring into being an enforceable verification regime.

On the other hand:

The Future

Despite the lack of FMCT progress in the 2010 NPT final document, there is still cause for optimism. Not only did it represent a vast improvement over the diplomatic failure of 2005, but the signing and (one hopes) ratification of START, built on experience harking back to the 1987 INF Treaty, gives us hope that progress toward global disarmament may begin anew.

Michael Wallace is an emeritus professor of political science, University of British Columbia.

Peace Magazine Oct-Dec 2010

Peace Magazine Oct-Dec 2010, page 14. Some rights reserved.

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