IN VIENNA, Austria, scientists are listening for clandestine nuclear tests. In Norway, other researchers are trying out a device that reveals the contents of a nuclear missile without betraying its deepest secrets. And 1000 kilometres east of Moscow in Votkinsk, 30 Americans who watch Russians make missiles to aim at other Americans may not be coming home at Christmas after all.
The world is in the midst of an unprecedented wave of negotiations aimed at saving global agreements to keep nuclear weapons in check. Few realise that this involves at least as much science as it does diplomacy. The weapons treaties involved are totally dependent on verification science: inspections, remote monitoring and other methods of ensuring that people do not build or conceal banned weapons.
The diplomats can only rescue the treaties if they convince sceptics that verification works, so scientists are launching a renewed research effort to enable verifiers to keep pace with the bomb makers. Keeping the world from blowing itself up now depends on which scientists win: the bombers or the verifiers.
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“Keeping the world from blowing itself up depends on which scientists win: the bombers or the verifiers”
The focus of attention is the 1968 Nuclear Non-Proliferation Treaty, due to be reviewed by its member states in New York in May 2010. The NPT was a three-part deal. The five existing nuclear powers vowed to “pursue negotiations in good faith” to reduce and abandon nuclear weapons. The non-nuclear countries promised not to acquire them. And everyone got the right to peaceful nuclear power so long as no material was diverted to bomb-making, as verified by the International Atomic Energy Agency (IAEA).
“It is a miracle the NPT was ever adopted,” as it decrees a world of nuclear haves and have-nots, says , the physicist and government minister who guided Brazil’s retreat from nuclear weapons. The inequality of the deal kept some nations from ever signing. Israel’s nuclear bomb is an open secret; India and Pakistan tested theirs in 1998 (see map).
Now countries in the NPT are defying and even leaving it. North Korea left and tested a bomb in 2006, and again last month; while Iran is also suspected of a clandestine programme. IAEA chief Mohamed ElBaradei fears that up to 20 more countries could remain non-nuclear within the NPT but covertly acquire the technology and materials to assemble a bomb at short notice – especially as many are planning their first nuclear power plants. North Korea is suspected of helping Syria do just that: this month, IAEA verification experts reported particles of uranium in Syria that were too enriched to be natural.
The problem, says Goldemberg, is that the NPT requires countries to forgo nuclear weapons in return for the nuclear powers making genuine efforts to disarm completely, not just reduce their nuclear arsenals. There has been little sign of this happening. That is why US president Barack Obama and Russian president Dmitry Medvedev declared in April that their ultimate goal is indeed the complete abolition of nuclear weapons.
To keep the deal alive, Obama spelled out what needs to be done in a speech he gave in April in Prague. First, the Comprehensive Test Ban Treaty (CTBT) must enter into force, or at least get closer to it. Second, the US and Russia must extend their 1991 Strategic Arms Reduction Treaty (START) to cut nuclear missiles before it expires in December this year – and with it the only ongoing verification in existence of the two countries’ nuclear arsenals. And third, the world must negotiate a new treaty limiting the production of the fissile material used in bombs. Each of these depends critically on making governments believe the treaties can be verified.
The CTBT would be a serious step towards disarmament: no tests effectively means no new weapons. But it still requires ratification by all 44 countries that had nuclear plants when it was signed in 1996, and nine have not done this. The US Senate refused to ratify it in 1999: opponents feared that the treaty’s verification network – hundreds of seismographs, radionuclide sniffers, infrasound and hydroacoustic monitors – would not catch small nuclear tests.
Last month, that network proved itself by spotting a test in North Korea. Partly as a result, “I think the US will ratify within a year,” says Hans Kristensen of the Federation of American Scientists. That could break the logjam of remaining hold-outs, starting with China, says CTBT spokeswoman Annika Thunborg.
Meanwhile, the wide-ranging but cumbersome verification methods developed for START need refinement. In December, the US and Russia are expected to agree to cuts in each side’s estimated 2000 to 3000 deployed long-range weapons to 1500 apiece, and to maintain current verification. This is based largely on inspections, remote sensing and detailed nuclear accounting. It includes the Americans in Votkinsk, and their Russian counterparts in Utah, ensuring each sticks to agreed limits on missile production.
For deeper cuts, the two powers need better verification. One problem is missiles with multiple warheads. Inspectors must verify how many warheads are inside sealed tubes, says Andreas Persbo of , a pro-verification organisation in London, but they cannot just look inside – the missiles hold secrets their owners are obliged to keep.
Last week, VERTIC and British and Norwegian scientists ran the first field trials of a device that could solve the problem: a gamma ray detector linked to a hand-held “information barrier”. The detector picks up the full spectrum of gamma radiation emanating from a missile, “but looking at that would reveal more than we need”, says Persbo, such as what metals were alloyed with plutonium to make the “pit” of the device, or how and when the fissile material was made. “If two radiation energies common to all plutonium are there, the information barrier will just say ‘yes’ or ‘no’,” says Persbo. The first trial run of the system in Norway last week successfully verified a test object containing cobalt-60.
Verifying the US-Russia arms agreements will be such a big job, says Joan Rohlfing of the arms control group Nuclear Threat Initiative, that “it creates a new research agenda”.
It will require even more to verify a new treaty on the production of fissile material. In 1995, the United Nations voted to negotiate a treaty to ban the making of fissile material that can be used in bombs, but negotiations have been deadlocked since then, partly because the US refused to accept the inspections required.
That changed in April when Obama called for a “verifiable” : negotiations started this month. Such a treaty should extend verification measures to the military enrichment and reprocessing plants that are not now covered by international monitoring, and prohibit unmonitored production. Many of the accounting methods now used to check what flows through civilian nuclear fuel plants will be applicable. Efforts to put fuel enrichment and reprocessing into international hands would also help, although IAEA member states were unenthusiastic at meetings this month.
To detect covert enrichment, says Kristensen, “what we learned from weapons inspections in Iraq will be very powerful”, especially the wide-area environmental monitoring that the IAEA used in Syria. This means sampling air and water for particles containing enriched uranium, plutonium or other telltale isotopes. Yet this technology will have to improve: that for a network of detectors to be reliable, for instance in a country like Iran, its samplers must be no more than 10 kilometres apart. Putting such a grid everywhere is not feasible.
“Lessons from weapons inspections in Iraq will be very powerful, especially in environmental monitoring”
Not all, and possibly not any of these treaties, and their accompanying verification, will be complete by the NPT meeting in May next year. At best, they will show the nuclear powers are serious about their promises on disarmament. The world will have to wait to see if that convinces the nuclear have-nots.
