Nuclear mattersTrust but verify, II

Any credible arms-control and nuclear weapons nonproliferation regime must be based on effective and reliable verification systems. Last week, the Verification Research, Training and Information Center (VERTIC) and British and Norwegian scientists ran the first field trials of a device that could solve the problem of reliable verification: a gamma ray detector linked to a hand-held “information barrier.” Debora MacKenzie writes that 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 U.S.-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 UN 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” Fissile Material Cut-off Treaty, and negotiations started this month. MacKenzie writes that 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. This technology, though, will have to improve: modelers have calculated that for a network of detectors to be reliable, for instance in a country like Iran, its samplers must be no more than ten kilometers 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,” writes MacKenzie. “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.”