Verification Holds Key to Nuclear Arms Reduction Treaty

THE advent of the H-bomb, the intercontinental missile, and other new weapons systems has helped power the arms race. Will the arrival of the gamma ray detector, tamper-proof tags, and new verification technologies help halt superpower nuclear competition? Last week a team of United States scientists clambered aboard a Soviet cruiser in the Black Sea and used radiation detectors to monitor a nuclear antiship missile. The point was to demonstrate how limits on sea-launched cruise missiles might be verified. But the experiment was highly controlled, and many experts say high-tech gadgets alone will not solve verification problems.

Enforcing a new strategic-weapons agreement, or limits on conventional arms in Europe, or a chemical arms ban will necessarily involve human monitoring of production sites, spot-checks of suspect facilities, and other intrusive measures far beyond even those already agreed to for the intermediate-range nuclear forces (INF) pact. ``There is no simple and easy technical fix,'' says Michael Krepon, a verification expert at the Carnegie Institute.

The Black Sea experiment was unprecedented in one sense. Rarely, if ever, have US scientists, albeit nongovernmental ones, been allowed within touching distance of an actual Soviet nuclear warhead.

By placing various radiation sensors on the launch tube of the SS-N-12 missile for about 10 minutes, the US delegation gained valuable data that amount to an identification card for the weapon, Steve Fetter, a University of Maryland scientist, claimed afterwards. Such information could be used to help count the numbers of nuclear-tipped sea-launched cruise missiles (SLCMs).

The Soviets are eager for a new strategic arms treaty (START) to include limits on SLCMs, and they claim such a limit could be adequately verified. But the Bush administration says these small, now-ubiquitous weapons cannot be adequately tracked, and so should not be included in any START pact.

Pentagon officials were so vocal in their criticism of the Black Sea experiment that they convinced at least one private analyst to drop out of the trip. US government officials say that at different times the Soviets themselves have claimed different capabilities for the demonstrated radiation sensors.

``Sometimes they say you'll be able to tell the number and type of nuclear weapons on board,'' says one US official. ``Then they say this technology must operate in a context of `other cooperative means.'''

The Pentagon says the radiation sensors can be easily spoofed by such actions as lining missile launchers with metal shielding.

Thus they would be useful only in conjunction with intrusive on-site ship visits - something the US Navy strongly rejects.

Still, the US government is itself hard at work developing new verification technology. The Department of Energy, the agency that designs and produces nuclear warheads, also has a new Office of Arms Control, which is charged with developing systems to help verify both current arms agreements and treaties that might be signed in the future.

This year the DOE will spend about $150 million on verification technology research and production.

``Instrumentation is being developed to operate in seismic bore holes and on geostationary satellites, to cover signals with frequencies from fractions of a hertz to those of gamma rays, to measure masses as small as one-millionth of a millionth of a thousandth of a gram and energies equivalent to that released by ... a thousand-million pounds of TNT,'' Victor Alessi, director of the Office of Arms Control, told Congress earlier this year.

New verification technology already developed includes special scales, cameras, and X-ray equipment intended for use by US crews watching a Soviet missile factory, in conjunction with the INF Treaty.

``Tagging'' nuclear missiles with special paint, bar codes such as those on supermarket products, or fiber-optic seals is one monitoring technique that might surface in any START treaty.

To monitor conventional weapons reductions in Europe, some analysts have suggested use of unattended acoustic or infrared sensors scattered around garrisons or borders.