Stone Stymies Port Security?

NEW YORK – Any homeowner can tell the difference between a granite countertop and nuclear materials, but sophisticated equipment used for security screening at U.S. ports apparently couldn’t, according to a report by the New York Times.
An article by Eric Lipton earlier this summer documented a number of problems with freight inspection with screening devices with a collective $4.5 billion-plus price tag. Among the alleged flops in high-tech detection against terrorist threats are radiation monitors with a high sensitivity.
The Times article noted drive-through radiation monitors at New Jersey’s Port Newark Container Terminal. Sensors can detect radiation levels, but can’t determine the source. The search is for nuclear weapons, or material for use in crude radiation-poisoning devices called “dirty bombs” (as shown in the HBO/BBC movie Dirty War earlier this year).
According to the Times, granite is one of the materials emitting enough radiation to trip the devices. Among other materials that sound the alarm are cat litter, ceramic tile, porcelain toilets and the occasional bunch of bananas.
The Times noted that federal officials bought the best equipment they could get at the time, including the sensors that originally were designed for the scrap-metal industry. Research continues at a Nevada facility on better radiation monitors; as for the current devices, officials say, at least there’s a deterrent.