GAO report queries new radiation detectors

Washington Post : Federal investigators at the GAO say the next generation radiation detectors—that are scheduled to be bought by the Department of Homeland Security—are only marginally better at detecting hidden nuclear material in cargo containers than monitors already at US ports, but would cost more than twice as much.The monitors now in use can detect the presence of radiation, but they cannot distinguish between threatening and nonthreatening material. Radioactive material can be found naturally in ceramics and kitty litter, but would be of no use in making a bomb, for instance.The DHS has said the new machines it is developing can distinguish between kitty litter and dangerous radioactive material and produce fewer false alarms than the current ones.The new one are also better at detecting lightly shielded material. But the machines perform at about the same level when detecting radiological and nuclear materials hidden in a lead box or casing, the most likely way a terrorist would try to sneak the materials into this country.