Nuclear sniffer

US nuclear power company Westinghouse Electric, which was recently acquired by Toshiba of Japan, has been developing a clever new way to spot nuclear contraband.Many US ports already Xx-ray ship containers to see if they contain hidden nuclear material. But Xx-ray machines may fail to spot hidden uranium or plutonium if it is hidden behind lead shielding.So Westinghouse Electric proposes using generating a powerful controlled beam of neutrons by propelling deuterons into tritium. These will then cut through lead shielding and excite any fissile material, creating an "echo" of neutrons caused by a "fast fission" effect.The echoes only last a microsecond or so and are quickly damped out, so there is no risk of a triggering a chain reaction. But they can be detected by a silicon carbide semiconductor sensor, which is switched on and off in between the trigger pulses. The sensor then gives instant and unambiguous warning of hidden nuclear cargo.