President Obama's nuclear summit in Washington has brought together leaders of 47 nations in pursuit of an elusive goal: to lock down unsecured nuclear material within the next four years and prevent it from getting into the hands of terrorists. That agenda would be difficult enough if nuclear material weren't already circulating on the black market, but it is.
WNYC's Bob Hennelly has been looking into what happens if a "dirty-bomb" is detonated. A conventional weapon wrapped around radioactive material, a dirty bomb is easier to make and obtain than a nuclear bomb, as it requires far less nuclear material than a fission bomb. Bob tells us about the tension between what officials should tell us about the threat of a dirty bomb and what they can tell us.