Robert (Food, Inc.) Kenner’s investigative doc arrives a little late — it chronicles the 1980 accident that caused a Titan II missile to blow up in its Arkansas silo because of human error. But the point is well taken, that the handling and deployment of nuclear weapons is a risky business, maybe too risky for this country to be involved in. Kenner’s supremely suspenseful film, which he directed, co-wrote, and co-produced, is adapted from a book by Eric Schlosser, also of Food, Inc. fame, and relies on talking heads testimony by almost everyone involved, including the airman who dropped the socket that ruptured the fuel tank that caused the missile to explode (without, thankfully, detonating the nine-megaton warhead). Worth a look for worried pacifists and anyone else (92 min.). By Kelly Vance