LONDON (AP) — Nuclear submarines from Britain and France collided deep in the Atlantic Ocean this month, authorities said Monday in the first acknowledgment of a highly unusual accident that one expert called the gravest in nearly a decade. Officials said the low-speed crash did not damage the vessels’ nuclear reactors or missiles or cause radiation to leak. But anti-nuclear groups said it was still a frightening reminder of the risks posed by submarines prowling the oceans powered by radioactive material and bristling with nuclear weapons.——Contact the Daily Reveille’s news staff at [email protected]