From earlier today:
"but not an explosion" Famous last words...Japanese officials and experts have been at pains to say that while there would be radiation leaks, they would be very small and have dismissed suggestions of a repeat of a Chernobyl-type disaster.
"No Chernobyl is possible at a light water reactor. Loss of coolant means a temperature rise, but it also will stop the reaction," said Naoto Sekimura, a professor at the University of Tokyo.
"Even in the worst-case scenario, that would mean some radioactive leakage and equipment damage, but not an explosion. If venting is done carefully, there will be little leakage. Certainly not beyond the 3-km (1.8-mile) radius."