TOKYO (AP) -- Japan's government has doubled the estimate of how much radiation leaked from a tsunami-hit nuclear plant and says the damage to the reactors was greater than previously thought.
The Nuclear and Industrial Safety Agency says in a report that nuclear fuel inside three reactors at the Fukushima Dai-ichi plant probably melted through not only the reactor cores but also through the inner containment vessels.
The report Monday said twice as much radiation may have been released into the air as earlier thought. That would be one-fifth of the amount released at Chernobyl instead of the earlier estimate of one-tenth.
NISA said its analysis used a different method than had been employed by the plant's operator last month and is believed to "better reflect reality."