Japan doubles estimate of nuclear radiation leak

By the Associated Press | June 7, 2011 | 6:59 AM EDT

In this June 1, 2011 photo released Saturday, June 4, 2011 by Tokyo Electric Power Co. (TEPCO), workers inspect equipments inside the cesium absorption tower, part of the radioactive water processing facilities at Fukushima Dai-ichi nuclear power plant in Okuma, Fukushima prefecture, northeastern Japan. The Japanese utility battling to bring its radiation-spewing nuclear reactor under control said Sunday, July 5, 2011 that 1,500 more tons of radioactive water are being moved into temporary storage in the processing facilities, the latest attempt to prevent a massive spill of contaminated water into the environment. (AP Photo/Tokyo Electric Power Co.) EDITORIAL USE ONLY

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."