- Text
Japan: Leaked radiation twice what was estimated
Smoke billows from the Unit 3 reactor at the Fukushima Dai-ichi nuclear power plant in Okuma, Japan. (AP Photo/Tokyo Electric Power Co.)
TOKYO - 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.
Special Section: Disaster in Japan
Above-limit radiation found on 2 Japan workers
UN: Japan nuke plants ill-prepared for tsunami
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."
The country acknowledged Tuesday in a report being submitted to the U.N. nuclear agency that it was unprepared for a severe nuclear accident.
The 750-page report, compiled by Japan's nuclear emergency taskforce, factors in a preliminary evaluation by a team from the International Atomic Energy Agency and was to be submitted to the IAEA as requested.
"In light of the lessons learned from the accident, Japan has recognized that a fundamental revision of its nuclear safety preparedness and response is inevitable," the report said. It also recommended a national debate on nuclear power.
The report said the flaws in basic reactor design included the venting system for the containment vessels and the location of spent fuel cooling pools high in the buildings, which resulted in leaks of radioactive water that hampered repair work.
The report said the vents lacked filtering capability, causing contamination of the air, and the vent line interferred with connecting pipes.
Desperate attempts by plant workers to vent pressure to prevent the containment vessels from bursting repeatedly failed. Experts have said the delay in venting was a primary cause of explosions that further damaged the reactors and spewed huge amounts of radiation into the air.
The melted cores and radiation leaks have irradiated workers, including two control room operators whose exposures have exceeded the government limit.
Lack of protection for plant workers early in the crisis and inadequate information about radiation leaks were also a problem, nuclear crisis taskforce director Goshi Hosono said.
The report acknowledged a lack of independence for Japan's nuclear regulator, the Nuclear and Industrial Safety Agency, and pledged to improve safety oversight, as recommended in the IAEA report last week.
Trade and Industry Minister Banri Kaieda promised to share all available data about the accident and cooperate with the IAEA.
"Our country bears a serious responsibility to provide data to the international community with maximum transparency and actively contribute to nuclear safety," he said.
After Chernobyl, Japan stepped up nuclear safety measures but that effort did not last long, Hosono acknowledged.
"We should never repeat the same mistake," he said.
- "Don't shoot": Qaddafi's last moments
- Libyan officials: Qaddafi killed in Sirte
- GRAPHIC VIDEO: Qaddafi's bloody body
- GRAPHIC VIDEO: Qaddafi wounded but alive
- GRAPHIC VIDEO: Chinese girl hit by truck, ignored by passers-by
- After toddler is left to die, China disquieted
- Clinton sees Qaddafi news on BlackBerry
- With warped vision, Qaddafi maddened Libya, West
- Rare Viking burial site found in Scotland
- Violence erupts amid massive Greece strike
- 23 women convicted of child pornography in Sweden
- Backpack drone a "magic bullet" for U.S. troops?
- Cockpit error sent 737 into Pacific nose dive
- Austrian women allege mass rapes at foster home
- Qaddafi hometown falls to Libya fighters
- Qaddafi reported dead
- Israelis 'shocked' at Egypt TV Schalit interview
- Poland still wants euro, central bank head says
- Poland still wants euro, central bank head says
- Japan Cabinet OKs $158 billion extra budget
- Fed threat gets results as Calif pot shops close
on Facebook
- The death of Muammar Qaddafi
- Preview: Steve Jobs
- Qaddafi dead after Sirte battle, PM confirms
- America's new favorite team: Wounded Warriors
- "Don't shoot": Qaddafi's last moments
on CBS News