Report: Puts Fukushima's Radiation Release at 1/6th of Chernobyl's

JUDY WOODRUFF: A just-released report is shedding new light on the severity of the nuclear crisis in Japan.

It's been three months since the massive earthquake and tsunami ravaged the Fukushima Daiichi nuclear plant in Japan. And now an official report says the amount of radiation released was more than double the earlier estimates. That means it was one-sixth the amount dispersed at Chernobyl in 1986, the world's worst nuclear disaster.

Initially, the Fukushima radiation was rated one-tenth the total at Chernobyl. The report comes from Japan's Nuclear and Industrial Safety Agency. It acknowledges that three reactors at Fukushima suffered core meltdowns and likely breached their containment units.

GOSHI HOSONO, special adviser to Japanese prime minister (through translator): At present, there is damage to the bottom of the reactor container. We call this core melting in English. Part of the fuel fell into the dry earth floor, and it is possible that it is still lodged there.

JUDY WOODRUFF: Massive explosions from built-up gases rocked the plant in the days after the tsunami. The report blames faulty venting technology in the 40-year-old reactor. It also says the government was unprepared for a severe nuclear event and that regulators lacked independence from the private nuclear utility companies they were directed to oversee.

In the days just after the March 11 catastrophe, there were confused and contradictory, but usually upbeat assessments. They came from Tokyo Electric Power Company, which owns Fukushima, and from Japanese government officials.

YUKIO EDANO, Japanese chief cabinet secretary (through translator): There is no need for unreasonable worry. And I think people should respond calmly.

JUDY WOODRUFF: For thousands of people, a 12-mile no-go zone around the nuclear plant remains in place. Voluntary evacuations are in effect for the area 12 to 19 miles out, with selective mandatory displacements enforced.

Even those outside the nuclear zone and well away from the devastated coast still feel the effects. The fear of power blackouts has led to a wide-ranging conservation drive.

RYU MATSUMOTO, Japanese minister of the environment (through translator): We have an electrical power shortage this year, and the government is calling for 15 percent cuts in usage.

JUDY WOODRUFF: Part of the campaign, loosening the famous formality of Japan's business world, trading high collars for casual wear, and setting summer office thermostats to a tropical 82 degrees.