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information about Fukushima published in English in Japanese media info publiée en anglais dans la presse japonaise

US worried about Fukushima... a year ago

February 22, 2012

U.S. worried about Fukushima meltdown early on: commission transcript



WASHINGTON (Kyodo) -- The U.S. Nuclear Regulatory Commission released Tuesday some 3,000 pages of transcripts from the days following Japan's tsunami and nuclear disaster last March, showing that U.S. officials were concerned at an early stage about possible meltdowns at the Fukushima Daiichi nuclear plant and their debate over the scope of the evacuation zone.

The documents showed that as early as March 16, five days after the accident, NRC Chairman Gregory Jaczko projected "a worst scenario" that all three operating reactors at the crippled plant might be experiencing meltdowns.

"The reactors would likely eventually...breach primary containment and have some type of (radioactive) release," he said during a conference call, while adding that "it's difficult to predict the magnitude of that released."

The prediction turned out to be accurate and showed that NRC officials viewed the situation gravely, a stark contrast to the lack of crisis management in the Japanese government which took months before finally acknowledging that there was a meltdown.

On the evacuation zone for U.S. citizens in Japan, NRC officials were discussing as early as March 12 whether a 50-mile evacuation zone for U.S. citizens would be appropriate.

On March 16, when asked about the impact on Tokyo if the wind kept blowing in its direction, Jaczko said, "At this point, I think I would still go with the 50 miles right now is what we see as the actual direct evacuation. But it is uncertain and it would possibly have to get beyond 50 miles. I don't know that we've run a model out yet to Tokyo."

Similarly, Bill Borchardt, NRC's executive director for operations, also said, "If this happened in the U.S., we would go out to 50 miles. That would be our evacuation recommendation."

The 50-mile evacuation radius for U.S. citizens was about four times farther than what the Japanese government urged at the time and some had criticized it for fueling fear and tension in Japan.

The transcripts also showed that Jaczko mentioned "potentially up to six spent-fuel pools in a degraded condition, possibly with spent fuel pool fires."

The NRC officials also believed that the spent fuel pool in the No. 4 reactor had been substantially damaged to the point that it could no longer retain water, which is needed to prevent the rods from releasing radiation into the atmosphere.

The documents, released in response to Freedom of Information Act requests, consist of phone conversations at the commission's operations center during the first 10 days after a magnitude-9.0 earthquake and massive tsunami on March 11 triggered the worst nuclear accident in Japan's history.



US nuke regulator releases March 11 transcripts



Newly released transcripts of the US nuclear regulator show it contemplated an evacuation advisory for US citizens near the Fukushima Daiichi nuclear plant soon after the March 11th earthquake and tsunami.

The regulator's thinking was based on a worst-case scenario of meltdowns at all 3 operating reactors after they sustained heavy damage in the disaster.

On Tuesday, the Nuclear Regulatory Commission released more than 3,000 pages of transcripts, covering in-house conferences over 10 days from March 11th last year, when the massive quake hit northeastern Japan.

The documents show a senior member calling for evacuating people within a radius of 50 miles, or about 80 kilometers, from the plant about 2 days after the disaster on March 12th US eastern time.

Cesium had been detected within the plant compound, apparently leading the official to believe the cores of the reactors could be partially damaged.

On March 16th US eastern time, Chairman Gregory Jaczko pointed out the Number 1, 2 and 3 reactors may all melt down in the worst case.

Executive director for operations Bill Borchardt said the United States would issue an evacuation advisory for people within a radius of 50 miles if a similar case occurred in the country.

The US ultimately issued an evacuation advisory for its citizens on March 16th.
The Japanese government issued an evacuation notice for those within a radius of 20 kilometers and also urged those in areas between 20 to 30 kilometers to stay indoors.



US was worried about cooling of spent fuel pools




Newly released minutes from a US nuclear commission show a US regulator had concerns about the cooling of spent fuel pools at the Fukushima Daiichi nuclear plant one day after the accident took place on March 11th.

Documents from the US Nuclear Regulatory Commission show the agency chairman received a report from a senior official one day after the accident on the condition of the building that houses the No. 1 reactor. The report said that the reinforced frames of the building that holds a spent fuel pool were exposed after a hydrogen explosion damaged the building.

Agency officials expressed concern that Japanese authorities had provided little information about whether the cooling of the pool was being carried out properly.

At that time, the Japanese government and the Tokyo Electric Power Company were busy looking into the hydrogen explosion and taking safety measures for other reactors.

Four days after the accident, the Japanese authorities finally noticed the cooling of spent fuel pools at the No. 3 and 4 reactors were not being carried out properly. A cloud of steam from the No. 3 reactor building was one of the factors that alerted the authorities to the problem.

Six days after the accident, helicopters from Japan's Self-Defense Forces sprayed water to cool the pools.

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