United States Government May Revise Its Fukushima Evacuation Advice

On March 16th, the United States government issued a warning about the Fukushima Daiichi nuclear accident, calling for an evacuation of all American citizens within a 80-kilometer (50-mile) radius of the power plant. Following the United States’ example, several other foreign countries also announced 80-km evacuation zones. The Japanese government, however, maintained that its 30-km safety zone around Fukushima Daiichi was adequate. The gap between the U.S. and Japanese advice caused a great deal of international suspicion about the trustworthiness of the Japanese government.

However, it now seems that the United States is reconsidering its evacuation advice:

The U.S. Nuclear Regulatory Commission issued an evacuation advisory for Americans living within an 80-km radius of the troubled plant on March 16. The decision was based on the assumption that fuel at the No. 2 reactor at the plant was completely damaged, not on observational data.

Based on the limited data it had at the time, the NRC may have overestimated the levels of radioactive substances that would leak from the nuclear plant.

NRC officials also attributed the review of the evacuation advisory to improvements in the situation surrounding the crippled nuclear plant.

The Asahi Shimbun has printed an English language article about American nuclear engineers questioning the government’s decision:

“This was a very, very important decision. I would have expected there would have been high-level conversations between our regulatory bodies and our government (with their Japanese counterparts)”, said Sam Armijo, former head of GE’s nuclear fuel business, who invented the fuel cladding used on boiling water reactors.

“I want to make sure we get the analysis and the numbers that were actually used,” Armijo said.

[...]

The recommendation was not based on actual data from the site, which was unavailable, Sullivan said.

“Maybe the Japanese had some of that, but we didn’t, alright?” he told the committee during a heated, lengthy question period.

Some of the NRC’s assumptions were based on press reports, said William Ruland, the NRC’s acting deputy director of engineering and corporate support.

“In an emergency event, you go with the best available information you have at the time,” Ruland said, noting Japanese counterparts were focused on containing the situation rather than providing U.S. officials with information.

Michael Corradini, head of the nuclear engineering department at the University of Wisconsin, said the NRC’s evacuation recommendation left him “confused.”

He questioned why the NRC did not correlate its modeling with data from radiation monitors in the country before publicizing its recommendation.

“Thirty-two years ago, if Japan would have done a what-if calculation on Three Mile Island and said all the Japanese within 50 miles of Harrisburg should get out, what would be our response, from a policy standpoint?”

The New York Times appears to have spun the story of the NRC engineers’ criticism to fit its familiar narrative of suspicion towards the Japanese government, running it with the headline “Lack of Data Heightens Japan’s Nuclear Crisis.” Nevertheless, the article does include some interesting quotes from Japanese officials, many of whom are wondering what data the foreign media has been using to make

Japanese officials said there was no evidence of a compromised pressure vessel, and they wondered why they were reading about it in the newspapers.

“If they have a concern, they should inform us,” said Kentaro Morita of Japan’s nuclear regulatory body, the Nuclear and Industrial Safety Agency, after its American counterpart sounded the alarm over a possible nuclear fuel leak at the plant’s Reactor No. 2, clearly contradicting Japanese accounts. “They didn’t say such concerns to us directly,” Mr. Morita said.

A senior Foreign Ministry official, meanwhile, accused the foreign media of exaggerating the threat posed by the power plant and the radiation spreading from it. Radiation fears are hurting sales of Japanese products abroad.

[...]

The Nuclear Regulatory Commission cited high levels of radiation at one spot inside the containment structure at Reactor No. 2 as evidence for its analysis. In addition, extremely high levels of radiation were detected in the water from a recently stanched leak that ran from the reactor building into a drainage ditch and into the ocean.

The Japanese flatly deny that possibility. “At this moment we do not have any data that shows there has been leakage to the containment vessels,” said Hidehiko Nishiyama, deputy director general at the Japanese regulatory agency. He also said that the Japanese and American regulators, who talk every day, were no longer so far apart on this question.

The American media and American government have little to lose when they speculate about a nuclear accident occurring on the other side the world. Aside from nuclear scientists, there are few Americans who would probably be angry about the fact that their government was wildly speculating when it advised a 50-mile evacuation area for Fukushima.

The Japanese government, on the other hand, has a much riskier situation on its hands. If it follows the American government’s example and doesn’t base its decisions on actual data, it would lead to unnecessary mass panic. If the Japanese government underestimates the threat and gives inadequate evacuation orders or inadequate food safety regulations to citizens, it would also face major problems. Likewise, if it is ever revealed that the government knowingly concealed vital information from the public, it would be political and career suicide for those responsible.

Related Link: A few days ago, Obama administration sources told the LA Times that they believe the crisis at Fukushima is “ebbing”:

….there is no evidence that overheating during the last month has resulted in any melting of the reactor vessels or their containment structures, Obama administration officials said Thursday.

If that assessment is correct, then significant additional releases of radioactivity into the environment will be limited, and emergency crews should have a far better chance of preventing further damage to the plant’s reactors.

• Akihabara News – Gadgetry from Japan (Subscribe)
• Dannychoo.com – Your portal to Japan (Subscribe)