Lack of Data Heightens Japan’s Nuclear CrisisTOKYO — Nearly one month after Japan’s devastating nuclear accident, atomic energy experts, regulators and politicians around the world are still puzzling over a basic question: How much danger is still posed by the Fukushima Daiichi nuclear power plant? That depends to a considerable extent on how hot the uranium fuel rods at the power plant remain, and whether fuel has escaped its containment, or might still do so. Yet remarkably little is known for sure about what is really happening inside the reactors because some areas remain far too radioactive for workers to approach, and some instruments have malfunctioned.
The paucity of data and the conflicting estimates of what the available information really means have prompted a series of confusing analyses and a rift between officials in Japan and those overseas — and even between one member of Congress and the United States Nuclear Regulatory Commission.
The commission speculated this week that the nuclear fuel in the core of one of the stricken reactors had probably leaked from its thick steel pressure vessel, its most important protective barrier. If that proved to be accurate, it would raise the prospect of continuing fuel leaks and high levels of radioactive releases that would vastly complicate containment and the cleanup.
But 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.
From the start there have been differences, with the American authorities expressing a more pessimistic view than the Japanese.The rift also highlights the difficulty of a debate in which both sides are forced to extrapolate possible situations with little access to crucial readings from inside the reactors.
Much of the automated measurement equipment in the reactors has been damaged, either by explosions in the early days of the crisis or by intense radiation since then. Damage to the reactors, as well as high radiation, has prevented technicians from making detailed assessments.
Even so, it is not easy to explain why such different theories are being offered on fundamental questions like whether radioactive fuel from the steel reactor pressure vessel at Unit No. 2 is leaking into the bottom of the containment structure.
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.
In addition, there is evidence that an explosion may have breached the primary containment structure, which may have allowed highly radioactive water into other parts of the plant and into the ocean. This week, Representative Edward J. Markey, Democrat of Massachusetts, an outspoken critic, engaged in a running debate with members of the commission’s staff over the conditions at Reactor No. 2 in Japan. Mr. Markey said the regulators had told his staff that fuel was leaking from the reactor, but then the commission issued a more ambiguous public statement.
“I find it rather curious that some within the Nuclear Regulatory Commission are attempting to deny the findings their own technical staff conveyed to my office as soon as it became clear that this information showed a meltdown that is more severe than some people apparently wish to acknowledge,” Mr. Markey said in a statement.
On the Japanese side, officials have an obvious desire to avoid causing panic in public statements.
The Japanese also seem to prefer presenting raw data without explaining what they think it means, said Takashi Inoue, a professor of public relations at Waseda University. Every day, Tokyo Electric, the nuclear agency, the chief cabinet secretary and others hold news conferences at which they present a blizzard of facts and numbers but rarely make broader declarations about the conditions at Fukushima Daiichi.
Masashi Goto, a former Toshiba nuclear power plant designer, said that Japanese officials appeared to have decided that they gained nothing but panic from predicting outcomes. “They will never speak about the worst-case scenario,” he said. “They will never predict.”
Link -
http://www.nytimes.com/2011/04/09/world/asia/09nuclear.html?pagewanted=2&_r=1=================================
That's a reasonably fair way to put it!
A Paucity of information.
Paucity, meaning -
the presence of something only in small or insufficient quantities or amounts; scarcity
scantiness: a country with a paucity of resources
This is another situation where real facts are as scarce as hens teeth!
