JAPAN | Nuclear accident disclosure

Posted on July 8, 2011


JAPAN | JAPAN TIMES | 8 July 2011

The Atomic Energy Society of Japan, an academic society made up of experts on nuclear power engineering, nuclear reactor physics and radiology, on Monday issued a statement criticizing the government, Tokyo Electric Power Co. and other related institutions for delays and insufficiency in their disclosure of information concerning the accidents at Tepco’s Fukushima No. 1 nuclear power plant, which began March 11.

People will give an approving nod to each of the points raised by the society because these points accurately show what they have been feeling about the behavior of the government and Tepco in connection with the Fukushima nuclear crisis.

The society says that the delay in the data disclosure is extremely regrettable and that the information has been insufficient.

Since the Atomic Energy Society of Japan is regarded as close to Japan’s nuclear power establishment, the criticism bears importance all the more.

The government, Tepco and other related institutions should closely examine their past behavior as to information disclosure and quickly change their attitude.

The society says that people’s worries about the nuclear accidents and the spread of radioactive substances have increased because the process of information disclosure is cloudy and the information that has been provided is conflicting.

The following point is especially important. The society notes that there is the possibility that the damage to people’s health from radiation exposure has increased because the government, Tepco and other related institutions did not properly disclose information on the status of the nuclear accidents and the environmental contamination by radioactive substances.

It says that although they had information that must be disclosed, they have not done so.

An example that surfaced recently is the education and science ministry’s failure to immediately disclose the name of a radiation hot spot in Namie, Fukushima Prefecture.

Tokyo Shimbun’s Wednesday report says that although the ministry started monitoring the radiation level in the Akougi mountainous area in Namie on March 17 on the basis of a prediction by SPEEDI (System for Prediction of Environmental Emergency Dose Information) and detected a high radiation level of 150 microsieverts per hour or more at an early date, its website did not disclose the area’s name until April 11. It only mentioned “(32) about 30 km northwest.”

The radiation data were not used to evacuate local residents until the government decided on evacuation on April 22.

The society also takes the parties concerned to task over cases in which announcements have been made in Japan only after the data had been disclosed in reports intended for consumption abroad, and cases in which no announcements have been made in Japan although the information is provided abroad.

One example mentioned by the society concerns the reports on the meltdowns in the Nos. 1, 2 and 3 reactors at Fukushima No. 1. On June 6, the Nuclear and Industrial Safety Agency announced that a simulation pointed to the possibility that meltdowns had occurred in each of the three reactors and that molten nuclear fuel had pooled at the bottom of the pressure vessel of each reactor. The next day, the government admitted that a more serious situation may have developed in the three reactors.

In its report for a conference of the International Atomic Energy Agency, the government pointed to the possibility that molten nuclear fuel had drained out of the pressure vessels and dropped to the bottom of the containment vessels.

Understandably the society strongly criticizes the government for disclosing this serious development as late as almost three months after the crisis started and for disclosing the information only through a report intended for an international meeting.

The society also cited the handling of information on the arrangement of spent nuclear fuel rods in a cooling pool for the No. 4 reactor at Fukushima No. 1. It says that the U.S. Energy Department disclosed on May 26 a detailed diagram showing the arrangement of the spent nuclear rods as well as the results of its analysis on the situation.

The society points out that the data on the arrangement of the spent nuclear rods came from Tepco and that the information has not yet been disclosed in Japan even though it would be useful in determining the cause of the destruction of the reactor’s outer building.

The cases clearly show that the information disclosure process is flawed. (The society also gave other examples.) The society notes that such vital information as the temperature of the lower section of the pressure vessels, the volume and temperature of the coolant water in the lower part of the pressure vessels, and the temperature of the molten nuclear fuel have yet to be released.

The government, Tepco and other related institutions should take a serious view of society’s criticism that the problems in information disclosure have hampered experts’ efforts to analyze the Fukushima nuclear accidents and offer advice on how to regain control of the situation.

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