Fukushima investigation

The Kan Cabinet on May 24 established a third-party panel to investigate the accidents at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power plant. The move was extremely tardy, coming 2? months after the start of the nuclear crisis and nearly one month after Prime Minister Naoto Kan’s announcement of his intention to create an investigation body. The panel met for the first time on Tuesday.

It is strongly hoped that panel head Mr. Yotaro Hatamura — a professor emeritus at the University of Tokyo and an authority on study of errors and dangers — and the rest of the panel members will thoroughly investigate all important points related to the nuclear crisis because it is a matter of great concern not only for Japan but also for other countries.

There are more than 430 nuclear reactors in 30 countries. Naturally their operators and the governments concerned are carefully watching the events unfolding at Fukushima No. 1. Some governments are worried about the spread of radioactive substances from the plant. The accidents that have occurred at Fukushima No. 1 are extremely grave and must not be forgotten. A large tsunami knocked out all power sources for the reactors — an event unprecedented in the history of nuclear power generation — thus rendering the reactors’ emergency core cooling system inoperative.

A Tepco simulation shows that large-scale meltdowns occurred in the Nos. 1, 2 and 3 reactors. The simulation shows that all or most of the fuel became molten and collected at the bottom of the reactors. It is also feared that the pressure vessels of these reactors have sustained holes. It is also feared that the suppression chamber of the No. 2 reactor has been damaged. Hydrogen explosions occurred in the Nos. 1 and 3 reactors, and separate explosions occurred in the Nos. 2 and 4 reactors. The resulting radiation leaks have forced the evacuation of some 100,000 Fukushima residents.

The panel’s main task should be to draw a detailed, full picture of the accidents by finding out how and why Tepco and the government failed to contain the situation, thus allowing it to develop into a major disaster. The panel should also study the degree of radioactive contamination and its possible effects on human health.

Some people may want to see criminal punishment meted out to people in management positions who failed to bring the accidents under control. The ultimate purpose of the panel’s investigation, however, should be to gather and disseminate lessons from the accidents to help prevent future nuclear power-related accidents not only in Japan but also abroad. The panel should make it clear that it will not leak or submit to courts any testimony, information and material that it collects in the course of its investigation. This will encourage people involved to speak openly and honestly to panel members.

The government should immediately order relevant personnel and organizations to keep all information and documents related to the accidents safe. The strong possibility also exists that the government itself does not have a written record of important decisions that it made. If this is the case, it could hamper the panel’s investigation.

The panel does not include anyone who has ties with the nuclear power establishment to ensure the neutrality of its investigation. But it should consider getting help from nuclear safety and regulation experts from abroad. This would help increase the objectivity of the panel’s investigation and make the results more acceptable to governments and nuclear power plant operators and regulators abroad.

The panel should investigate all the relevant organizations involved including the Kan Cabinet, Tepco, the Nuclear and Industrial Safety Agency (NISA), the Atomic Energy Commission and the Nuclear Safety Commission.

The government says that the panel will be able to question anybody it views as indispensable to the investigation, including Mr. Kan, his aides and trade and industry minister Mr. Banri Kaieda. But the panel has no legal power, and some people may balk at cooperating with it. The government should immediately enact a relevant law to give the panel teeth.

People have many questions about the nuclear accidents at the Fukushima No. 1 plant. The panel should strive to resolve questions such as:

? To what extent did the tremors from the March 11 earthquake damaged important reactor pipes?

? Was the timing of the steam venting and sea water injection into the reactors correct? Could an earlier venting and injection of sea water have prevented the accidents from becoming more serious?

? Why did Tepco and the government accept foreign help to contain the accidents in a slow, piecemeal manner?

The panel plans to issue an interim report by the end of 2011 and a final report by the summer of 2012. The panel should not unnecessarily delay its investigation, and each time it has discovered important data or reached an important conclusion it should promptly disclose the information.

On May 25, a group of experts from the International Atomic Energy Agency started their own investigation into the nuclear accidents and, on June 1, submitted a summary report to the Japanese government. This indicates the international community’s strong interest and concern about the nuclear crisis. The Japanese side, especially Tepco and NISA, should fully heed the team’s recommendations.