“True nature of nuclear power plant accident remains sealed” : Our country does not allow either science or journalism to get to the bottom of a severe accident that deprived hundreds of thousands of people of their peaceful and stable daily life. Can we really call this a diplomatic country?

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“True nature of nuclear power plant accident remains sealed”

2013.4.12

Yoshio Shioya
Science journalist

More than one and a half years have passed since 3.11, but the question and doubt surrounding the true nature of the Fukushima nuclear accident have not been cleared up at all.

How were the equipment and systems in the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Plant was damaged when they were affected by the Great East Japan Earthquake and by tidal waves? And how did the damage and disorder caused by the earthquake and tidal waves lead to the “simultaneous multiple severe accidents” that were unprecedented in the world in which the adjacent four nuclear power facilities were gravely damaged one after another?

We still know nothing about the framework and scenario of the Fukushima nuclear accident.

In July of 2012, the reports from the government, the national diet and the independent accident investigation committees were put on the table. There are now four investigations reports that are open to the public including the report made by the TEPCO investigation committee, which is as strange as an incident investigation report made by a suspect. I read the four accident investigation reports over and over, but unfortunately, a dark and deep-seated question in my mind started to grow and multiply rather than dwindle or vanish.

Apart from TEPCO’s report, which does nothing but makes excuses to avoid responsibilities, all of the other three accident investigation reports sharply point out some fragments of the huge accident. However, they do not get to the main point, the bottom of the accident. I don’t believe that they can all possibly be viewed as the “conclusion” of an investigation, but rather they should be considered as a beginning or introduction of a full-scale accident investigation.

On the basis of the three accident investigation reports, the “second investigation committee” that has strong authority and enhanced investigative functions should be established as soon as possible. The truth about Chernobyl has been sealed up almost permanently in the sarcophagus consolidated by powerful politics and concrete, so the world has not properly shared the lesson and experience as of yet. If Japan repeats the same thing in the investigation of Fukushima, Japan will be viewed as a secret state worse than the former Soviet Union.

What is commonly missing in the four investigation reports is the basic understanding of the geographical, structural and social peculiarity of Japanese nuclear power plants.

In Japan, nuclear power plants are invariably built on a coastline of white sand and green pines in a relatively compact and concentrated manner. In the West; however, nuclear power plants are usually found scattered near a large river in an inland region and they have a huge cooing tower (equipment for releasing remaining heat from a power plant into the atmosphere by means of river water). In Japan, nuclear power plants dispose of waste heat that will not be used for power generation into the sea as warm waste water.

This small Japanese archipelago is hit by 40% of the earthquakes that measure at a magnitude 4 or more in the world. Japan is actually an incredible earthquake archipelago. So nuclear power plants in Japan cannot be compared with those in the West, which stand on a solid bedrock in a landlocked area near a large river boasting a stable amount of water flow, where there have been no earthquakes for more than one thousand years. Japanese plants are totally different from those in the West not only in terms of location, but also the risk of suffering damages due to earthquakes or tidal waves. These points need to be kept firmly in mind.

The most distinctive feature of Japanese nuclear power plants lies in the fact that a number of nuclear reactors stand very closely side by side in a little plot on a seaside plateau. The Kashiwazaki-Kariwa Nuclear Power Plant in Niigata Prefecture, which TEPCO is trying to restart, has as many as seven nuclear reactors and it is the world largest nuclear-power generating site in terms of generating power, when the outputs of the seven reactors are combined.

In July of 2007, the Niigataken Chuetsu-oki Earthquake struck Niigata Prefecture and the nuclear power plant was severely damaged. Soon after that, a research team dispatched by the International Atomic Energy Agency (IAEA) immediately arrived and entered the nuclear plant site from the seashore side. After the great severe accident at the Fukushima Daiichi power plant, Yukiya Amano, the Director General of the IAEA, immediately came back to Japan with a radiation measuring team in the midst of confusion right after the accident.

Japan, which provides nearly 30% of the operating fund of the IAEA, willingly accepted inspections by the IAEA for ensuring nuclear non-proliferation. The IAEA’s somewhat excessive response toward the nuclear accident in Japan which had been viewed as an honor student of the IAEA was undoubtedly due to the West’s strict evaluation of the seismic risk of Japanese nuclear plants that are standing side by side along a coastline of the earthquake archipelago.

Excessively building nuclear plants in a limited area has led to an abnormal accumulation of risk factors such as nuclear reactors and nuclear fuel, which has increased the risk of a severe accident, not by addition, but by multiplication. Unfortunately, this time what the West had been apprehensive of came to reality with the Fukushima Daiichi nuclear plant. It must be the origin and the starting point of an accident investigation to clearly establish the link between Japanese excessive building method and the severe accident in which Units 1-4 were consecutively damaged.

Most of the coastal areas are covered with a thick sand layer or sedimentary soil layer. You have to dig the ground very deep until you reach solid bedrock on which a nuclear reactor can be built. There have been many cases where the location of bedrock was so deep that the height of the installation position of a nuclear plant above the sea level was not enough, so a huge amount of concrete was poured onto bedrock before setting up a nuclear reactor. The Fukushima Daiichi nuclear plant was built in such a way.

Concrete poured onto a bedrock forms a mass of concrete called a “man-made rock.” The “man-made rock” at the Fukushima Daiichi nuclear plant has a thickness of 7 to 8 meters. Nuclear fuel in the reactor cores of Units 1-3 was thought to have melted down and eaten through the containment vessels, but there have not been any indications of the nuclear fuel melting out of the building sites, which might be due to the extremely thick man-made rocks there. It was indeed something good that came out of something bad.

The three nuclear power plants, the Onagawa Nuclear Power Plant of the Tohoku Electric Power, the Fukushima Daiichi and Daini nuclear plants of TEPCO, suffered from the same degree of quakes and tidal waves, among which, however, the altitude above sea level of the installation position of the plants in the Fukushima Daiichi nuclear plant is lower than those of the other two nuclear plants by two to four meters. Eight-meter-thick man-made rocks were put under the plant, but the installation position was probably not high enough to withstand gigantic tidal waves.

When comparing the three nuclear power plants, you can find another important fact that Units 1-4 in the Fukushima Daiichi nuclear plant, which underwent a severe accident, were of the old type and all of them were deteriorated nuclear facilities that had started to operate in the 1970’s. They were “hardened” nuclear power facilities whose time-related deterioration and structural defect of piping, reactor core structures, cooling system, etc. had been repeatedly pointed out.

Unit 1, which TEPCO directly imported from General Electric in the U.S., is said to have had no proper Japanese manual to deal with an acute emergency. The “Mark-1” type nuclear facility was designed on the assumption that it would be set up on stable ground in the inland area of a continent, whose basic design concept did not take earthquakes and tidal waves into consideration, so there had been increasing concern over the deterioration of the long piping network and the risk of its breakage by an earthquake.

TEPCO had repeatedly concealed inspection data and covered up troubles in nuclear plants including the Fukushima Daiichi nuclear plant, which was brought to light by an in-house whistle blower in 2002. It was conscientious past presidents and chairpersons, who placed importance on the social responsibility of a public utility, that resigned as a symbol of taking responsibility for that. After they were gone, what was left behind might have been the idea that “an electric company has a right to raise the electric rate.”

Considering the cooperate culture of TEPCO, the locational conditions, the structure and function of the reactors, it is possible to imagine that overall, the Fukushima Daiichi nuclear plant accident was a human-made accident that occurred because the hardened, high-risk and deteriorated nuclear generation facilities had not been well maintained and were not be able to withstand an expected earthquake disaster.

In the present electricity supply system, the longer deteriorated nuclear generation facilities are able to be operated, the more profitable the business will become. It costs a vast amount of money to decommission a reactor. Just procrastinating in the decommissioning of a reactor can produce profits in a relative sense. For electric power companies, operating decrepit electric generating facilities tastes like forbidden fruit that they cannot give up.

In the present electricity supply system, the longer deteriorated nuclear generation facilities are able to be operated, the more profitable the business will become. It costs a vast amount of money to decommission a reactor. Just procrastinating in the decommissioning of a reactor can produce profits in a relative sense. For electric power companies, operating decrepit electric generating facilities tastes like forbidden fruit that they cannot give up.

It was nothing but incomprehensible that the accident investigation committees did not intensively analyze this key point. They avoided handling the most important issues for making policy choices for the country, and so they did not live up to their names, the accident investigation committees.

After much ado, TEPCO released the video of teleconferences between the nuclear plant site and the headquarters office soon after the accident. Both the field site and the headquarters knew that there was nothing they could do to prevent a series of chain-reaction accidents, so they struggled to keep outsiders from knowing such potential risks, which could be seen via TV monitors.

The National Diet Accident Investigation Commission points to the groundless conclusion that TEPCO did not plan to withdraw its personnel; however, the contents of the video implies that the management personnel clearly intended to evacuate personnel to the Fukushima Daini power plant out of fear of the accident, inducing a chain of other accidents. TEPCO might insist that it was not a “complete” withdrawal because TEPCO was going to keep tens of security personnel out of 700, but such an excuse is not acceptable.

The question of whether the accident in Fukushima became so serious due to a chain-reaction or it was an independent event still remains unsolved, and we may have to wait until the second accident investigation committee analyzes the accident. However, it’s easy to assume that the risk of a series of accidents was something “top secret” that was not allowed to be widely known.

Our country does not allow either science or journalism to get to the bottom of a severe accident that deprived hundreds of thousands of people of their peaceful and stable daily life. Can we really call this a diplomatic country?

 

http://sciencelinks.jp/content/view/1306/33/

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