Energy

Fukushima Disaster

What was the key factor which brought about the Nuclear Power Plant Disaster?

01/12/2011
Interviewed by Akiko Hayashi, Translated by Ichiro Fukuchi, Edited by Matt Murphy [FUKUSHIMA PROJECT]

“The disaster which occurred at the TEPCO (Tokyo Electronic Power, Co.) Fukushima No.1 Nuclear Power Plant, was simply brought about by human errors on the side of the technology management, and not by disaster or coincidence. This accident was 100% predictable.” ---noted Professor Eiichi Yamaguchi, Doshisha University, Deputy Director of Institute for Technology Enterprise and Competitiveness (ITEC).
Professor Yamaguchi has been in the process of researching the root of the disaster by taking a closer look at the technology management as the chairman of the “Fukushima Project”. The purpose of this project is to analyze the disaster from a 3rd party stance in order to avoid problems of conflict due to financial or other interests which could potentially arise. After doing so a kind of recommendation plan for the future will be provided.

Q. As a technology management and theoretical physics professor, what is your personal view on this recent disaster?

Prof. Yamaguchi : As I am an individual with no anti-nuclear or pro-nuclear views, who simply looks at this problem from a clearly objective point of view, I was quite surprised when the news reported that the tsunami had been the primary factor for the power loss and complete loss of control on site. Japanese engineers tend to work on the basis of social justice and ethics, rather than the order of an organization of which they happen to belong to. This means that Engineers generally plan out counter-measures in such a way to ensure that there is a fail-safe for any kind of situation, in this case it was their "last fortification" to protect against the unknown. With this in mind, it is hard to imagine that they would design the power plant without some kind of back up emergency power support plan to protect against power loss or malfunction. Having followed my hunch to begin researching this further, just as I had expected, I was able to find what they had designed as their “last fortification”.

Q. What was it?

Prof. Yamaguchi : Simply speaking, it was a mechanism which was in place to cool the reactors for a set period of time which had its own isolated power source. At the time of the accident there were 2 Cooling systems installed; “Isolation Condenser System” which operates with the deference in temperature between that of the inside and the outside of the No.1 Reactor, and the “Reactor Core Isolation Cooling System (RCIC)” which is an advanced version of the Isolated Condenser System in the No.2 and No.3 Reactors. Thanks to those mechanisms, in place, I think that, even after the loss of the power resulting from the tsunami they should have been able to properly keep the reactors under control for quite some time. (8 hours for the No.1 Reactor, approx.. 63 hours for the No. 2 reactor and about 32 hours for the No. 3 reactor.)

The coolant systems acted just as they designed to. They each lasted for and performed their duties for their respective times as just mentioned. Engineers also knew that this was the “last fortification” left in place to keep the reactors under control and if they could not get regular operations back under control within these time frames there would be nothing left other than dump water into the reactors. 25 tons of water per hour would be required to manually cool down the core in reactor No.1. However, the freshwater stored in the water tank was not sufficient enough. The only readily available sufficient quantity of water was that of the sea. Thus, there was no choice other than to use that sea water to cool down the violent core. (Reactor Pressure Vessel: RPV).

Note: The Pressure Vessel and piping Structure of the No.1 Reactor of the Fukushima No.1 Power Plant. The RCIC was implemented instead of the IC in the No.2 and No.3 reactors. All of these reactors have the ability to function without external power sources. (Provided by Professor Yamaguchi)
It is a click of the image and a zoom.

Please take note that any information in this article may not be current at this time.