March 28, 2011
Japan Nuclear Establishment Ignored Warnings

Japanese Communist Party legislator Hidekatsu Yoshii warned the Japanese parliament that nuclear reactor backup systems could fail due to natural disaster and lead to core meltdown.

TOKYO—A Japanese lawmaker last year raised in Parliament the possibility that a natural disaster could wipe out a nuclear reactor's backup systems, leading to melting in the core, but the country's top nuclear regulator responded that such a scenario was "practically impossible."

In 2006 Yoshii-san said a tsunami could knock out the diesel back-up generators. If a legislator could figure out the obvious what's the excuse for Tepco and the regulators? Had Yoshii-san been listened to in 2006 preparations to enable back-up generator survival in event of a tsunami could have been carried out. Instead, the Fukushima Dai-Ichi reactors are now worthless, causing huge economic damage, and will take years and huge sums to clean up.

Japanese regulators were very slow to recognize tsunamis as a serious risk to nuclear reactors.

TOKYO — In the country that gave the world the word tsunami, the Japanese nuclear establishment largely disregarded the potentially destructive force of the walls of water. The word did not even appear in government guidelines until 2006, decades after plants — including the Fukushima Daiichi facility that firefighters are still struggling to get under control — began dotting the Japanese coastline.

The guy who was in charge of Fukushima Daiichi in the late 1990s says the idea of a tsunami never crossed his mind. Given the amount of attention Japan has given to tsunami warning systems and facilities to protect civilians from tsunamis this inattention seems inexcusable. Many critics are pointing to the dual role that Japan's Ministry of Economy, Trade and Industry plays as both promoter and regulator of Japan's nuclear power industry. This is reminiscent of the same dual role America's Atomic Energy Commission used to play for the nuclear power industry. After a reactor at Three Mile Island experienced a partial meltdown the AEC was broken up with its regulatory mission going to the Nuclear Regulatory Commission. The same argument is made about India's nuclear power promotion and regulation. But METI is probably worse because lots of top METI officials retire from METI into top electric power industry positions. The relationship between regulator and regulated is too cozy and familiar.

I worry about complacent nuclear regulatory agencies lacking in imagination and captured by industry. Nuclear power requires sustained highly competent regulation. Are governments even capability of the needed level of competence? Seriously.

A move toward newer and much safer reactor designs will be slowed by the Fukushima failures. Regulators will take longer to approve new designs and will spend a lot of time examining existing reactors. Three Mile Island and Chernobyl caused higher nuclear reactor construction costs. Whether that will happen this time around is less obvious. New designs are designed to lower costs and boost safety margins at the same time.

Do you know what Japanese CEOs do doing a crisis? They disappear. The CEO of Tepco has basically gone missing. BP's former CEO Tony Hayward is a champ compared to these guys.

Share |      Randall Parker, 2011 March 28 08:34 PM  Energy Nuclear

AMac said at March 29, 2011 9:00 AM:


Based on that history, Sakai, a senior safety manager at Tokyo Electric, and his research team applied new science to a simple question: What was the chance that an earthquake-generated wave would hit Fukushima? More pressing, what were the odds that it would be larger than the roughly 6-meter (20 feet) wall of water the plant had been designed to handle?
The tsunami that crashed through the Fukushima plant on March 11 was 14 meters high.
Sakai's team determined the Fukushima plant was dead certain to be hit by a tsunami of one or two meters in a 50-year period. They put the risk of a wave of 6 meters or more at around 10 percent over the same time span.
In other words, Tokyo Electric scientists realized as early as 2007 that it was quite possible a giant wave would overwhelm the sea walls and other defenses at Fukushima by surpassing engineering assumptions behind the plant's design that date back to the 1960s.

Fat Man said at March 29, 2011 9:41 AM:

Let the finger pointing begin. This is a particularly useless activity before an official inquest has even begun. Not only do we not know who is responsible, we do not even know what has happened.

"The owl of Minerva spreads its wings only with the falling of the dusk."
Georg Wilhelm Friedrich Hegel (1770–1831)

Lawrence said at March 30, 2011 6:46 AM:

Generally speaking, when doing a probabilistic risk assessment of a nuclear power plant (or a nuclear weapon system), one would be looking to reduce the probability of a catasrophic event to less than 10E-6 during the service life. Flooding out of all on-site back-up electrical power generation at a nuclear power station where any reactor would require continuous coolant circulation by electrically driven pumps would have to be considered potentially catastrophic.

Clearly, a 10 percent chance of a wave topping the Fukushima plant sea wall duirng a 50 year period was way too high to be an acceptable risk without taking other risk reduction actions to reduce this single event probability. Whatever these mitigating actions could have been, they would need to have reduced the probability that all chains of failure events could not exceed 10E-6 over a 50 year span.

This nuclear disaster didn't need to happen. What we have here is a failure of imagination.

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