Sumimasen

On March 19th, 2012, I gave a presentation at the Pacific Basin Nuclear Power Conference in Pusan, Korea.

In that presentation I used a slide from the ANS Summer meeting in 2011. This slide indicated that a study by TEPCO in 2006 showed that the recurrence frequency of a tsunami greater than 5.7m was higher than 1/10,000 years.

The slide depicts a recurrence frequency of about 1/400 years.

I was absolutely wrong to use this slide. The information I was given that the slide was about Fukushima Daiichi was incorrect. I did not verify the source of the slide.
The prediction of 1/400 in the slide was based on the location of Yamada in Iwate-ken on the Sanriku coast. Please understand that the coastline in Sanriku is completely different than the coast on the Sendai Plain, where Fukushima Daiichi is located. The coast on Sanriku has a completely different topography and the tsunami effects historically are amplified by the hundreds of small inlets, coves, and bays which proliferate Sanriku and focus the tsunami. For example, even if one believes that the height of the tsunami was 14m, as reported by TEPCO, the height of the tsunami on the Sanriku coast exceeded 26m.

One must be very careful to make probabilistic inferences only from data which comes from comparable sources. The Sanriku Coast is another world in comparison to the Sendai Plain.

I was not careful.

Sumimasen.
Woody

Kondo-sensi

From left to right: Kondo-sensei; Dr. Richard Clegg, Director of Nuclear Lloyd's Register; Jerzy Grynblat, Nuclear Business Manager Lloyd's Register; Popeye

In January, 2012, Woody met with Professor Kondo, the Chairman of the Japan Atomic Energy Commission, a long time friend and colleague. He took his colleagues from Lloyd’s Register to meet Kondo-sensei as they made a tour of Japan.

Kondo-sensei is a great man; he is truly concerned with nuclear risk and safety, and more importantly, he is concerned for the health and happiness of Japanese people.

Dr. Kondo became a Lecturer, in 1970, then an Associate Professor in 1971 at the Department of Nuclear Engineering, The University of Tokyo. After that, he became a Professor at Nuclear Engineering Research Laboratory, The University of Tokyo in 1984.

He moved to the Department of Nuclear Engineering, The University of Tokyo in 1988 and remained there until his retirement in 2004. In addition, he was appointed to the Director, Research Institute for Nuclear Science and Technology, The University of Tokyo from 1999-2003. After he retired from the University of Tokyo, he became the Chairman, Japan Atomic Energy Commission in 2004.

Kondo-sensei is not a bureaucrat.  He is a sharp scientist with a heart of gold.  Given his difficult position, his presentation at the ICONE conference in October 2011 was indeed candid.  Click here to read it.

Tsunami Hazard and Risk Assessment Publication

The Tohoki TsunamiWoody Epstein and Philip Watts have released a new presentation on the Tohoku Tsunami on Tsunami Hazard and Risk Assessment

The presentation includes a probabilistic Tsunami Hazard Simulation of Fukushima Daiichi, an explanation of the new PerfectWave® software, the revelation of how many Japanese nuclear power plants are exposed similarly, and the probability of when this should happen again.  They also address the difference between a Seismic PRA and a Tsunami PRA.

Download as PDF