USF Geologist Says Planning Helps Avert Disasters

Design standards for power plants and other facilities should take into account location and past seismic activity.

 

By Barbara Melendez

USF News

 

TAMPA, Fla. (Mar. 17, 2011) – Timothy H. Dixon, who teaches in the University of South Florida’ s Department of Geology, says the safety design for the Fukushima Daiichi nuclear power plant in Japan should have anticipated the size of the earthquake and its attendant tsunami. 

 

If it had, disaster might have been averted.

 

Equating this disaster with the flooding of New Orleans after Hurricane Katrina and BP’s Deepwater Horizon spill in the Gulf of Mexico, Dixon says all three have one thing in common – bad engineering. 

“Some of the current problems in Japan’s nuclear plants are actually strikingly similar to problems experienced in hospitals in New Orleans after Katrina,” he said. “In the latter case, back-up diesel generators were located on ground floors or basements, and were flooded when storm surge over-topped levees.”  Backup power generation systems at the Fukushima-Daiichi complex similarly failed when tsunami waves over-topped sea walls and other flood protection structures.

“A better engineering practice is to place backup generators and their control systems out of harm’s way, for example on the second or even third story of buildings, where they are safe from flood waters. Some of these lessons could apply to Florida, where nuclear plants may be susceptible to hurricane-related storm surge.”   

Another similarity between the two events is that background geology was ignored or downplayed by planners.  In the case of New Orleans, its location on a sinking delta set the stage for disaster.

In Japan’s case, its location in a convergent plate boundary zone, where one plate pushes (subducts) underneath the other, can cause problems.  “Subduction plate boundaries produce Earth’s largest earthquakes, and most tsunamis.  In the last 50 years, this type of plate boundary produced three giant earthquakes: Chile in 1960; Alaska in 1964; and Sumatra in 2004.  All three produced large, devastating tsunamis.

“In terms of energy release, Japan’s event was roughly half the size of the 2004 Sumatra earthquake, the smallest of the big three, so things could have been worse,” Dixon said. 

He suggests using the maximum size of earthquakes on a given type of plate boundary, no matter where it occurs on Earth, as the design standard.  “Sumatra’s 2004 earthquake should have been a wake-up call; giant earthquakes can occur on any subduction zone, and such events will likely be accompanied by very large tsunamis. That should have triggered some re-thinking, and some retrofitting.”

Dixon ultimately recommends better communication between scientists, engineers, business, and government, and long-term planning, particularly in light of anticipated sea level rises and vulnerable populations in coastal areas, an important issue for Florida and many other parts of the world.

Barbara Melendez can be reached at 813-974-4563.