March 12th, 2011
07:54 AM ET

Expert: Typical nuke plants can take a 10,000-year quake

Many questions remained about Saturday’s explosion at the Fukushima Daiichi nuclear power plant in northeastern Japan. In general, these kinds of facilities are among the most carefully designed and heavily scrutinized structures in the world, said a top civil engineer.

Ron Hamburger, who travels the world studying earthquake-damaged buildings and other structures, says a typical nuclear power plant is designed to withstand earthquakes of the magnitude that only occurs once every 10,000 years.

Friday’s quake was the most powerful to hit the island nation in recorded history, and the tsunami it unleashed traveled across the Pacific Ocean. Reports from the National Institute of Geophysics and Volcanology in Italy estimated the 8.9-magnitude quake shifted the entire planet on its axis by nearly 4 inches (10 centimeters).

Engineers typically design nuclear facilities with very thick walls. “It’s not unusual for the reinforced concrete walls of these structures to be between 3 and 6 feet thick,” Hamburger said Friday before reports surfaced about the Japanese blast. “The reason the walls are that thick is not so much for structural strength, but rather because they use the concrete in part to shield any possible radiation.”

Typically, equipment that’s most critical to safety at these plants has been rigorously tested for earthquake resiliency on so-called “shaking tables.” The equipment being tested – pumps, control valves and electric motors - is attached to the shaking tables - which measure as large as 20 feet by 20 feet. Computers use data from past earthquakes to move the table and the equipment up and down and side-to-side to closely simulate movement from actual quakes.

“The entire design and testing process of these nuclear facilities is designed to withstand the earthquake, shut down safely and contain any radiation hazards,” Hamburger said.

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Filed under: Earthquake • Nuclear • Tsunami
soundoff (121 Responses)
  1. mike

    its just a shame that all wee get are lies when things go wrong and people DIE.

    March 12, 2011 at 5:53 pm | Report abuse |
  2. Dan

    This article doesn't even address the problem.
    They lost power and were unable to cool the reactor. It has nothing to do with the structural integrity of the plant.

    March 12, 2011 at 6:04 pm | Report abuse |
    • Sharon

      I think you're right Dan.

      March 12, 2011 at 6:24 pm | Report abuse |
  3. Rich

    Think people. The containment and the reactor made it through the earthquake just fine. It is the electrical power on site that has failed for some reason. With no forced cooling the reactor heats up and energy enters containment. If pressure in containment was already high when the hydrogen explosion happened then it blew the roof off. Remember, only the roof blew off the rest of the structure is intact. So the real question is what happened to the diesel generators, did they or their output breakers get flooded? I am not too familiar with BWR's, is natural circulation not possible in a BWR?

    Philip, you sound like a contractor that knows just enough to be dangerous and spread propoganda but have no real experience other than running an air compressor. I beg everyone not to listen to his "stories".

    March 12, 2011 at 6:27 pm | Report abuse |
    • Dreamer96

      Yes I have heard them say that the tsunami wave damaged the diesel generaters, but it could be the breakers too. If the wave made it into the backup generator room than the whole system could have fried up. I was worried that the circulation pumps for the cooling system are also electric and if those got wet then they are really screwed. Their is not a way to drive the circulation pumps manually, like a direct motor drive. Hell a fire pumper truck could circulate water but probably could not handle the pressure and would definitely get a dose of radiation. They could helo in a fire truck pumper and use it maybe. Times might be getting desperate

      March 12, 2011 at 6:52 pm | Report abuse |
  4. knightforx

    So how much effort did they put in to design/build this thing, and then they located it close enough to the coast to be affected by a tsunami???

    March 12, 2011 at 6:36 pm | Report abuse |
  5. Allen Wollscheidt

    If nuclear power plant design is so rigorous as is claimed, what on earth is the diesel-electric generator backup (for the cooling-water pumps) doing in a location vulnerable to a tsunami ? ? ? . Answer that one, Nukophiles ! ! !

    I think that this is just another excellent example of commercial penny-pinching at the risk of the plant and worse, the risk of the population ! ! ! . PROFIT NOT PEOPLE ! ! !

    Do YOU trust these people to put a nuclear power plant in YOUR backyard ? ? ? . I certainly do NOT ! ! !

    March 12, 2011 at 6:43 pm | Report abuse |
    • Dreamer96

      Yes that is a very good question, and if it really got shorted out by the wave it was a terrible mistake in the design. I can't believe it either. What idiots, but we don't know for sure what happened to the generators and I bet they will try to keep it secret. Hell, maybe someone stepped outside and left the door open. Fate is like that sometimes.

      March 12, 2011 at 7:01 pm | Report abuse |
    • knightforx

      Just the fact that we're having to talk about it is a huge red flag. Even if someone were to come on here with a "these things are designed to withstand an XYZ tidal wave" I'm not impressed. Why tempt fate to begin with?

      March 12, 2011 at 7:53 pm | Report abuse |
    • jeffrye


      It must be an awful feeling working at that nuke plant. I work at one in Canada and while we use a different technology, it would still be very chaotic relying on safety systems designed in the 70's. From what I can glean from reports, they are now using last ditch efforts to cool the reactor vessel (sea water). Normally, demineralised water is used as it is least corrosive to the pipework and vessels. The cooling pumps that circulated the demin coolling water lost power, possibly due to ground faults caused by the tsunami. The backup diesel generators were also affected, therefore they may have had a limited amount of time on battery (hours). A powerful explosion resulted from the build up of heat withing the reactor vessel due to a loss of cooling and an inability to bleed off steam from the boiling coolant which is demin light water as I mentioned. The fact that they are now handing out Potassium Iodide pills means they are concerned the fuel is going to get so hot that it will melt the metal containing it, hence a meltdown. The potassium iodide pills are given to saturate the thyroid glands of people who could be exposed so they do not receive an uptake of the radioactive iodides from the failed fuel.
      Lets all hope for the best...

      Pretty tough to go through an 8.9 earthquake AND a large do you plan for that double whammy?

      March 12, 2011 at 8:02 pm | Report abuse |
    • a geek named Bob

      1.) It sounds a bit like you are conflating two (or more) different issues. (safety, design, and profits.)
      2.) Given that we can use the byproducts of Nuclear power as a power generation source in its own right for LONG periods of time, I'd say that Nuclear power can be a win-win for the environment.
      3.) Consider that number of deaths from Nuclear Power. Compare it with the deaths from Coal or Oil. No reasonable person would conclude that Coal or Oil is safer. (A slurry pond is a toxic nightmare waiting to happen. Radioactive waste has been used since the mid 50's to power arctic monitors, pacemakers, and later, space probes)
      4.) When we use Nuclear power, we aren't worsening the carbon footprint.

      March 12, 2011 at 8:06 pm | Report abuse |
  6. chuck k.

    the nuclear plants were built to withstand earthquakes up to magnitude 8.5. the earthquake in question is 8.9.
    the .4 in difference is not a matter of decimals- it's more than a thousand times difference in energy released.

    is this the best that americans can do in a disaster? idiocracy at it's most i suppose.

    March 12, 2011 at 7:42 pm | Report abuse |
  7. Lejaune

    I'm sure any modern nuclear plant can withstand the quake itself but the crucial question is how well it can withstand the aftermath (loss of power, loss of coolant, tsunami flood, and etc). I think there is something to be learned for future design of nuclear power plants. Just having an earthquake proof building is obviously not sufficient as shown at this very moment.

    March 12, 2011 at 8:49 pm | Report abuse |
  8. Geoff

    The issue if you actually have read what happened.. the plant did just fine surviving the earthquake.. it shut down as designed... what they weren't prepared for was the tsunami that followed that flooded the emergency backup generators knocking them out. Without the backup power they were unable to cool the reactor leading tot his probelm.

    March 12, 2011 at 8:58 pm | Report abuse |
    • bob

      I guess this is why they are pushing for using Gravity to pump the water in new reactors. much much easier to use and far more resilient.

      March 13, 2011 at 12:19 am | Report abuse |
  9. Michael

    This whole article is beside the point. Whether or not the reactor withstood the earthquake is irrelevant. It was unable to withstand the tsunami. Three reactors are, apparently, now in the process of meltdown.

    March 12, 2011 at 9:12 pm | Report abuse |
  10. Colin

    Chances are that the article used information about some of the most modern/new nuclear reactors to date, so it is correct. With Fukushima Daiichi being about 40 years old and the standards and requirments 40 years ago are nothing compared to the ones we have now, Fukushima Daiichi probably couldn't withstand a 10,000 year-quake.

    March 12, 2011 at 10:38 pm | Report abuse |
  11. Kayti

    No one mentions the nuke workers right next to these reactors working their butts off trying to get this situation under control. They've trained for this, they're paid for this, sure, but no one who has worked in nuclear power ever expects it to occur, since such strict protocols and procedures are always in place. These guys have got to be scared for their families and themselves. No matter what ends up happening at these plants, disaster or otherwise, these people are heroes just as much as the first responders rescuing people out in the flooded and broken streets. However you feel about nuclear power, give some credit to the brave workers at the very least.

    March 12, 2011 at 10:45 pm | Report abuse |
  12. ed Bailey

    When will common sense and the humanity factor rule over profit?

    March 13, 2011 at 12:13 am | Report abuse |
  13. bob

    the article didn't mention that it was the Tsunami that actually caused the cooling system to fail not the earthquake.

    March 13, 2011 at 12:17 am | Report abuse |
  14. Bitlord

    Face it, this merely proves the fission industry lied about 'worst case' since the 9.2 in Alaska in 1964 is already on record as being 'possible' anywhere on the Ring of Fire.
    So, quite simply, with 3 failures, it is quite clear that the utilities lied about their testing and certification.
    That, or the regulatory bodies simply have no idea what is 'bad enough' to be unacceptable.
    Given the presence of 137Cs in the exhaust plume, this is a core melt and pressure vessel leak people, not an H2 'vent'.

    March 13, 2011 at 1:42 am | Report abuse |
  15. engineering101

    its not just a steam cloud, it was a soup of a nuclear operation byproducts...why else do you think they evacauted so far away from the plant.

    March 13, 2011 at 3:19 pm | Report abuse |
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