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. Zanzibar

    No nuclear power plants are safe. There will always be the one thatll have problems. Lets face it, if there were no Nuclear Power plant there where the earthquake happened, noone would be sweating now. They cost Billions to build, that money should be invested into cleaner energy.

    March 12, 2011 at 10:32 am | Report abuse |
    • Goodbye

      No nuclear plants = no US Navy (the US Navy is operating ~100 reactors currently)

      I enjoy how the one report I've seen that doesn't depict this as an "end-of-the-world" scenario must be total BS according to several of you. Excellent. Please look at some actual websites that know something about nuclear power.

      March 12, 2011 at 11:28 am | Report abuse |
  2. Dreamer96

    From what I have heard the rods were put back in, so a total core meltdown is not a real problem, but the diesel backup generators failed for some reason and they had limted or no power for their water cooling pumps. They fell back on batteries which are very limited in the time they can supply power. The temperature of the core could be very high and with limited circulation of the cooling water you will build up alot of steam in the reactor metal core dome. This metal core dome is suppose to still be intact. They can still contain the situation it they get the cooling system running right.

    March 12, 2011 at 10:36 am | Report abuse |
    • Mike Hansford

      Rods being inserted won't help if there is no cooling to the core. From what I've read so far, don't think containment has been breached. An ancillary building exploded, which could still be a big deal. A core meltdown doesn't mean the end of the world. It happened at Three Mile Island, and the second plant at that site is still operating. Nothing like a disaster to bring out the hysterical people that know very little of what they are talking about. Let's see what happens, . . . and deal with it.

      March 12, 2011 at 7:53 pm | Report abuse |
    • Dreamer96

      Yes I agree with you, but with the rods in, the heat drops to 10 percent, after 24 hours it's down to 5 percent. Yes it sounds like the containment dome is still intact and the metal reactor core dome is intact. The outside building, the metal shell ,or the pop can blew up because they pumped sea water into the metal dome, and steam exscaped to the containment dome and then to the pop can. The steam had hydrogen gas and oxygen, you know H2O. The hydrogen and oxygen blew up. boom. Now the reactor will never be used again because they put seawater in it. That reactor never going to be used again no matter what else happens.

      March 12, 2011 at 8:31 pm | Report abuse |
  3. Dan

    Whoever said solar is the answer and nuclear isn't has been out in the sun too long.

    March 12, 2011 at 10:38 am | Report abuse |
  4. BlueNorange

    i love they they try to cover everything up similar to Chernobyl obviously this reactor didnt go yet.. But yes buddy it is leaking!

    March 12, 2011 at 10:46 am | Report abuse |
  5. Guru

    CNN get out there with your own monitoring equipment, lets get to facts, not what the govt is telling us.

    March 12, 2011 at 11:01 am | Report abuse |
  6. Ruck

    Sure, if there were no nukes nobody would be sweating... well said. I'm sure the mayhem of an 8.9 earthquake and 30 ft tsunami wouldn't be annoying anyone today whatsover, just those frustrating reactors! Of course, the oil refinery that has to burn out of control until the oil is consumed is of no importance (no toxic and highly carcenigic material in those exhaust streams). Not to mention the dam that collapsed after the quake, apparently the reactors are the ONLY power plants in the worst areas affected that are still standing. Your solar panels would be swept out to sea along with any windmills adding to the wreckage. A whole nation is in crisis mode and everyone's worried about a couple reactors that are harming nobody. Everyone loves a good show I guess.

    March 12, 2011 at 11:01 am | Report abuse |
  7. Ruck

    BTW to all, Chernobyl used a graphite core to enhance the Plutonium production of it's reactor (it was a duel production and electric plant, not the best design but it made sense to the Soviets at the time). Graphite is highly combustible when exposed to oxygen at high temperatures... ergo big fire under nuclear core, not smart. We don't build electric power reactors in this manner for precisely this reason. Oh yes, Chernobyl had NO containment vessel either, brilliant. The fearsome meltdown everyone is dreading... a hunk of hot heavy metal sitting on the floor, no explosion in the reactor because any hydrogen is vented out- ala the building explosion seen earlier. Seems the engineers did think this through once upon a time...

    March 12, 2011 at 11:08 am | Report abuse |

    Re Safety of plants in Europe: Windscale in the UK was the first serious nuclear plant failure many years ago, long before Three Mile Island in the US. The UK was able to downplay how serious Windscale was. By the time all the details and inquiries were complted no one wanted to know any more.

    March 12, 2011 at 11:27 am | Report abuse |
  9. david campbell

    Earthquake resistant but to 8.9? Not tsunami resistant. The water shut down the diesel generators that pump the water to cool the core. We have had radioactive leakage and an explosion. Too volatile for an earthquake zone.

    March 12, 2011 at 11:29 am | Report abuse |
  10. Philip

    Hard to believe a nuclear powerplant could withstand an "10,000 year quake" when their domes can barely take 80psi. Really. After the protective dome is finished, it must be pressure-tested. This is done using several very larger air compressors, like a dozen or so Atlas-Copco 1200cfm units. We pressurize the dome in stages, starting out by pressurizing the dome to around 50 psi and letting it sit for a few days. If the pressure holds and there are no leaks, we increase the pressure and so on...example: The Brown&Root plant near Granbury/Cleburn Texas held 74psi and we called it good. (I'd tell you how we went about finding the leaks but you would laugh at me and think I made the whole thing up)

    March 12, 2011 at 11:35 am | Report abuse |
    • attaboy

      im curious, let me know

      March 12, 2011 at 2:14 pm | Report abuse |
  11. engineering1

    think about it..there was an explosion at the plant..the roof caves in, at the reactor that is holding the rods, smoke is seen above the plant, and what do you think is in that smoke, it does not take a rocket scientist to figure out it is radioactive, why else would they evacuate and say the outside of the plant is 10x higher then the normal what about water leakage back into the ocean if there is a crack, and ok put ocean water into reactor to cool it, where is all this circulated heavy water going to go, out the leak back to the ocean.

    March 12, 2011 at 11:36 am | Report abuse |
    • john

      Heavy water? Heavy water is tritium, there is some amount in the water based on neutron interaction, but it is not like heavy water concentrations used in nuclear weapons. The correct term would be radioactively contaminated water that has nuclear byproducts if the fuel rods are breached. Most of those byproducts are metals that would flow into the waste stream and collect on the sea floor near the facility. Ten times higher levels than background are interesting, but not a big issue, however based on the catastr4ophic failure, I give little credence to the report that the levels are rapidly returning to normal.

      March 12, 2011 at 1:09 pm | Report abuse |
    • Frank

      What heavy water? Heavy water is deuterium and it is only used in Canadian reactors – you know, the reactors that when the water leaks out the reactor STOPs. CANDU reactors use heavy water as moderator so they don't need enriched uranium (they were designed to run on "natural" uranium). Reactors in question use regular, "light" water.

      Heavy water is also quite safe (and of course, non-radioactive). A few grams of your body is heavy water. A fraction of all water on planet is D2O – that's where it is concentrated from!! You drink a little bit of that each and every day.

      March 13, 2011 at 1:21 am | Report abuse |
  12. ed bailey

    How can man buid a stress machine with enough whiz to simulate moving the earth 4 inches! We cannot in reality so the rhetoric is a mute point.I have always distrusted engineers because they KNOW IT ALL!

    March 12, 2011 at 11:42 am | Report abuse |
    • sam

      what did you say? i'm sorry, i wasn't able to hear your mute point.

      March 12, 2011 at 12:26 pm | Report abuse |
    • ed

      > mute point

      It's "moot point", legal term for not relevant, regardless of being true or false

      March 12, 2011 at 1:19 pm | Report abuse |
    • Mark

      You're just jealous because it's plainly obvious that you couldn't engineer a Lego project with detailed instructions, let alone a power plant. Go read "how stuff works" and you might learn a thing or two.

      March 12, 2011 at 5:55 pm | Report abuse |
  13. Philip

    ...and I'd mention what we used to do during those days we were waiting to see if the pressure held, but you would call the cops. he he...bless our hearts oilfield trash. We mean well.

    March 12, 2011 at 11:44 am | Report abuse |
    • MAC ADAM


      March 12, 2011 at 2:46 pm | Report abuse |
  14. ThomasD

    Ya know, Phil, I think Id like to hear some a those stories one day. Then Ill tell ya some stories about our leisure time building Boeing aircraft and why I won't fly.

    March 12, 2011 at 11:48 am | Report abuse |
    • Dreamer96

      I hear you, I love the way they moved the "Smart" people to Chicago, away from any North Korean missile strike, but left the workers. I would like to hear what Philip has to sat too. I was under the impression they tested those domes at about 10 times that psi. It's really scary that being a "professional" really means "professional liar".

      March 12, 2011 at 1:39 pm | Report abuse |
    • Dreamer96

      Well I was gone it's only 200 psi on may domes.

      March 12, 2011 at 1:54 pm | Report abuse |
  15. Philip

    @engineering 1...the rebar in that "roof" of yours is as big around as my arm. They don't "cave in", they crack under pressure. In the near future this will not be a concern because we will all be using Chinese built pelletized reactors. They already make them for about 1/2 the typical price, prefabricated even. Zero percent chance of a meltdown using this civilian model vs. (insert opinion here) chance of our typical military model experiencing a meltdown.

    March 12, 2011 at 11:51 am | Report abuse |
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