Saturday, March 12, 2011

America's Nuclear Industry - How Earthquake Proof Is It?

Updated April 2016

With the advent of global climate change, nuclear has looked like a clear winner when it comes to cutting greenhouse gas emissions.  With that in mind, let’s take a brief look at the nuclear power situation in the United States and the relationship between nuclear power plants and seismic activity.

The website of the United States Nuclear Regulatory Commission (NRC) contains a wealth of information about the American nuclear industry.  The NRC was founded in January 1975 primarily to focus attention on issues relating to the protection of public health and safety.  They have put into practice standards that are in place to protect the general public from hazardous levels of radiation.  The 1979 Three Mile Island accident and near meltdown was a wake up call for the nuclear industry; this incident caused the NRC to place greater emphasis on operator training and emergency planning.

Let’s start with a map and a list showing the locations of operating nuclear power reactors:

I actually found it rather surprising how many reactors there are and how many of them are located on the east coast of the United States.  In total, there are 104 reactors that are licensed to operate, all of them located in the continental United States and the vast majority of them in the eastern half of the country.

In addition, there are 32 operating nuclear research and test reactors and an additional 9 regulated nuclear research and test reactors located throughout the continental United States, most of which are located at colleges and universities.  These reactors are primarily used for research, training and development and contribute to many fields of science including geology, chemistry, medicine, physics, biology and archeology.  The 9 non-operating reactors are currently undergoing decommissioning and have had their licenses amended to allow possession of radioactive material only.   Here is a map showing the location of research and test reactors:

Now, let’s look at information from the United States Geological Survey (USGS).  The USGS has a National Seismic Hazard Mapping Project, a group of scientists that study earthquakes with the goal of reducing earthquake hazards in the United States.  This is particularly critical because earthquakes pose a significant risk for 75 million Americans.

From their research, the USGS has created a series of maps showing the probability of earthquakes of varying magnitudes.  From the list of maps they have created, I have selected the maps showing peak ground acceleration, a measure of the acceleration (or motion) of the ground during an earthquake.  This is an important parameter that must be considered during the engineering design phase of various structures such as roads, bridges, buildings and, for the purposes of this posting, nuclear power plants.  These maps also were created using various probabilities, for example, the 2 percent in 50 year probability of exceedance, the 5 percent in 50 year probability of exceedance and the 10 percent in 50 year probability of exceedance.  The higher the percentage level of probability, the more likely that the peak ground acceleration will be exceeded during an earthquake over a 50 year period.  When looking at the 2 percent in 50 year map, the map emphasizes less likely events (i.e. there is only a 2 percent chance of the peak ground acceleration being exceeded over a 50 year period) meaning that large magnitude earthquakes with large ground motions are more likely to show up.  When looking at the 10 percent in 50 year map, the map emphasizes small magnitude earthquakes with small ground motions.

Here is a map showing the peak ground acceleration 10 percent in 50 year map (shows smaller and more likely earthquakes):

Here is a map showing the peak ground acceleration 2 percent in 50 year map (shows larger  and less likely earthquakes):

Notice how the areas along the eastern seaboard show up as potentially seismically active, particularly through Georgia and the northeast, especially on the 2 percent in 50 year map?  While the risk is far lower than for the western United States, the risk of seismically significant activity still exists.  If you look back at the NRC map, there are a large number of nuclear reactors throughout this area.  As well, the junction of the states of Arkansas, Tennessee and Missouri appears to have potential for seismic activity; these states are also the home to several nuclear reactors.  I certainly realize that prior to the construction of nuclear power plants that engineers extensively study the risk of ground movement, however, all risks can’t be quantified and the risk of significant seismic activity is never zero in historically seismically active areas.

While the likelihood of a significant and highly damaging earthquake is unlikely for many of the areas where reactors are operating, my posting of yesterday shows that the risk of a rather major tsunami along the eastern seaboard of the United States does exist.  From the NRC database, reactors in Florida, North Carolina and Massachusetts, among others, are very close to sea level and very close to open water.  From the recent events in Japan, we can see that even though backup power generation was in place to prevent reactors from overheating if power from the grid was not otherwise available, that tsunamis can have a very detrimental impact on the operation of critically needed backup diesel generators.  While we cannot plan for every contingency, let's hope that the operators of nuclear reactors in the United States that are located very close to sea level have learned an important lesson from the Japanese experience.


  1. I don't understand why, given the high likelihood of earthquakes near Japan, that the diesel generators weren't located / sized / ruggedized / protected against the effects of a tsunami. It just seems like such an easy thing to predict. And if the generators had worked properly, this would have been (almost) a "nevermind" and a fantastic show for the nuclear industry that it *could* survive an 8.9 magnitude quake.

    Keep in mind, there are 52 operating commercial nuclear power plants in Japan. The attention is only focused on 7 of them; the other 45 have handled the incident well. (I fully realize that it only takes one failure to really screw things up, though.)

    But you raise a good point about siting reactors on fault zones or in tsunami-vulnerable regions. You may be particularly interested in Diablo Canyon, in California:

    It's AT sea level, on the California coast.

  2. TheEngineer - While the warning wasn't about the diesel generators, there was a warning about the earthquakes and the nuclear power plants - by none other than a member of the safety panel that redesigned the guidelines in regards to earthquakes in 2007:

    He quit the panel near the end because no one was listening to him.

    As to why, the real reason is almost always $$$. This is a big motivator to not listen to people who warn about things that's going to put a kink in your plans. Sure, sometimes people are just being crackpots and they'll always be someone who is warning about everything imaginable. But that doesn't seem to be the case here.

    Of course, now it's going to cost some SERIOUS money. But that's always how it goes. It's much easier to dismiss something that hasn't happened yet and not get criticized for it than to take the warnings, make things "right" and then never have the problem occur. People don't really celebrate your decision because it's hard to quantify something that didn't happen because you avoided it.

  3. The back up Gen's placement was the big mistake,but i can see why they put them there, fumes and cooling. The ODP was 26 years,pushing 40 is asking for it.

  4. Some of the US plants are pushing over forty and the very pro-business-as-usual NRC just granted Vermont Yankee an extension!!!

    The NRC has refused to look at a worst case accident scenario that has more than one thing going wrong. In Ct (MIllstone 2 -around 1990) the spent fuel pool containing over 3 reactors worth of spent fuel (I like to call it enriched plutonium ore) had a Loss Of Coolant after receiving a full core download. They were rushing to replace the steam generator before anyone from the organizations fighting the siting of a " Low Level" radioactive waste dump took notice. They were also refusing to revisit their calculations on the ability of the pool to remain subcritical with a full core download in addition to the tree cores already in the pool. Then they lost power and came within minutes of a pool boiloff.

    Once the metal that contains the plutonium enriched fuel pellets becomes exposed and overheats it can be expected to catch fire and burn out releasing the pellets. These pellets would form a critical mass at the bottom of the pool. More heat and continuous release of radioactive particles and gases would be expected. From the water boiling off so fast, a steam explosion would blow apart the cement building surrounding the pool. We were aware of this scenario prior to the LOC in the pool. We envisioned the loss of coolant to a criticality in the pool, and not to the malfuncitong of pumps, generator, and human error in initiating the tranfer of cooling from the reactor ( now empty) to the pool.

    The method they used ( and still use) to prevent a criticality in the waste is to separate the unfissioned fuel and fissioned (plutonium ore) assemblies with borated plates of rubberlike material. Our pending challenge to a license change requested by the company to rearrange their spent fuel pool to account for some mathmatical errors of years gone by may have slowed this transfer down by a few days, but on the forth of July they moved it. We did not see a rise in our gieger counters, and felt the worst was past for that day, but learned the next day from a reporter that an accident had occured in the pool...continued

  5. continued:
    During the weeks preceding the full core download we were meeting with NU and discussing our worst fears, The company ( Northeast Utilities) said that if all went wrong they could always use the fire department to pump sea water into the pool. If it were not for a worker who just happened upon water in the reactor building floor and called the control room, water would have continued to drain out of the pool, and more seriously no cooling water would have been supplied in time to prevent the boiloff. Something else went very right that also saved the day. The main current was restored and the normal cooling pumps came on. Without the worker, and the timely restoration of power we would have seen a meltdown and probably a mass criticality in that pool. New London, CT as ground zero and Boston and NYC within 150 miles.depending on the direction of the wind until they could seal it...days...weeks

    If I remember correctly it went like this: The had lost utility power and a one of the two back up generators for the pool was out for maintenance, and the other failed to start immediately. When it finally did start two pumps and one wouldn't pump and the other' would not cool! They then activated from the control room the Emergency Core Cooling System which was not needed for the reactor since all the fuel was in the pool. But they failed to insure a valve was closed that had to be opened earlier to transfer the fuel into the pool. If a worker just didn't happen to be going through the reactor building when he did, and the power was not restored to the main pumps when it did, ............
    I had alerted the AG that if the pool blew I wanted the treasury at my disposal to clean up the mess and compensate those that survived.

    Now here is the clincher: the NRC accepted the utility's report and nothing more was done ecept to report that there was an event. The report did not disclose the scenario that caused the problem, nor how close they came to a meltdown in the pool, and that it was corrected only because a worker was somewhere where he was not required or asked to go, and that lady luck returned power to the plant just in the nick of time.

    The NRC does not work for the people, it works for the military's and DOE's agenda (formerly AEC) They are in the business of keeping the wool over our eyes. Nuclear energy is only efficient at what it only can do, make plutonium.

  6. Government agencies have been measuring these levels and reporting that you don’t have to worry as everything is under complete control. However, the scientists and university students are demonstrating a different version. They are actually measuring high levels of toxic radiation in our food and water supply that are hazardous to human health. And they are increasing every day. We already that what the “experts” have told us is just not true.

    They told us in the middle of March that we had nothing to worry about with the Japanese Nuclear Reactor possibly leaking or exploding, that they had it under complete control. Those same people that were hiding the truth now want us to believe that “radiation poisoning” should be nothing to worry about for the average person.” I don’t buy it! I don't think they are really after the best interests of the "average person", and if you value you and your families health, you shouldn’t buy it either. I’d much prefer to Detect Radiation and be safe rather than sick or dead!

  7. This is a very unfortunate event. We've had 50 years of history showing us severe catastrophes that nuclear radiation can cause. I've even heard that some brave Japanese workers have given their lives to help clean up the mess. I salute them for their bravery in a toxic situation. I am also praying for this mess to be dissipated quickly and not harm many people.

    Herbs should be our first line of protection against radiation and heavy metal poisoning (cesium 137 and plutonium are heavy metals.)I hope people do take some precautions so they don't get sick though. Like using some simple and common Herbs for Radiation exposure and protection.

  8. MBS, are you an expert in radiation physics? How much do you understand about measuring alpha, beta and gamma radiation? If the link you share "Detect Radiation" is the extent of your understanding than you you should keep you thoughts to yourself. It is this kind of nonsense that perpetuates the misundersatanding that permeates the nuclear industry. Do you REALLY believe that you can obtain a good measurement of the small amounts of radiation that are being transported to the US by a keychain device? This is more hilarious than the jokesters that used to sell tonics from the back of wagons. If you don't know what you are talking about keep it to yourself!

  9. Age of plant is irrelevant.

    The NRC says that the plants in the US are in danger also.

    The NRC just chooses to give these risks a really low probability so it can claim safety.

    All of the Spent Fuel Pools at all plants, old or new, have risks.

    Statistics are just way off - and Fukushima just proves that an event rated as 1 in 10000000000 can and will happen.

    So stop congratulating any plant for surviving not too badly in the inevitable weather.

    Stop blaming age, older design, lack of maintenance etc. none of those caused this.

    Just lies and statistics!

  10. There's also the threat of the Cumbre Vieja volcano in the Canary Islands:

  11. Ameren plans to seek a license that would allow it to build and operate up to five nuclear reactors.

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