Message from U.S. to U.S. Citizens in Japan

Under the guidelines for public safety that would be used in the United States under similar circumstances, the NRC believes it is appropriate for U.S. residents within 50 miles of the Fukushima reactors to evacuate.

In making protective action recommendations, the NRC takes into account a variety of factors that include weather, wind direction and speed, and the status of the problem at the reactors. Here is a link to results of two sets of computer calculations used to support the NRC recommendations:

In other news, the U.S. Embassy continues to update American citizens as the situation develops. U.S. citizens in need of emergency assistance should send an e-mail to with detailed information about their location and contact information.

Eliot Brenner
Public Affairs Director

Author: Moderator

Public Affairs Officer for the U.S. Nuclear Regulatory Commission

19 thoughts on “Message from U.S. to U.S. Citizens in Japan”

  1. I can understand the evacuation within the 50 mile radius,but for people on the west coast of the U.S. to get excited seems a bit of an overreaction.

  2. I also would like to comment on the NRC’s information. While I don’t share the previous poster’s expectations, I think the NRC is doing a disservice to the public by posting the hypothetical dose evaluations they’ve made without a shred of information as to what the assumptions were that they were based on. I’m a radiation protection professional and have worked at nuclear plants similar to these. I understand that under the circumstances, expecting to have isodose maps around the sites is a pipe dream (it would put people at risk and tie up critical resources for no good reason). The situation is dynamic, stressful, dangerous and uncertain. Also, the infrastructure with which to mount serious environmental monitoring efforts does not exist, and these measurements are not a priority. The priority is to get electricity to these plants and get the cooling stabilized. But, the NRC took the time to sit down and do dose modeling for some release scenarios. They have provided the results of the modeling but have told us nothing about the assumptions of releases under which they were produced. In effect, they did give us an answer to a “what if” scenario, but they didn’t tell us what the scenario was. These numbers are pretty scary when there’s no context to put them in. Please, NRC, explain the INPUT that generated your output.

  3. PLEASE DON’T HIDE OR MINIMIZE EXPOSURE LEVEL ESTIMATES FOR WEST COAST!! I have 3 children under 6 years old and I can send them to live with family in Minnesota if you give our family notice and don’t hide information.
    Given the documented leaks and the current risk of full meltdown in at least one reactor, as well as the scientifically known 7 day direct wind patterns from Japan to Northern California, can a NRC scientist please post the official Plume computer data models showing wind patterns and calculated atmospheric dispersion with full radation exposure calculations?
    Please do this using the same, clear language and data as the NRC Advisory to US Citizens living in Japan, WITH SPECIFIC EXPOSURE ESTIMATES. Even if these are low, it would be useful to have transparency on this issue.
    Also, could the NRC please create a credible peer reviewed site with Plume models and exposure estimates so that other credable scientists from major government agencies and universities can comment with full public transparency?

  4. With respect to the calculations, what exactly is meant by maximum dose? Are doses for locations in the ocean excluded? I am trying to make sense why many of the dose values seem to drop off by a factor of about 2 for every ten miles for one set of calculations and seem to level off after about 10 miles for the other. My guess it has something to do with differences in the forecast meteorological conditions. Is it possible to provide any more insight as to what was assumed for these two hypothetical release scenarios? For example, what would be the duration for these release scenarios?

  5. What about air travel between Asia and US? On my Seattle to Taiwan flight, we seemed to travel down the spine of Japan, but I did not look at the map that carefully. If significant radiation is release, will air travel be impacted? Should I leave for home ASAP? Could you please provide altitude info in your plume modeling?

    I agree with the above comment. I saw the link to the NRC from the CDC WEB page and am disappointed there isn’t more here. I am in Vietnam on work travel and have been seeking reliable info. The NRC should step up as the authority! I have found the information you have provided as VERY helpful. Now is your hour to shine! Thank you

  6. I am sitting at my house in the U.S.A. looking at the issues you are facing with your powerplants. I see that you are using the helicopters to try and cool down the spent rods. My question or comment is this: You have pumpers on site to use the water cannons. Why dont you use the Helicopters to place a rigid temporary pipe much like a candy cane into the affected area. I am sure your fire pumpers could pump water up to a certain head. Once you have a constant supply of cooling water, you can refocus your efforts to containing the other issues. I know nothing about nuclear powerplants but I do understand the fundimentals of plumbing. Pull from the ocean with a suction line. supply to the candycane side of pipe via supply side of fire pumper. All you will need to do is make sure you don´t run out of fuel for the pumper. I know this is a simple thought from a simple person but sometimes people can over engineer something without seeking the obvious.


  7. While I appreciate the calculations provided to support the PAG, I wish there was more information given regarding the assumptions used to derive these doses. Information such as the assumed source term in Ci/s along with an assumed release height and release duration would be helpful. In the absence of this information it is difficult to determine if these dose calculations are credible or entirley unrealistic. As presented they seem unnecessarily alarming and of little techical value.

  8. In a webcast with investors this week a South Carolina utility official assured investment analysts that there would be no way that anyone could challenge the construction of a new nuclear plant in S.C. through the NRC…even though the NRC hearing is not expected to take place until the fall of this year. How can this be the case? In light of what we are witnessing…how can the NRC not allow the public to weigh in and possibly force reconsideration of new nuclear plant construction? Reportedly, SC already has more nuclear power than any other state (per capita) and we’re the nation’s nuclear dumping ground for ‘low level” nuclear waste. How can the NRC process be a done deal for this plant – so much so that the utility CEO (see transcript below) can say without any doubt whatsoever that nothing will affect the outcome of the NRC hearing next autumn?
    (Transcript from March 15 Webcast –

    Ashar Khan – Visium – Analyst
    I just wanted to check, Kevin, can you tell us if somebody starts a legal suit or something to stop or review all of this? What could happen? Do they have any power to delay some of these new plants?
    Kevin Marsh – SCANA – President, COO
    I certainly couldn’t give you accurate speculation on what the legal community would end up with if they tried to file some sort of a suit. But we believe we have followed all of the rules and regulations and we have been through numerous reviews. We’re scheduled to go through the hearing at the NRC once they are ready to go through that process. We have no intervention approved in those hearings. But I think we have done everything we know to do to prepare for that process. If someone were to try to step in that in some sort of legal maneuver, we would certainly respond to that, but I just could not speculate today on how that might come.I don’t know which form it might come in or how we would respond. I’m certain that we would respond, I think the industry would respond based on the schedule we’ve had and the number of reviews and evaluations we’ve had for these new plant designs to this point.
    Ashar Khan – Visium – Analyst
    Okay. So I guess their best chance would be at the NRC hearing, right? The NRC hearings are to occur what? In the fall, am I right?
    Kevin Marsh – SCANA – President, COO
    The Commission will have to set that date once they get the final environmental impact statement and the final safety evaluation report, but there has been — we’ve already set the tone of those hearings so that there’s no intervention that has been approved in those hearings.
    Ashar Khan – Visium – Analyst
    Okay. So they have already decided who could participate in those hearings? So it is too late?
    Kevin Marsh – SCANA – President, COO
    That’s correct. Those hearings are uncontested.

  9. Agreed! It is the responsibility of our nuclear industries and oversite bodies here in the US to communicate and educate in a situation such as this. People fear what they don’t understand and the lack of communication at a level that someone not in the industry can understand is simply validating the voice of the anti-nuclear special interest groups which is biased at best.

  10. I have wondered why some fellow conservatives want to get rid of the DOE. Now I tend to agree – they don’t really do anything! They are the ones who should be providing spokespeople with balanced insight, rather than NRC. The NRC is an “independent, regulatory body” and, as such, is much more sensitive to issues of political correctness. DOE should take the lead, gathering information from NRC and demonstrating that they have a grasp of the technical and human issues that confront the nation and globe.

  11. I agree with the comment. I understand that it is highly sensitive situation for the NRC to provide information about another county reactor. I visited your site several times to find basic information and found several reports that helped me explain to my children and friends what could be going on. The NRC can do a better job by providing more information to the public as it becomes available from Japan (at least translated). You have to tailor it to balance the objectives of knowing while maintaining sovereignty and accuracy.

  12. The technical chart that you have posted to confirm that citizens should evacuate within the 50 mile zone is VERY confusing. Could you clarify for the layman?
    Thank you.

  13. Without the underlying assumptions, the source term used for the calculations these values do not provide a great deal of information. What assumptions were made and what was the resulting source term used for the the calculations?

  14. Given that there currently is a map, showing incorrect Fallout dispersion areas circulating around the internet.

    I call on the NRC to show the American public an accurate map of dispersion, one that factors in real time weather readings, in order that the public be able to employ educated and appropriate reactions.

  15. The computer model information is quite informative and detailed but by itself it is hard to interpret by a professional scientist without further clarifying information.
    It has not been made clear whether these constitute worst case estimates or are based on current condition estimates.

    In my field, I expect to see estimates of systematic uncertainties and confidence levels and
    a description of model parameters that have been varied.

    I conclude from the figures that there is a scenario in which a 50 mile evacuation zone is
    more than justified under current US regulations, but the information tells me little about the likelihood of such a scenario or on the range of possibilities, and the predicted doses at distances beyond 50 miles.

  16. Excellent post by NRC. Thanks for providing a link to your calculations. Recognizing that dose projections models may have a wide variation in results, did you include the decay time from scram to the time of apparent release from Unit 2? The decay may have been about 24 hours or more.
    Thanks again, NRC is doing a better job of communicating.

  17. What is the basis for this hypothetical release? The projections show lots of high dose numbers, but what are the assumptions of the calculation? I find it extremely hard to believe that these numbers are even remotely credible.

  18. I know that we have excellent people at the Commission.

    The recent events in Japan really need the Commission to be far more proactive in communicating with the public particularly US Citizens in Japan. The mis-information on news networks is despicable. If there was a lesson learned from TMI, it is to have lots of information and spokespeople to interpret it for the public. None of this is happening within our government. There are links below for EPA, The White House, The DOE, etc. But much information on these sites is negligible, dated to non-existent as well as on this site.

    The lack of information needs rapid corrective action.

    This site could be a great place to do the following:
    1). Have dosimetric isopleths displayed around the plant with known rad levels as well as at distances to Tokyo and information on nuclides; this can be updated hourly with some explanatory information on dose/ biological effects as well as simple graphics;
    2). Basic physical descriptions of what is going on at the plant and options being taken by TEPCO and/or GOJ as well as timelines;
    3). Some ‘whati if’ scenarios and liklihood;
    4). Specific Protective Actions at distances to Tokyo and why.

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