On Fukushima

As I’m sure anyone reading this aware, this past Friday northeastern Japan suffered from a 9.0 magnitude earth quake off the coast of Miyagi prefecture, and the tsunami that followed. There is mass devastation to the coastal city of Sendai. This is where most of the footage on the news you are viewing comes from.¬† My former residence of Yamagata is somewhat adjacent to Sendai. Thankfully, Yamagata is landlocked and was less effected by the earthquake and not effected by the tsunami. Areas further south such as Tokyo felt the earthquake but received little structural damage. Where I currently live is completely unaffected.

For handy reference

Aftershocks have continued, and another earthquake estimated at 7.0 is predicted. When and where is uncertain.

What is currently taking the forefront in the media is situation with the Fukushima nuclear power plants. These plants went into immediate shutdown during the quake, but the primary and secondary power sources for their cooling systems are offline. There is a great deal of panic, much of it unwarranted, over this situation. Yes, it is matter for concern but something that must be approached with a level head.

The worst of the western media is inflammatory and the best of it is misleading on this issue. In contrast the Japanese government¬† and media are under representing the issue. The result is a lot of misinformation being spread, which only increases worry and panic. I’ve spent the past three days fielding phone calls and e-mails from worried friends and watching as others flee south or out of the country. I am trying to disseminate accurate information and calm people down as best I can. The following are e-mails I have sent regarding the current situation, and why most of us don’t need to worry.


Hello everyone,

I hope you’ll excuse the mass e-mail. There’s been a lot of talk about the Fukushima power plants recently, and even some panic. I would like to take a moment to help separate fact from fiction.

Concern over the nuclear power plants in Fukushima is warranted, and I can’t fault people for acting cautiously. The biggest issue right now is ignorance and misinformation. This shouldn’t be surprising as nuclear power and radiation are complex topics and the average person is not knowledgeable of these things. The result is panic and overreaction.

I benefit from having a friend who works as a nuclear safety engineer for Mitsubishi Heavy Industries. As you can imagine Fukushima is our current hot topic of conversation. There are a couple important points to know.

The first is that even damaged the containment structures around the units greatly reduce the amount of radiation released.

The second is that the type of radiation being released are beta particles from iodine-131 and cesium-137. Beta particles are not far reaching and depend on winds to carry ash to spread the particles. Even with “favorable” winds the amount that would reach outside of Fukushima-ken is so minimal it’s negligible. Beta particles are unable to deeply penetrate tissue, so washing oneself removes radioactive particles. The biggest concern is ingesting something that contains beta particles, so I would avoid eating or drinking anything from Fukushima for a while.

The third is that no X-ray or gamma radiation is emitting from the plant. These forms radiation are electromagnetic, travel far and deeply penetrate tissue. X-ray and gamma radiation are what caused the majority of the initial deaths after the Hiroshima and Nagasaki bombings.

The fourth and final point is that while the radiation emitted outside of the plant is above industry accepted standards, it is still well below the amount that will cause illness, tissue damage or lasting medical issues. Industry standards are exceptionally low specifically for this reason. According to Merck Medical Manuals, the human body can absorb 1000000 microsieverts of radiation before the onset of illness such as vomiting and headache. The highest recorded release of radiation at Fukushima was a 400000 microsieverts spike within the plant (meaning inside the containment structure) that quickly declined. The highest recorded release outside of the plant was 8217 microsieverts per hour. And that was directly outside the plant. Levels have since reduced to well below that. The amount reaching Tokyo is less than a tenth of what Fukushima is exposed to.

It makes sense for Fukushima people to put some distance from the power plants, as long term exposure to even low levels of radiation is probably not the best of things. People in Tokyo and there abouts don’t need to be worried though. You’re not being exposed to much more radiation than normal, and even then the exposure is for brief periods when the wind changes.

These links are good references for what’s going on and what it all means. They’ve been vetted by my nuclear engineer friend as factual and accurate.

A well written lamens summary of radiation, exposure and Fukushima in contrast to Chernobyl, Three Mile Island and the Hiroshima bombing.

Accurate reporting on current events in Fukushima by experts in the industry

An explanation of radiation measurement

An explanation of the effects of radiation exposure, and how much does what.

People outside of Fukushima don’t need to worry about radiation exposure. The kind of radiation coming from Fukushima will only effect the surrounding area. Even then, the amount coming from there is very low. Keep a level head, don’t eat food from Fukushima for a while and you will be fine.


One acquaintance in Tokyo replied with this Reuters article.


I read the recommendation from the US Embassy and the Reuters article and I will agree that the Japanese government is under representing the situation. However, this article is also an example of misinformation coming from the US media. It uses vagueness and misleading language and provides little fact.

First things first, it is recommended by the US government to evacuate to 50 miles outside of the reactors. These reactors are in Okuma, Fukushima and approximately 150 miles north of Tokyo. Tokyo is three times the recommended safe distance.

The emergency workers in question- the ones that could be hit with lethal doses- are emergency workers at the nuclear plant and not emergency or relief workers for the earthquake. Beta particle radiation is more dangerous in proximity, so of course being right at the power plant and even inside the containment structure is going to prove risky.

The section on the UN plume report is worded in a misleading manner. All the report says is that the plume would reach the Aleutian Islands and the US on a certain date, and that radiation from the plume decreases as it travels. This is true. It’s exclusion of radiation levels implies that they will begin very high, which is false.

The warning of wide spread contamination comes from a member of an anti-nuclear group who has obvious bias and no counter statement by a pro-nuclear or nuclear industry member is provided. It is an inflammatory, unbalanced statement with no empirical basis.


Another acquaintance expressed concern of what potentially could happen.


The absolute worst case scenario is the entire containment blows in reactor 2, the wind changes direction and that irradiated steam travels to Tokyo. Even then the individual dose to a person in Tokyo would be 2 mSv. That is nothing. You are exposed to more than that each year simply by being alive.

For reference, a chest X-ray is 0.1 mSv, a mammogram is 0.7 mSv, and a full body scan is 20 mSv. The amount of radiation a person can absorb before physical illness is 1 Sv, or 1000 mSv. Even at 1 Sv of exposure you can recover, meaning non-permanent damage. Increased risk of cancer? Yes, very slightly at about 5%. Guarantee of cancer? No. After exposure to 2 mSv of radiation there are no ill effects and no increased risk of cancer.

The evacuation zone exists in the eventuality that the worst case scenario occurs. They are keeping people as far away as possible in case containment fails, not because of the current situation. If you outside of the evacuation zone, you are safe. If you are in Fukushima, of course you should get out of there. But there is no reason to leave Tokyo save to stop greater panic from spreading and leading to hysteria and rioting.


Hopefully this will help some people understand the situation better. Education is the best weapon against ignorance, and ignorance is our greatest foe right now. There’s a lot of work to be done to recover from the earthquake and this panic is detracting from recovery.


3 responses

  1. Dicky

    Great post Keith. Thoughts are with Japan!

    March 17, 2011 at 9:16 pm

  2. this is a gret post!

    March 19, 2011 at 5:20 pm

  3. Thank you for your great post

    March 20, 2011 at 7:15 am

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