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Nuclear Power/west coast fukushima radiation


Hello Dr. Nelson

I'm Jay.  I'm not sure if you are able to comment on this but i am planning to relocate to Los Angeles in December and am now a bit concerned about the effects or potential effects of the fukushima nuclear disaster.  I read this article below and now have reservations about moving there. I also heard that thyroid cancers are higher now on the west coast.  I would appreciate any insight on this,  thank you



OK, I'm an expert on this.  A real one, with an understanding of what the numbers actually mean and access to all the fanciest weather dispersion models and extensive knowledge of the nuclear physics involved.

The numbers in this blog you read are wrong and completely misrepresent what's going on.  Not just wrong or "a little misleading," but massively wrong by orders of magnitude.  I'm not sure how this stuff gets published and spread around, but fear is a tremendous motivator.  Keep in mind, I have no vested personal interest in any nuclear power entity, I'd definitely rather see all the old reactors replaced with either solar (where possible) or meltdown-proof Gen IV designs at a minimum.  I also currently live in Hawai'i, and if I thought for a second that radioactive material was spreading all the way to California then I'd obviously be a huge heap more trouble and would have never moved here.

Now that that is out of the way, I'm not going to address the blog itself for a few good reasons.  It actually posits that California could get higher levels of contamination than the coast of Japan.  That's so physically impossible I can't begin to tell you how wrong it is.  It also implies that no one has done any monitoring of any kind of the water.  That's ridiculous, I personally know scientists who have been out in that water taking samples for the last few years.  No one does it better than Wood's Hole Oceanographic Institute.  OK, so I addressed it a little bit.

I'm going to link you to an article from those guys on detectable levels of radiation, but before I do I need to put it in a little context for people without decades of experience working with radioactive material and/or who are perhaps not perfectly clear on the difference between radioactive material and radiation.  What is hot, and what is not?  I'll attach a little graphic that I made, so see attached.  Levels of radioactivity for various common things (irradiator rods and welding cameras on the "hot" end, air closer to the "barely measurable" end).  So by counting for a really long time, especially underground, we can measure stuff that's way less radioactive than typical air.  Measurable.  Hot?  No.

So here's that article:

A little post-article analysis.  1.4 Bq/m^3 of seawter for 134Cs is not just pretty tiny, it's nearly impossible to measure (I told you the Wood's Hole guys were good).  That's over a metric ton of water.  For comparison, I've got (between the natural carbon and potassium in my body) enough radioactive material to have an activity of 8000 Bq.  As a not-small guy (I'm about 100 kg, so about 10% of a metric ton) that simply scales with mass.  If they were to measure a human being, the typical human being contains 80,000 Bq worth of naturally-occurring 14C and 40K.  No way around it.  Even accounting for the 5.8 Bq/m^3 of 137Cs that they found, that's still less than 0.0001 times as radioactive as you or I are naturally.  It's an impressive measurement, the counting must have taken absolutely forever to do.

To put that another way...compared to the cesium they measured, the air you're breathing right now is more radioactive (naturally-occurring makes no difference) and far more damaging (internal alpha contamination from radon).

Further, having been trained in the medical effects of ionizing radiation, I can tell you that the human body can withstand an absolutely stunning amount of radiation (compared to what we're talking about here) before effects become measurable even on a statistical level (requiring thousands of people to be measured).  It's a well-studied subject, people go for medical scans that will give you quite a bit of radioactive material.  Clear images require it.

In short, if you move to California, definitely be concerned.  The sun there is bright, shines all the time.  So wear sunscreen.  Stuff from Fukushima?  Easy to believe if you know nothing about the numbers, but once you do you realize that it's not just not in the same zip code as UV from sun damaging your's not on the same planet.  Enjoy the sushi.  Worry about the important things.  Sunscreen.

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Dr. Stephen O. Nelson


I was at a branch of the University of Texas of the Permian Basin for seven years working on an advanced nuclear reactor. Generation IV nuclear reactors. Radiation safety. Nuclear fusion. Since moved into government nuclear work.


Drew the laboratory design for a Generation IV nuclear research reactor Doctoral research on stellar nuclear fusion reactions if your question is on fusion power.

Ph.D. in physics (nuclear physics), Duke University. Taught physics, radiation safety, and nuclear engineering courses at UTPB for 7 years before moving into government work.

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