The American Civil Defense Assoc.: Radiation Issues

The American Civil Defense Association recently posted a blog post about Radiation Issues reposted from their Journal of Civil Defense after many readers had questions regarding North Korea.

The explosion of a nuclear bomb in the city.


The nuclear threat from North Korea has prompted many callers during the past few weeks, asking about the effects and attenuation of radiation.  There is a great deal of misinformation about radiation from fallout. The following old rule of thumb for shelter design still holds true. NBC shelters should have four feet of dirt cover, or three feet of concrete cover to give a minimum PF level of 1,000 from fallout. If a “rainout” should occur, or if the sheltered area is within 1.5 miles of a potential primary target, the shelter will require a minimum of eight to ten feet of cover. Shelter entrances require careful engineering, as most of the radiation exposure will come from these entrance areas.

I recently reviewed a series of articles about Nuclear Weapons Effects, written by Carsten Haaland, of the Oak Ridge national Laboratory. The entire series of articles can be found in our Journal of Civil Defense published in 1990. Some of you may be fortunate enough to still possess these journal articles. I have re-typed, in part, the section on ‘Fallout’ and ‘Rainout’ for this current article.


Carsten M. Haaland, Oak Ridge National Laboratory

 What is Fallout?

Fallout is the radioactive dust that comes back to earth as a result of a nuclear explosion at the surface of the earth, or at an altitude low enough for the fireball to engulf solid materials. Fallout dust may look like sand, ash or crystals, depending on the kind of material engulfed by the fireball. If the material engulfed is ordinary earth or sand the fallout will look like sand, but if the engulfed material contains calcium to the extent found in concrete buildings or coral, the fallout may look like ashes. Large dense particles will descend faster than very small particles. For this reason, fallout particles several hundred miles downwind from a nuclear surface burst will be very small, somewhat like particles in atmospheric pollution, and the nuclear radiation from the fallout will be greatly reduced.

The danger of fallout arises from the intense and highly penetrating nuclear radiation emitted from it, which produces a potentially lethal hazard to people in the vicinity unless they have protection. Large areas, covering hundreds to thousands of square miles, depending on the yield and number of surface detonations, can be poisoned with fallout such that radiation from the contaminated area is hazardous or lethal to an unprotected person passing through or dwelling in the area, for periods of days to weeks after the detonations.

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Preparing for Nuclear Disaster (or not) and N. Korea

Civil defenseFrom Herschel Smith at comes this article discussing Preparing for Nuclear Disaster and dealing with some myths and bad information involved with the same. He also opines about the possibilities (or lack thereof) of nuclear war with North Korea.

Let’s discuss a few things concerning radiation, radioactivity and nuclear events.  If you’re a layman, most articles you will read on these subjects will either be written way above your head, or by people who only pretend to know what they’re talking about because they lack the proper education and experience to speak intelligently.  Even the man who wrote this article on surviving a nuclear attack is in that category.

I could wax haughty and throw words around showing what I know about photon, electron and neutron shielding, the theoretical and mathematical difference between a Rad, Roentgen and a Rem, committed dose equivalent to organs, total effective dose equivalent, albedos, Keff (criticality) calculations, the Boltzmann transport equation and reactor kinetics.  But it would do you precisely no good.  None.  You wouldn’t be one bit better off after having read an article like that than you are right now.  You would have to take an advanced engineering degree or train in the radiological sciences in order to stay with me in such a discussion, and you can’t right now, so that’s that.  Something else needs to be done because the conversation the “journalist” had with that prepper above is off the charts stupid.

Potassium Iodine, or KI, doesn’t stop the thyroid from “absorbing radiation.”  It isn’t a magic radiation pill, regardless of how pepper and survivalist web sites market it.  There is nothing magic about it.  There is a little bit it can do under the right circumstances, and it can’t do anything else.  If you take it – and be aware that taking KI when you don’t need it can lead to severe health problems, especially in the young and old – it will load your thyroid with iodine and prevent the absorption of any more iodine, radioactive or not.  The intent behind this is to prevent radioactive iodine from being absorbed by the thyroid and thus the absorbed radiation dose from such a localized source.

What it doesn’t do is prevent the thyroid from “absorbing radiation.”  The entire whole body, including every organ in your body and the skin (which is treated as an organ by the ICRP) will still attenuate and absorb radiation from external sources, such as immersion in a cloud of radioactive material.  Charged particles (such as betas, or in other words, electrons) can be essentially stopped by clothing, skin and just a little tissue overlying the organs.

You cannot wear enough shielding to stop gammas or neutrons, although being inside a structure deep in the ground could help…

Read the entire article at The Captain’s Journal by clicking here