Sunday, March 2, 2014

Ammunition as Radiation Shield

Watching the idiots in our government's rule the situation with Ukraine, causes me to ask a useful question. How much thickness of ammunition to you need to provide an adequate radiation shield? As a general rule, the amount of mass determines the effectiveness of radiation shielding.  For example, three feet of earth and two inches of lead are roughly the equivalent in stopping gamma rays.  In both cases, there is roughly a 1/40 diminuation to in the amount of radiation that passes through.  This was for a long time the Civil Defense standard for home radiation shelters.

Because ammunition consists of lead, copper (which is a bit more than half the density of lead), and propellant (which is quite low density), I suspect that ammunition as it is typically sold in case quantities is probably about one-fifth of the density of lead sheet. A traditional survival concern after nuclear war is not only radiation shielding, but also ammunition, primarily for hunting, but secondarily for self defense.  It should be possible to combine these two concerns into a single solution.  In the aftermath of a limited nuclear war, such as the Smart Diplomacy of Obama could easily stumble us into, it would be useful to have both a radiation shielded place to sleep, as well as a stockpile of ammunition.

One of the difficulties is to find a way to stack the ammunition so that is both stable, especially if you must be concerned with a nearby air burst, and at the same time provides sufficient protection from radiation.  If you have a slab foundation house, and are built directly on that foundation, you have the advantage that the earth provides radiation shielding below you.  You only need to build sufficient structure to hold the cases of ammunition so that they form a box or perhaps igloo shape in which you can sleep, or at least wait the one to two weeks required for radiation levels to die down.

Those of us with houses that have a crawl space have a more complicated problem.  Potentially, radioactive fallout they work its way into the crawl space, creating a radiation hazard from below.  This suggests that you would need a ten inch layer of ammunition on the floor before you could construct your ammunition radiation igloo. Conceivably, you could place the layers of ammunition in the crawl space under the area where you intend to stack ammunition to provide radiation shielding.  There is still some radiation exposure between the ammunition in the crawl space and the flooring, but this can be ameliorated by placing ammunition cases where radiation might otherwise comes through the flooring.

Of course, at this point, ammunition is still surprisingly scarce.  This might all be quite academic as a solution.  For those of you with hundreds of pounds of ammunition lying around the house, as must be the case for many of you to explain the enormous sales ammunition these last three years, this might be a possible solution.

I'm experimenting with Microsoft Windows 7.0 and its voice recognition software.  Regular readers may recall that I started using DragonSoft voice recognition software under Windows XP a couple of years ago when I was having some left arm tendonitis problems.  I discovered that Windows 7.0 as voice recognition capab


  1. Hmm...

    I think that dirt would be a lot cheaper and more effective shield. Put it ammunition boxes if you want.

    Also, except at the moment of detonation, near an explosion, radiation shielding is not as big a concern as avoiding breathing or ingesting radioactivity. That means you need an air tight shelter, which ammo isn't going to do for you.

  2. Frankly by the time you'd bought enough ammunition to do a single wall in a shelter big enough to live in for a week or so you could have rented a backhoe and dug yourself a nice half buried little "tornado shelter" AND had enough left to supply you with sufficient self defense and hunting rounds for a reasonable while.

  3. Back in the days of the "neutron bomb",I recall one German bomb shelter lined with sausages. The meat was there to take the heat off of any neutrons that made it through the metal shielding. Builder had to put an inner liner up to stop the hot grease from hurting the occupants.
    The best radiation shielding I've seen use in a shelter is water. One tank inside another with a water-filled gap between them.

  4. It is true that radiation in the air is a big problem, but even then, it is attached to particles. Even being inside an average house, if the HVAC isn't running, will substantially reduce your exposure because there will be only a few particles coming into the house. (They tend to be pretty big.) Radioactive iodine in the air is an issue.

  5. I don't know but if we do get into a nuclear war it might just be better to die. As bad as things are I think the new world would likely be far worse.

    BTW, ever see this Twilight Zone episode? Definitely wouldn't want to be in a population center or anywhere close to one when the sh*t hits the fan.

  6. What StormChaser said.

    Radiation shielding is only important when there is an intense source of radiation nearby - such as a Bomb going off.

    The radioactive debris in fallout produces low intensity emissions that are not a significant danger if one is even a few feet away.

    The real danger from fallout is the radiation that it emits into directly into body tissues when it has been inhaled or ingested (or is in contact with the skin - glow-in-the-dark radium makeup would be a Bad Idea).

  7. Concrete and dirt are far more effective than ammunition, anyway. You need structure to hold the ammo anyway...

    And none of that is relevant unless you're expecting nuclear war on a fairly large scale, which... I'm not.

    (I'm not even expecting a Rogue Nuke scenario, honestly, though it's less unlikely.

    A "dirty bomb" is no significant hazard even if you live in a likely target zone like NYC; stay indoors for a few hours if it's near you, then flee away from the detonation site.)

  8. You don't need direct contact with fallout to be a problem. Beta and gamma rays and neutrons are a problem inside a typical frame house in the event of fallout. The whole focus of the Civil Defense program during the Cold War was to deal not with primary radiation, but secondary radiation from fallout.

    I have a fair amount of confidence that a post-nuclear war society can rebuild. It is not going to be easy, but on the other hand, the left is heavily concentrated in the most likely target zones. This means that who rebuilds the society is most unlikely to repeat the mistakes that we are making today. (Different mistakes instead.)

    Yes, "The Shelter" is a powerful episode. But the experience of Americans with other disasters suggests that we tend to pull together with surprising willingness, as long as the government isn't involved.

  9. @Clayton, You are correct that fallout is a problem without direct contact. I did not mean to imply that you don't need shielding. BUT.. until you prevent direct contact, shielding doesn't do much for you.

    Beta is *not* a problem unless the source gets inside of you. Beta is stopped by skin or a sheet of paper. Gamma and neutrons are much harder to attenuate.

    I agree that a post nuclear society can rebuild. Also, the amount of radiation even from an all out nuclear war is not as bad as most people think. If you spread it evenly across the surface of the earth, it would not be close to a lethal dose.

    In reality, it will be pretty highly concentrated to and downwind of ground bursts.

    Air bursts (such as used against cities) produce no localized fallout - their fallout will be dispersed through the entire northern hemisphere, and also reduced because much of the radiation will die out before it gets back to earth. There was *no* fallout at Hiroshima and Nagasaki, for example.

    As for a dirty bomb, the main hazard is economic. It will render an area uninhabitable for a long time - at least by the modern, radiation-phobic populace.

  10. So what do you think of the voice recognition capabilities of Windows 7 compared to Dragon? I've a friend who uses Dragon on an iPad, but is hampered by the need for a constant internet connection to do so using the IOS version.

  11. Alpha particles will be stopped by paper or skin; beta particles will not.

  12. So far, Windows 7.0 speech recognition is close to being as accurate as Dragon (admittedly, I am comparing Dragon after many hours of use, and it does learn), and the Windows 7.0 speech recognition software is noticeably faster.

  13. So far, Windows 7.0 speech recognition is close to being as accurate as Dragon (admittedly, I am comparing Dragon after many hours of use, and it does learn), and the Windows 7.0 speech recognition software is noticeably faster.

  14. Sorry, you're right about alpha v beta. I've was thinking only of low energy beta (tritium) that is stopped by paper, and over-generalized. I should have remembered that exo-atmospheric nuclear blasts can kill satellites months after the blast from orbiting beta.

  15. I went to your EPA link, because on further thought, I believe that beta is not a significant issue. The site supports that, suggesting thick clothing is sufficient to protect against beta. More than paper, but not by much.

    "Additional covering, for example heavy clothing, is necessary to protect against beta-emitters. Some beta particles can penetrate and burn the skin."

  16. I forget how you turn it ON in windows.

    I also have a sneaking suspicion that Dragon merely puts a new interface on Windows' speech recognition API.

  17. Radiation shielding:

    Gamma rays: protection is proportional to mass/area (between source and target). 1cm lead = 11.3cm water. X-rays are similar, except that being lower energy, much less shielding is required.

    Beta (electrons) - I think similar to gamma, but much less shielding is required. There may be some weird effects.

    Neutrons: Fast neutrons are slowed by collisions with atomic nuclei; the lighter the nucleus, the more the neutron is slowed down and scattered. Hydrogen is best, as it weighs the same as a neutron, and each collision cuts the velocity of the free neutron by about half. Paraffin and polyethylene have a little more hydrogen per volume than water, but water is *much* cheaper. Boron-10 is a good neutron-capture compound, and is about 20% of naturally-occurring boron; it is available cheaply as borax. There's not a lot of hydrogen in ammunition propellants.

    Direct radiation is, as mentioned above, the least of your worries, but the main hazard of fallout radiation would be from that which got inside your house and could be ingested or breathed in. HVAC isn't the only way particulates (and gases!) can get in.