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Discussion Starter #1 (Edited)
im sorry if this has been posted somewere but i cant find it.

does anyone know the answer to any of these?

1. what is the radation level just after a nuclear strike? ets say at point of impact with the average nuke then.
2. what is the half life of the radioactive material used in modern nukes (when used) so i know how long to hunker down.
3. Any tips on purifing iradiated water. its going to come to that eventualy
4. would it be best to bury a shelter deep underground (if so how deep) or to simply put it just under the surface and radiation shield it?
5. how deep into the ground would an emp charge penertrate? could i shield against it just be sheltering deep?
6. What is the safe radiation level for long term exposure? at what rad level can u leave your shelter and live the rest of your life..safely
and anything else u think would be useful


thanks for the advice
 

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im sorry if this has been posted somewere but i cant find it.

does anyone know the answer to any of these?

1. what is the radation level just after a nuclear strike?
2. what is the half life of the radioactive material used in modern nukes (when used) so i know how long to hunker down.
3. Any tips on purifing iradiated water.
4. would it be best to bury a shelter deep underground (if so how deep) or to simply put it just under the surface and radiation shield it?
5. how deep into the ground would an emp charge penertrate? could i shield against it just be sheltering deep?
6. What is the safe radiation level for long term exposure?
and anything else u think would be useful
thanks for the advice
1. Depends on the strike. You'll need to measure it with a meter, and calculate the decay using the 7/10 method. For each 7 fold, increase in time, you get a 10 fold decrease in rate. There are spreadsheet files available to do the calcs for you.
2. See #1.
3. If the water was in a sealed container, it's fine. Decom the container if it came into contact with fallout before opening it. IF all it recieved was a radiation burst, it's fine. If this is water "in the wild", it will need to be filtered with one of the sub-micron filters to be sure everything it pulled from it. Myself, I wouldn't used any filtered water....
4. Depends on the likelihood of a blast wave hitting it /proximity to the burst, and type of burst likely to be used... air or ground. When in doubt, bury it deep. Utah Shelter Systems, which has had access to government test data on burried shelters, suggests placing it as deep as it is tall. Rounded shelters, such as they construct from culvert type steel, seem to do well with both overpressure and ground shock. YMMV.
6. You'll have to define long term. Certainly not more than 200 Rems.
 

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im sorry if this has been posted somewere but i cant find it.

does anyone know the answer to any of these?

1. what is the radation level just after a nuclear strike? ets say at point of impact with the average nuke then.
2. what is the half life of the radioactive material used in modern nukes (when used) so i know how long to hunker down.
3. Any tips on purifing iradiated water. its going to come to that eventualy
4. would it be best to bury a shelter deep underground (if so how deep) or to simply put it just under the surface and radiation shield it?
5. how deep into the ground would an emp charge penertrate? could i shield against it just be sheltering deep?
6. What is the safe radiation level for long term exposure? at what rad level can u leave your shelter and live the rest of your life..safely
and anything else u think would be useful


thanks for the advice


1) LETHAL at the area of the strike and downwind for 40 to 120 miles.

2) It varies. Iodine 131 is a major constituent of fallout and have a half life of just 8 days. Strontium 90 is much longer lived and harder to get rid of.

3) Any decent filter would work on getting rid of contamination in water. After the initial explosion, all the residual radiation is from particulate matter anyway and anything that filtered this out would work.

4) IMO it would be best to bury it deeper as opposed to heavily shielding it. It is much cheaper and has a greater chance of working with no problems.

5) In optimal conditions I think an EMP burst could go MILES into the ground. Now if you had everything properly grounded with no connections to outside power, and all the other loose ends covered, I think you'd be fine on top of the ground.

6) This is a very complicated subject.... An adult who was at least 100 miles from the blast, could probably go outside safely after 2 or 3 weeks, depending on wind patterns and the type of nuke used. Children are more susceptible to radiation and would probably require 80 days in a shelter before leaving for maximum safety. After 80 days, radiation levels will fall much more slowly and if there is a measurable amount of radiation in your area, you should endeavor to get the hell out of there asap.

Get a CD meter and learn to use it. If you get even a small reading on it, I would consider moving away from wherever you are. In a full scale war, about 60% of the US would have no appreciable radiation levels after 80 days. The cities would be lethally radioactive for a year at least and it would be unhealthy to live there for 10 to 30 years after the blast.
 

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Answers to your questions

You can find all the answers to your questions in these two government books...Google them and you'll find them as .pdf files

Effects of Nuclear Weapons (1977)
Radiological Defense Manual (1974)

These are excellent books with lots of credible and detailed information...the Government Printing Office may still have paper copies that you can order, I got mine for free back in the early 1990s...

Hope this helps,

DCH Radiation Safety Officer
 

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im sorry if this has been posted somewere but i cant find it.

does anyone know the answer to any of these?

1. what is the radation level just after a nuclear strike? ets say at point of impact with the average nuke then.
2. what is the half life of the radioactive material used in modern nukes (when used) so i know how long to hunker down.
3. Any tips on purifing iradiated water. its going to come to that eventualy
4. would it be best to bury a shelter deep underground (if so how deep) or to simply put it just under the surface and radiation shield it?
5. how deep into the ground would an emp charge penertrate? could i shield against it just be sheltering deep?
6. What is the safe radiation level for long term exposure? at what rad level can u leave your shelter and live the rest of your life..safely
and anything else u think would be useful


thanks for the advice
The average tactical nuke is considered to be 500kt, so will give information based on that.
1. At the site of impact, it won't matter, everything will be dead and destroyed. However, if you are in a buried and fortified blast bunker, you will probably be underground for at least a month, probably longer. With a 500kt surface/near surface burst, most of the fallout drops in the cone of the mushroom cloud and out from 2-15 miles down wind (depending on wind speed) If it is raining/snowing, the localized radiation will be much worse.
2. Get a Radmeter and Dosimeter. The idea is to know how much radiation dose you are receiving in a given period of time. In order to do this you need a Radmeter. You can also get a KFM kit for $55 that is super accurate for determining your potential dose. However, to answer your question, the half life varies and you can only tell by using some form of meter that can measure the radio activity.
3. Contained water is safe. Water from a lake or stream can be filtered with compacted earth, or by allowing it to sit in a bucket for 8 or more hours so that the fallout sinks to the bottom. Then, you can run the water through a 2 micron filter and a carbon filter and it will be fine to drink. Otherwise, boil the settled water.
4. a shelter that has 3' of compacted earth on all sides will absorb 99.9% of all gamma rays. Alpha rays can be easily stopped with clothing, and Beta rays can only penetrate about 1/8" so can be stopped with much thicker clothing. If you went outside, you would want to wear a mask (like a surgical mask).
5. I couldn't answer this one. I do know that if you have any wires, antennas, or metal plumbing that comes into your buried shelter, an EMP will find its way in through one of these medias.
6. No more than 1 Rad per day long term.

All of this information can be found for free here: http://www.ki4u.com/free_book/s73p904.htm It is 280 pages of great infomation.
 

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In the radiation labs we use sheets of plastic, a couple of inches thick, to shield from neutrons, which might be appropriate for shielding from neutron bombs and other forms of enhanced radiation devices. Plastic won't phase gamma radiation, but is effective for neutrons.

This is fairly obvious when you think about it: Plastic is a "hydrocarbon", and therefore has a significant hydrogen content. What is the nucleus of hydrogen? Well... it is a proton. What is closest in size to a proton of all elementary particles? A neutron. Therefore hydrogen has a high cross section for neutron scattering, which tends to quickly thermalize the neutrons. (energy transfer between like-sized particles in a collision is maximized). So in the labs we use lead and concrete for gamma, and plastic for neutron radiation. Of course water also has an excellent neutron scattering cross section, but it is pretty hard to wheel around a big sheet of "water" compared to a big sheet of plastic in a lab, so we use plastic.

Hiroshima is alive and well... I have been there, and it didn't take 200,000+ years to make it survivable. What happens is that you get a really big boom, a *lot* of neutron activation of the surroundings, but most neutron capture/activation matter is very short lived. The remaining primary fissile material is destroyed in the blast, with only the remnants that didn't go boom being left. This is dispersed over a very wide area and blends into the background. That is why we can have nice vacations in Hiroshima without worry.
 
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Exact numbers are impossible to give

What is the radiation level just after a nuclear strike? Lets say at point of impact with the average nuke then.

Exact numbers are impossible to give and not knowing what you think an "average" nuke is, I couldn't even guess at the numbers. If the bomb was a surface burst, you're talking about being in the molten crater. Radiation would be the least of your worries. However fallout radiation is most intense several miles down wind. Any significant distance upwind of the blast you could probably survive with expedient shelter. If it were an air burst, there'd be intense immediate radiation from the explosion itself with a small amount of residual radiation induced by neutrons from the bomb being absorbed by the ground. In tests in Nevada troops were sent into the GZ of air burst tactical nukes immediately after the explosion to simulate combat in a nuclear environment. Nobody suffered acute radiation sickness although they had an elevated risk of various cancers 20 years later.

what is the half life of the radioactive material used in modern nukes (when used) so i know how long to hunker down.

The material used is Plutonium or Uranium. The half life of uranium-238 is about 4.5 billion years and that of uranium-235 is 700 million years, Plutonium is 29,000 years. Neither of these is what you have to worry about. What is dangerous is the short lived isotopes that are produced by the fission process. In an air burst these all get blown into the stratosphere where they take years to fall out and by then most of the activity is gone. In a ground burst they condense on particles of pulverized/molten ground material scooped out of the crater and fall out within a couple days.

The general rule for fallout is that if the intensity is considered 100% at one hour, then at 7 hours it will be 10% and at 7x7 hours (about 2 days) it will be 1% and at 7x7x7 hours (2 weeks) it will be 0.1%. This is called the rule of sevens. For every sevenfold increase in time the fallout intensity will drop to 1/10 the previous level. Because of the vagaries of the wind, it is impossible to predict fallout intensity for a specific spot in advance. There is no good substitute for a good, calibrated radiation meter. As a general rule, the CD literature recommends 2 weeks if you aren't sure of the radiation intensity.

Personally I'd spend as much time as practical in a shielded situation (like sleeping in the shelter, not going outdoors unless necessary and possibly evacuating to an uncontaminated area if possible) for many years after the war just to keep the long term risks as low as I could.

Any tips on purifing iradiated water. its going to come to that eventualy

Filter it like any other impure source. Water itself doesn't become radioactive, however the particles in it may be radioactive.

would it be best to bury a shelter deep underground (if so how deep) or to simply put it just under the surface and radiation shield it?

2-3 feet of earth shielding or the equivalent weight of other material is enough for almost anywhere. Doesn't matter if its feathers or lead as long as you have sufficient mass. 1.5 foot would do anywhere that wasn't in fairly intense fallout contamination, like downwind of a deeply buried hard target (missile silos, NORAD HQ, etc.). A basement shelter is a better idea unless you're in an area potentially affected by blast or fire. Lots of plans for those around and they require a lot less shielding mass for the same protection. Above ground will do just as well if you have a shallow water table. FEMA has plans for above ground shelters that can be be retrofitted into a house that will double as a tornado shelter sufficient to withstand an F-5.

how deep into the ground would an emp charge penertrate? could i shield against it just be sheltering deep?

EMP has been shown to couple into underground power and communication cables, so going underground isn't enough by itself. What is important is NOT having external lines plugged into your equipment at the time the EMP occurs. EMP is coupled into sensitive devices thru phone lines, power lines, external antennas, ethernet cables and such. Shielding an operating computer or radio from EMP is a fairly technical proposition. Having a spare (or spares) on hand in a foil wrapped box on the shelf (Google "Faraday cage") is pretty simple.

What is the safe radiation level for long term exposure? at what rad level can u leave your shelter and live the rest of your life safely and anything else u think would be useful.

The body can handle about a rad a day almost indefinitely and about 100 rads over a couple days without obvious problems. The longer you spread it out the more chance your body has to repair the damage. This doesn't mean it is "safe". You still run the risk of cancer years to decades down the line and a slightly elevated chance of having birth defects in your children.

Over 200 rads in two days and you begin to show signs of acute radiation sickness. Approaching 400 rads death is a distinct possibility and illness a certainty. The average lethal dose is estimated at about 450 rads delivered instantly and without medical care. This was determined by studying survivors of Hiroshima and Nagasaki who were close enough to the blast (within a mile or less) to have been affected by the initial radiation but not killed by blast or thermal effects. For those who survived 400+ rad exposures the road to recovery was long and often never fully complete. With full medical care the 50% lethal dose climbs to about 600 and with heroic efforts (bone marrow transplants, living in a bubble, etc) the medical community thinks they can push it to 1000. What kills in in potentially survivable levels of radiation is the destruction of the immune system and the digestive tract. At 1000 rads brain tissue starts to go.
 
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