I agree with the idea that what's probably happening is that the filter is removing some radioactive dust. It cannot remove radiation per se, but if the dust is the big problem then it might help a lot.

If the only problem is dust contamination, you don't necessarily need a professional filter (though that helps). You could strain water thru several layers of very fine cloth, or better still through some of those large filter papers that chemists use when they do experiments. You just need to filter the water to some sub-micron level. However, if the process takes a long time that may be frustrating.

On the other hand, if the water contains dissolved materials that are radioactive - then you've got a problem. A filter won't get out dissolved materials - you would need to evaporate the water to clean it in that case.

Do you own a Geiger counter that could even measure the radioactivity from water? I don't have one, and I wonder how many people actually do.

Pete2

I just took a look at the Sawyer "Complete Water Purifier System" and its published specs do indicate it would remove particulate 10 times smaller than any of Katadyns. Plus its small and you don't need to fret over having extra filters, ever. You just backwash it by reversing the filter flow with clean water. In other words it would seem that you could keep it from getting hot by back washing it frequently.

In regard to scenario #2 (i.e. getting water out of an open pond or stream while traveling), this Sawyer might be about the best you can practically do if on the move.

As to purifying irradiated water, one would need to find a water distillery that you can "reliably" depend on that is portable and operates w/o electricity and at low pressure (below 140 psi). Wouldn't the metal in any such water distillery itself become contaminated from irradiated water? And what do you do then? Or would the contamination be something that could be cleaned, such as NORM contaminated scales on steel pipes can be cleaned? And in any case, carrying enough fuel to keep the water distillery running, even for a week, would be a challenge.

According to the WSJ, irradiated water showed up in the Tokyo water supply due to the fuel rods. I suppose we'll see a lot of thyroid cancer there in the years to come. Say it ain't so.



In dealing with purifying irradiated water, I'd think it would be helpful to have a Geiger counter that can measure "the radioactivity from water"? Any suggestions?

I want to thank the board members for the insight they have shared and especially in putting this topic/issue in perspective.

As a side note, many years ago I met a man who probably could have answered every question. He was a Nobel Prize winning nuclear physicist by the name of Eugene Wigner. He had come to LSU to teach. It was Wigner who wrote the letter to Roosevelt (that was signed by Einstein) that started the Manhattan project. Because it was known that the Germans had the White House under constant surveillance, Wigner and Einstein decided that they would have the letter urging the development of the atomic bomb delivered by Wigner’s wife (who they didn’t think the spies would recognize). They didn’t. Wigner taught at LSU for two years before returning to Princeton.

GradyT34...I have a Sawyer .1 micron 5 gal bucket system for hurricane season, and am impressed with the product, though have just used it for testing... the Adventure Savety Products people are recommended outlet by Sawyer...

Any chem majors here? Are there chemicals that can be used to treat the water which would cause the radioactive ions/particles to precipitate out of solution?

I'm not a chem major but I am trained in radiological controls.

Part of the problem with radioactivity spills from bombs or reactor breaches is that there are a wide range of radioactive fission products released. Some of which decay on their own in a short time because they have short half-lives, some of which are so long-lived that they essentially "never" go away. Some short-lived elements decay to longer-lived radioactive elements too. It's a big messy mix.

This means that a chemistry based approach isn't likely to be complete.
For example, if you treat for iodine to remove it, what about Strontium? What about Co90? Will the chemistry to precipitate Iodine work on Strontium or Cobalt?(or the other dozen possible materials)?

I'm sure a chemist could concoct something to remove all the radioactive elements if you told him beforehand what they are or will be. But without this knowlege, a chemistry-based approach seems to me to be unlikely to work.

BTW- I DO have a couple of radiacs. One is a chargeable (very short term use) personal dosimeter exactly like what I used in the Navy when entering a known radioactive area (such as the shutdown reactor compartment). The other is a Civil Defense area radioactivity detector. It self-tests ok but without a radioactive test source to try it on I don't know if it works. What we had aboard ship were several additional calibrated, expensive, instruments. We also had several specially trained people who had a lot more training in the art.
Doing this at home on your own is not terribly practical.

So I personally try my best to not be present when accidents or detonations happen :-)

As I understand it, the radioactivity of a particle is independent of the chemical property: that is, the same chemical reactions work in the same way on radioactive particles as they do on their non-radioactive counterparts.

Thus, to precipitate particles out of water, you need a chemical reaction that is probably unique to that chemical element or molecule. Since a large variety of elemental particles/molecules can become radioactive, I am going to guess that it is unlikely that their is a single, or even a small number of chemical reactions that would precipitate out every possible radioactive element.

This exhausts my physics and chemistry.

Blast---can you give us some input from someone who actually knows what he is talking about?

This is just from a translated webpage, but apparently the Japanese Society of Radiation Safety Management did some experiments after the earthquake with readily available household products to see if they could filter out the radioactive particles from water. They used the common pitcher-style water filters many of us have sitting on our kitchen counters, and found that they removed a very high percentage of the particles.

I read this here.

Certain radioactive isotopes will actually dissolve in the water (I believe radioactive iodine falls in this category) and which requires other methods to remove from water, such as ion exchange.