Capturing radioactive particles in air

winnie_t

Hi!

I know that there are several way to capture radioactive particles in water, but does anyone know how to capture the particles in air? I thought above using moisture to trap the particle, but what if temperature is very low hence hard to introduce moisture? Is there any other ways to trap the radioactive particles in air?

nikkkom

HEPA filters.
Bubble air through some water.

winnie_t

I actually meant air as in the atmosphere, open air.

terryphi

Oh man, I actually wrote a paper on this!

https://www.dropbox.com/s/j2s6y3s8p8...REVISIONS.docx

Drakkith

What about those two examples says that it isn't using open air?

winnie_t

[QUOTE=terryphi;4252169]Oh man, I actually wrote a paper on this!

terryphi, I have a read through your paper, but I still don't understand (sorry I don't know much science at all, so if you don't mind explaining in laymen's term...)

what was the reason for radioactive balloon? and so how is it possible to capture the radioactive particles in the air?

winnie_t

did you mean "HEPA filters and Bubble air through some water" ?

I am trying to work out how to prevent the radioactive particle from traveling through the air so I'm really looking for some method that can attract the radioactive particles and capture them in air, like how Zeolite would capture the radioactive particles in water.

Drakkith

Ah I see. You want to disperse something over a wide area that will trap the radioactive particles.

terryphi

The progeny of alpha emitters are ionized. If you have a statically charged surface, they will stick to it.

winnie_t

yes, exactly. it would normally be possible to capture it using moisture in the air? but I wonder what if the temperature is really low can moisture can't be form? there must be other way to capture the radioactive particles...

so it would be exactly opposite for the beta emitters?

Drakkith

Winnie I have no doubt that moisture in the air will capture at least some radioactive particles. Rainfall and other precipitation does have the effect of clearing the air. HOWEVER, remember that some radioactive particles are actually gasses and will not be cleared out like others will be.

winnie_t

Thanks Drakkith, thats a very good point. I don't think I have a clear picture of how radioactive gasses behave, do you have any suggestion where I can find out more?

Drakkith

I can't say I do. I am not an expert in nuclear engineering. However, I would recommend that you first find out what radioactive particles you are wanting to trap. Are you doing this as an amateur project, or do you have working knowledge of radioactivity?

winnie_t

no, I'm actually an architecture student, I'm just researching for my building design, I'm trying to capture Caesium-137 and Strontium-90.

Astronuc

those isotopes would be deposited on dust particulates, to one simply needs filters in the air intake system.

Sr and Cs isotopes are either direct fission products are come from decay of precursors, which are fission products.

Se > Br > Kr > Rb > Sr, and Sr decays to > Y

Te > I > Xe > Cs, and Cs decays to Ba > La

One would probably want a coarse filter followed by a bank of HEPA filters, with minimal pressure drop to minimize energy required for airflow.

Halides, Br and I are absorbed on activated charcoal filters, which is best done at the source.

winnie_t

Thanks Astronuc.

Sorry for my lack of knowledge here, so you mean to try to absorb Br and I before they decay into Sr and Cs? What if it is already at the stage of Cs and Sr? Would I be able to some how capture them as they release into the air? is there other option besides filtering the air?

Astronuc

I was providing the decay chains. The place to capture Br and I is at the nuclear plant, which is what plant systems are designed to do. Radionuclides of Br and I decay to corresponding Kr and Xe isotopes, and being noble gases, they cannot chemically react, so they are readily transported in the atmosphere. Radionuclides of Kr and Xe decay to Rb and Cs, and these will deposit on surfaces and on dust, where they decay to Sr and Ba respectively. Rb and Cs are like Na and K, so they are readily soluble in water, and will usually be found in the ground or water. For a building, air filtration through a coarse filter followed by a fine filter works best.