Radiation risk from school experiments?

[Barto]

We recently did experiments in school using sources of Radium-226, Americium-241 and Strontium-90. They all had a strength of around 185 kBq. In some of the containers there was only a very thin piece of foil keeping the material inside, or so I was told. Since the experiments I've kind of been freaking out about a possible leak. If anything had leaked, would it have been possible for all the material to come out in a single grain? Because if you accidentaly ingested that grain somehow, I think it would give you a pretty large radiation dose. And if I was working at the table where a leak occurred, it might have gotten onto my clothes and I could've brought it into my home perhaps. I know it probably sounds stupid, especially since there is no indication that anything did leak (although they haven't tested them again yet), but I can't help obsessing over it. I'm not worrying about radiation poisoning or anything like that, but it's the possible long term effects like cancer that worry me.

 

[mgb_phys]

The source is generally plated onto the foil - it can't escape.

They are mostly alpha emmitters they radiation doesn't go through your skin.
To do any harm you would have to grind up the foil into particles that you can breathe in, and probably convert the metal into a form that could be chemically absorbed by your body.

 

[theCandyman]

Haha, I remember my dosage meter from my uni's lab sent me me dose results for the year. Even though I had left it right by a small source for a while, my dose was still only 0.1 rem.

 

[Astronuc]

We recently did experiments in school using sources of Radium-226, Americium-241 and Strontium-90. They all had a strength of around 185 kBq. In some of the containers there was only a very thin piece of foil keeping the material inside, or so I was told. Since the experiments I've kind of been freaking out about a possible leak. If anything had leaked, would it have been possible for all the material to come out in a single grain? Because if you accidentaly ingested that grain somehow, I think it would give you a pretty large radiation dose. And if I was working at the table where a leak occurred, it might have gotten onto my clothes and I could've brought it into my home perhaps. I know it probably sounds stupid, especially since there is no indication that anything did leak (although they haven't tested them again yet), but I can't help obsessing over it. I'm not worrying about radiation poisoning or anything like that, but it's the possible long term effects like cancer that worry me.

Did one actually handle the sources?

Were the students scanned after the experiments? We had to put our hands near a detector whenever we left the lab, and we had to put up with the HP monitor (and fellow students) who did various scans of us and the lab area.

The sources are designed to be safely used in the lab. I worked around a number of different sources, including fissioned U-235 and Pu-Be sources - and I'm not worried about cancer.

 

[HotCells]

A 185kBq source of pure Am-241 has a mass of only around 1.5 µg. Because of the relatively short half-life of Am-241 (430 y) and the high inhalation toxicity of this material, inhalation of this amount of material would result in a very high radiation dose. However, as stated in an earlier post, this material is plated into the foil. In general, alpha emitters are a serious helath hazard if inhaled.

 

[Shukie]

What do you mean by 'plated into the foil'? Some of these sources are 30-40 years old and they look like this:

http://img198.imageshack.us/img198/8221/naamloosys.jpg

In the ones we used, you could see a piece of very very thin tin foil behind the mesh. The material doesn't just lie on top of the foil but is actually 'pasted' on top of the foil? Even the ones that are ~40 years old were made that way? My teacher didn't really seem to know.

 

[Shukie]

Anyone know the answer? I'm still worrying over the possibility that the material is simply just lying on top of the foil and would fall out in case the foil is perforated.

 

[minerva]

These are sealed sources.

(They're not sealed within thick, robust capsules like gamma-emitting sealed sources, because they're alpha emitters, and you can't encapsulate them too much without stopping the radiation from getting out.) (This applies to the alpha-emitting Am-241 and the Ra-226, not the Sr-90.)

The radionuclide is either electrodeposited onto the surface of the foil (hence it's bound into it pretty well) or it's trapped within a 'sandwich' of laminated layers of thin metal foil. One should generally be careful not to scratch or physically damage the active radioactive surface of these alpha sources.

Now, this might vary a little from country to country with different health physics regulations, but your school's radiation safety officer is probably required to perform periodical leak tests on sealed sources.

This basically means thoroughly wiping over the surface of the sealed source with an alcohol swab or similar and testing the swab for radioactivity, to make sure that none of the radionuclide is coming out of the sealed source in an unsealed way.

Basically, in general, if you're a student at school doing experiments, and you are not trained in health physics and radiation safety, it is the responsibility of those staff who design the experiments and supervise and TA you to ensure that you are not harmed and your radiation doses from performing these experiments as directed are insignificant.

 

[aznsaiyan1029]

alpha particle usually can be stopped with a thin layer of paper from what i learn in class. Your teacher should have explained the possible radiation safety before you proceed right?