How to protect yourself from radiation?

[nucleargirl]

I was wondering... how do nuclear physicists protect themselves when they are doing experiments with radioactive material?? do they wear some suit of some kind? or do they work behind some kind of barrier? or do they not need any protection at all? I can't find this anywhere on google... someone enlighten me please!

 

[fatra2]

Hi there,

A short answer to your question is in two parts: distance and shielding.

I am taking a case where exposition is essentially due to man-made sources. There are only two ways to reduce the amount of exposition: 1. you can increase the distance between you and the source, 2 you can add some slab of shielding to absorb some radiation as you work.

Now for the gears that you see in the Simpsons. They are put on only for the contamination. Meaning that you don't want to work with some radioactive source, and carry most of it home at night. Therefore, if the source is very intense, and the material can be spread around, you are better of to wear protective clothing that you leave at the lab/power plant. Otherwise, these protective gears do not protect you from the radiation (ah, ok some alpha/beta radiation will be absorb).

Lastly, people exposed to radiation in their work life, well they are just exposed. We are not allergic to radiation. It is simply in the amount that we have to be careful. Therefore, these people are followed very closely by a medical staff for the effect of radiation. There is also (in my knowledge in all the countries in this world) a limit to the absorbed dose that workers can take on a yearly basis. Above that limit, they are freed from their work and considered medically inapt to work.

Hope this helps. Cheers

 

[HallsofIvy]

"protective gear", not "protective gears". (That made me think about some kind of rotating gears!)

Also, some protective gear has a thin lining of lead which helps to protect works from radiation. A thicker layer would protect more but would also be very heavy!

And, since fatra2 mentioned "The Simpson's", there is a scene in the opening of each program in which Homer is using gloves set in holes through a wall to work with radioactive material. (Since his job is "safety manager" I have no idea why he would be doing that, but...) That is also protection but not so much agains radiation. Even impregnated with lead (which is done) glass does not give all that much protection against radiation. It is mainly protection against poisoning. Radioactive minerals tend to be "heavy" metals and heavy metals, even without radiation, are poisonous.

 

[nucleargirl]

thanks guys! that's very interesting. So it seems that you are not really protected at all then - distance from source - surely you have to work using your hands? so the distance between you and the material can't be over a meter...
and slab of shielding - how can you work when there is a block in between you and the material?
and it seems like the suits don't really do that much to protect you...
it all sounds like a very dangerous job!
so how long do most nuclear scientists work for in a year? a few months? weeks? what do they do the rest of the time?
and is there a higher prevelance of cancer among nuclear personel? and genetic defects among their children?

 

[HallsofIvy]

I'm not sure what kind of "slab" you are thinking of. A fairly thin layer of lead will give protection agains light radiation- and most workers never get near really strong radiation.

Where it is necessary to work with strong radiation, workers use "Waldos"- manipulating controls which then move or work with the material while the worker observes it through a closed circuit television. Rather than "not over a meter" the distance between the worker and the radioactive material could be many miles- although 10 feet or so is more common.

The term "Waldo", by the way, is from an Isaac Asimov science fiction story.

 

[Naty1]

"it all sounds like a very dangerous job!"

Not really...but things like Chernobyl and Three Mile Island do happen...in the former massive and very dangerous radioactivity was released, some radioactive gas in the latter case...

except in particular areas of nuclear power plants, for example, there is little radiation. Workers wear "badges" that record radiation exposure and are closely monitored. When I studied around a sub critical nuclear reactor, for example, we were instructed to remove our badges when going outside...because the "radiation" even around the underwater reactor was so low that exposure to the outside sun would have recorded higher levels than were present inside the reactor building.

When working in high radiation level areas, workers are strictly limited in the time they are exposed...so there is potential danger, just like driving where mistakes have consequences.

Others work in nuclear medicine and while technicians may wear protective gloves (and badges) for handling patient doeses, the radioactive isotopes are relatively weak. I had thyroid nodules treated some years ago...I forget which iodine isotope...and within a week or two the active period of the isotope had passed (very short half life).


Here's some information on that sort of isotope and treatment from Wikipedia...
http://en.wikipedia.org/wiki/Iodine-131..

As you may know, the type of radiaton is also sigificant..alpha, beta or gamma ray exposure are not all equally serious...

I'm not sure exactly how much "hands" on work nuclear physicsts actually do with radioative material...

 

[QuantumPion]

Hi there,

A short answer to your question is in two parts: distance and shielding.

Actually it's 3 parts, you forgot time (as in minimize the time you are exposed to the source).

 

[nucleargirl]

ah I see! so the most dangerous work are carried out in hot cells! using remotely-controlled arms! that would make it a lot safer I guess. Very interesting, I guess a LOT of design must go into building nuclear facilities since the radioactive stuff can't really be transported too far... or can it? how?
nuclear stuff are so interesting - they're not quite like any other material - they are almost alive in a way! giving off emissions, changing in property over time...
and they are so exciting cos they are so dangerous!

 

[schip666!]

There are fairly strict regulations covering the transport of radio-active materials. They specify the amount of radiation that can be measured on the outside of the container, and those amounts are very low. A small lump of fissionable material may be buried in a 55 gallon container of lead, and only a few of those containers can be on the same vehicle. Those vehicles must have police escorts as well. If you have the stomach for federal regs you can probably find all the details here:
http://www.phmsa.dot.gov/hazmat/regs

All nuclear workers wear dosimeters which record the amount of radiation exposure. Some are simple pieces of film that get developed and the foggyness measured. Fancier ones can be read immediately, for use in high radiation areas where the allowed exposure is measured in seconds or minutes.

One of my Hazmat instructors was a fire-fighter in Los Alamos, NM. They all have to wear dosimeters in case they respond to incidents at the lab. He, and his protective equipment, took an airplane to a training on the east coast and he forgot about the dosimeter. When he got back it showed a radiation over-exposure and he had to fill out reams of forms to explain that it was just from being at 30000feet for a few hours. So that's how sensitive they are...

 

[splitringtail]

Protection is usually described in terms of time, distance, and shielding.

It is a little easier to understand when you divide radiation into two areas charged (alpha particles, betas, protons, ions,...) and uncharged (photons and neutrons).

Since most charged particles of most energies are easily stop by a few sheets of paper or your clothing and dead layers of skin, the real harm they present to people is contamination particularly inside the body. That is what suits are for, however, quite a bit of lab work is done with simply a lab coat, gloves, goggles, and disposable covers on your shoes. You cannot move away from a radionuclide collected in your lungs and can only decay away. For sufficent radioactivity and to minimize dose as much as possible (in the radiation and nuclear business this is called ALARA [As Low As Reasonably Achievable]), radioactive materials are handle in glove boxes or behind plastic barriers.

Lead is mostly for stopping gamma rays. For neutrons, hydrogenous materials are used to slow them down and capture them. Uncharged radiation interacts with materials in a exponential manner, thus there is also some radiation no matter how much shielding there is.

For really radioactive materials they are handled in a hot cell where the human controls robotic arms in the cell to do work.

I would have to look it up but according to my Radiation Biology class... the incidents of cancer for radiation workers in the lab similar to workers in non-radioactive labs. Few studies found that incidents of cancer in radiation workers is slightly lower than the general public. The reasoning was that concluded that radiation workers were more educated, so they lived healthier life styles.

 

[splitringtail]

I rather be surrounded by Pu, 5 days a week than hydrofluoric acid.

 

[nucleargirl]

oh my god tell me about it! Labs are the most dangerous places ever! Once I was working with methanol - which I thought was the same as ethanol, and I got some in my eyes! thinking it was fine, I went home, went to sleep and woke up at 4am unable to see anything! had to go to A&E straight away! that freaked me out so much!

 

[Astronuc]

ah I see! so the most dangerous work are carried out in hot cells! using remotely-controlled arms! that would make it a lot safer I guess. Very interesting, I guess a LOT of design must go into building nuclear facilities since the radioactive stuff can't really be transported too far... or can it? how?
nuclear stuff are so interesting - they're not quite like any other material - they are almost alive in a way! giving off emissions, changing in property over time...
and they are so exciting cos they are so dangerous!

Basically for highly radioactive areas (especially were highly penetrating gamma radiation is present), work is performed by remote processing/handling.

Glove boxes could be used for alpha emitters or low energy beta rays, otherwise remote control mechanical or robotic arms are used, or the equipment is design to work without direct human interaction.

For high energy particles, basically the area affected by radiation is supposed to be empty while the accelerator is operating, and places where particle beams interact with targets are also empty (vacated) while the particle beam collides with the target. Then one has to wait while short-lived radionuclides decay if they are produced.

In the commercial nuclear industry, much work is handled by robotics and sometimes folks monitor with remotely controlled submersibles with high resolution video cameras.

 

[Bob S]

Or you could just buy Thyroshield^TM pills from [STRIKE]Nucspills.com[/STRIKE] Nucpills.com to shield your thyroid from radiation (Now including a fruit-flavored syrup for children!).

http://www.nukepills.com/potassium-iodide.htm

Bob S

 

[fatra2]

Hi there,

Basically for highly radioactive areas (especially were highly penetrating gamma radiation is present), work is performed by remote processing/handling.

Whenever possible. When it is impossible for remote processing/handling, then work is limited in time in these areas.

Specially during maintenance procedures, it happens (rarely thankfully) that work has to be done in an area with more 100mSv/h. In a case like that, the worker stays a very short while, and is then medically followed.

cheers