View Full Version : Naturally occurring radioactive areas in the earths crust


Marsoups
10-16-06, 01:30 AM
Hi all,

I have a question. Does naturally occurring radiation (similar to nuclear waste radiation) occur naturally anywhere in the earth's crust ??

I've been trying to research this on the www but there's not much information pertaining to this, so I thought I'd put this question out there.

It's just that, as Australia is looking at the option of nuclear power, the idea of waste disposal could more easily be understood if people understand that the crust does _already_ contain radioactivity, it's just that we don't really want to touch any of it.


CHeers..

Laika
10-16-06, 01:58 AM
Hi Marsoups.

The short answer is yes. Uranium, potassium and thorium are the main naturally occurring radioactive elements on the Earth, and they occur in sufficient quantities to make granite and its weathered clay products appreciably more radioactive than, say, a clean quartz sandstone. Even higher concentrations of uranium occur too of course - the ores from which uranium fuel is extacted. But I'm fairly sure that even high grade ore does not constitute the same hazard as high level nuclear waste.

(Mind you, having said that, natural geologic and hydrologic processes have conspired at least a few times to form a natural nuclear reactor, though it was a couple of Gya. Google 'Oklo natural reactor' if you're interested.)

Marsoups
10-16-06, 04:20 AM
Thanks for your response, that is interesting...
Australia is currently looking at nuclear power so I asked this question as I'm having a debate on another forum...

Nuclear waste is not a thing that many of us want, but for me , in the nuclear debate, I feel that there are plenty places in the earths' crust that are probably hazardous to humans, which seem to be pretty secure. We don't want to go *too* nuclear, where nuclear power gets out of control, but I feel that it is a good step is reducing greenhouse gas emissions.


:)

guthrie
10-16-06, 04:27 PM
google "natural nuclear reactor". There was a palce in Africa where it appears that Uranium ores were conentrated by water and stuff, such that some limited fission took place thousands of years ago.
Or else a UFO crash landed... ;)
Oklo I think is the name.
You are also aware that granite gives off Radon gas, which is radioactive. Living in Cornwall and Aberdeen is not so good for your health, if you live in a house made form granite.

I see Laika has beaten me to it with regards to Oklo. Ahh well.

Walter L. Wagner
10-16-06, 05:11 PM
Check out www.uraniumtiles.org

You likely have lots of Uranium ore lying around on or near the surface of Australia, just waiting to be mined. You almost certainly have Uranium that's been glazed onto the tilework of the older houses, swimming pools, bathrooms, and other places where you folks used tiles in Australia, though not enough to do more than fuel a few reactors, if collected up and scraped off.

Walter L. Wagner
10-16-06, 05:13 PM
Also, Thorium oxide is quite plentiful (and a good nuclear reactor fuel, and can be made into fission bombs via manufacturing), and usually occurs in sands, such as in India, or Long Island, New York, or Brazil, etc. It's about twice as plentiful as Uranium oxide.

imaplanck.
10-17-06, 12:33 AM
Hi all,

I have a question. Does naturally occurring radiation (similar to nuclear waste radiation) occur naturally anywhere in the earth's crust ??

I've been trying to research this on the www but there's not much information pertaining to this, so I thought I'd put this question out there.

It's just that, as Australia is looking at the option of nuclear power, the idea of waste disposal could more easily be understood if people understand that the crust does _already_ contain radioactivity, it's just that we don't really want to touch any of it.


CHeers..

That is a good question seeing as some inhabited areas of geologiacally occurring radioactivity emit more sieverts than well managed nuclear waste sites, with no noticable increase in cancers. Another thing that the anti-nuclear brigade dont seem to realize.

Marsoups
10-18-06, 03:20 AM
Thanks for your answers chaps, that stuff about the tiles is pretty interesting...

imaplanck, I agree with your views there... Obviously nuclear work requires the stiffest control structures, warning labels cast over all its items etc. etc., we are an intelligent race now, we should now how to deal with it in bits and drabs....

_obviously_ nuclear power isn't the only alternative, we should be investing more into solar power and renewable sources , a bit of everything won't hurt, as long as it is managed well.

The issue of course, is third world countries wanting nuclear where their controls are slightly less stable than in first world countries.. That is a concern I think.

Ophiolite
10-18-06, 04:18 AM
The issue of course, is third world countries wanting nuclear where their controls are slightly less stable than in first world countries.. That is a concern I think.This link is interesting. It provides information on all the nuclear facilities around the world, down to details such as what the control rods are made of.
http://www.insc.anl.gov/pwrmaps/map/world_map.php

Roman
10-19-06, 09:40 PM
Radon gas seeps up into people's houses worldwide from radium that decays in the earth's crust, particularly regions with granitic soils.

Here's the wiki entry:
http://en.wikipedia.org/wiki/Radon

MetaKron
10-19-06, 10:30 PM
Walter, thorium is not usable in bombs unless it is made into a fissile isotope of uranium or thorium. It is good for use in a kind of breeder reactor that is safer than one for uranium, and thorium is more abundant than uranium.

Walter L. Wagner
10-19-06, 10:49 PM
Metakron:

There is no fissile isotope of Thorium that can be used for a bomb.

The use of Thorium to make a bomb converts Th-232 to Th-233 via neutron irradiation in a reactor. It beta-decays twice and forms U-233, which is readily fissionable via slow neutrons, as well as fast. In fact, U-233 is better for bomb making than Pu-239, which in turn is better than U-235. However, no one does it that way (U-233) as of yet. Thorium has been used in at least one German reactor as an adjunct to the U-235(/U-238) fuel, where it is essentially bred into in-situ U-233.