Talk:Thorium
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Article changed over to new Wikipedia:WikiProject Elements format by Mkweise and Dwmyers 14:41 Mar 3, 2003 (UTC). Elementbox converted 10:37, 17 July 2005 by Femto (previous revision was that of 23:52, 10 July 2005).
[edit] Information Sources
Some of the text in this entry was rewritten from Los Alamos National Laboratory - Thorium. Additional text was taken directly from USGS Thorium Statistics and Information, from the Elements database 20001107 (via dict.org), Webster's Revised Unabridged Dictionary (1913) (via dict.org) and WordNet (r) 1.7 (via dict.org). Data for the table was obtained from the sources listed on the subject page and Wikipedia:WikiProject Elements but was reformatted and converted into SI units.
[edit] Error
This Wikipedia page repeats a very common error about natural thorium, i.e. that it consists of only one isotope Th-232. This isn't true, though many sources say this. Natural thorium always contains significant amounts of Th-228 (in a radiological sense), its indirect decay product, in the same way that natural uranium always contains U-234, the indirect decay product of U-238. —Preceding unsigned comment added by Careysub (talk • contribs) 21:36, 17 October 2007 (UTC)
[edit] Removed text
I removed this section: "Thorium metal has the treacherous property that although it can be safely handled (even with bare hands!) when newly purified, after just a few weeks it becomes sufficiently contaminated with decay products that this would be extremely hazardous. Even highly skilled radiation workers accustomed to handling other nuclear fuels such as uranium and plutonium have been caught by this."
I don't see how this can be true. The half-life of thorium is 14 billion years and the half-life of of its first daughter is 5.8 years. According to the EPA it takes 7 half-lives of the daughter isotope to reach equilibrium, which is 40 years at which point radiation would be only 9 times greater than the original "safe" dose". Or have I miscalculated? It been a while... Rmhermen 20:34 Mar 17, 2003 (UTC)
The claim came from first-hand stories from people who had actually been caught and contaminated, and probably would prefer not to be quoted. I wasn't really sure whether to put it in. But it's accurate and I think it's interesting.
I think the main problem with your calculations is that they assume that the danger is direct radiation. In fact the main danger is surface contamination and subsequent ingestion. Some of the daughters are a lot more mobile than the original thorium.
I haven't done the calculations myself or even looked up the details of the chain. But do your calculations take into account the different energies of the various decays? That's very important too.
With a chain like this, where the first decay is by far the slowest, as equilibrium is approached the number of decays per second of each stage becomes roughly equal. (Yes, I know we're still a long way from equilibrium, stay with me!) However, the radiation from some stages is a lot more dangerous than from others. (In fact the shorter half-lives tend to indicate more energetic decay and more dangerous radiation. Not always, for example Radium 222 in the Uranium series is quite nasty.) This effect will be important long before equilibrium is reached.
Comments? Would you like to have a go at rephrasing it, or do you still think it doesn't belong in? Andrewa 00:45 Mar 18, 2003 (UTC)
- In that there's been no reply to this, I'm going to have a go at rephrasing and reinserting this text. It's accurate, and highlights very well the surprising complexities of radioactive contamination. Andrewa 18:15, 4 February 2006 (UTC)
Removed: "The thorium decay chain ends with an isotope of lead (208Pb), but passes through an isotope of radon (220Rn) (also called "thoron")[1]. Radon gas is a radiation hazard. Good ventilation of areas where thorium is stored or handled is therefore essential."
In equilibrium there is only about 1 micro gram of radon present for every 200 tons of thorium. At a half life of only 55 seconds it doesn't even have time time to seep out of the thorium matrix and reach anyones lung. This is simply not a hazard.
[edit] Heinlein universe
Robert A. Heinlein envisioned thorium as being the principal fuel of the advanced space-travelling civilizations described in his novels Have Space Suit—Will Travel and Citizen of the Galaxy. Does that have a place in this article? Ellsworth 16:32, 10 May 2004 (UTC)
Ra = radium, not radon. Chris
[edit] Thorium as nuclear fuel
Much development work is still required before the thorium fuel cycle can be commercialised, and the effort required seems unlikely while (or where) abundant uranium is available.
It may seem unlikely, but it's exactly what India is doing! Is this deliberately phrased to exclude India, and so make it sound as though it's not happening, while not actually denying that in fact it is? Andrewa 18:15, 4 February 2006 (UTC)
Thorium may be used in subcritical reactors instead of uranium as fuel. This produces less waste and cannot melt down.
This was wrong, Thorium can be used in critical reactors, too, and produces only less amounts of transuranic wastes. Most importantly, subcritical reactors aren't meltdown-proof, they could melt from after heat just like critical reactors could. This is probably not the right place to discuss all aspects of Thorium as nuclear fuel. 88.74.137.143 14:24, 21 January 2007 (UTC)
I have added a couple lines here, they are difficult to merge into the current text which I believe is in error. I did not want to mention the company that is commercializing the seed and blanket technology by name (Thorium Power Ltd.) but the process by which the Indians are proceeding is the breed - extract - feed cycle, which is still years away from being viable and what is referred to in the part just past my insertion as being untenable with high fuel fabrication costs. The cost estimates for Thorium power designs is 15% less than conventional 4% enriched uranium.
I believe that the first line in thread is wrong. Much work has been completed and Thorium utilization may be just around the corner.
Adapter (talk) 23:13, 9 March 2008 (UTC)
[edit] World of Warcraft
Thorium is also a fictional metal in the Warcraft universe, and can be mined in World of Warcraft. Why why why does this exist in this topic... :
- >>Other Usages
- Thorium is a strong metal in the Warcraft game universe, and more specifically World of Warcraft. In World of Warcraft, this is one of the highest-level mineable metals, and Alchemists can transmute it to Arcanite.
Thorium from WoW bears little in common with the properties of the real-world element Thorium. 83.71.144.13 (talk • contribs) 09:49, 21 July 2005 (UTC)~
- References to this get removed, added, removed, added again... Everybody should agree that the WoW metal is very different from the real one, and as such, not a fictional use of this element. (I think even Heinlein's 'real' fictional use would be pushing it, notability-wise.) The borrowed name might deserve a disambiguation link to a separate Thorium (Warcraft) article though, if the material is notable enough in the Warcraft universe. Femto 14:57, 2 April 2006 (UTC)
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- Added "See thorium's entries at fictional applications of real materials" which seems to be the most elegant solution. Femto 14:36, 16 April 2006 (UTC)
- I think anything to get the general public interested in science is worth it. —The preceding unsigned comment was added by 71.222.149.170 (talk • contribs) .
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- This page needs to show some boobies, that'll catch their interest. Unfortunately, it would be just as unrelated to the topic as fictional alchemists and space travellers. Femto 13:14, 30 September 2006 (UTC)
[edit] In popular culture
I removed this statement
- In 1999, a group of University of Chicago students taking part in the annual scavenger hunt built a small, working nuclear reactor.
which someone had put a {fact} tag on. (The sentence was originally added at 13:33, 12 May 2006 by User:Danpat.)
As it happens, the University of Chicago Scavenger Hunt article contains a link to http://www-news.uchicago.edu/citations/99/990519.scavhunt.nyt.html which does corroborate the scavenger hunt story. However, I can't see any evidence that Thorium was specifically involved. (That article mentions only Plutonium.) —Steve Summit (talk) 04:11, 11 October 2006 (UTC)
It is difficult to determine whether David Hahn is a fictional or real person. I thought "in popular culture" implied he was from a TV movie etc. --Dunkankan 01:32, 21 October 2006 (UTC)
[edit] Norway lucky as always
Like the oil, Norway still has the luck on sitting some huge quantities of valuables. I just think it is fun and strange at the same time.
- Nor does rime with Thor. -lysdexia 03:05, 2 February 2007 (UTC)
[edit] New Development
I don't know if any one wants to add something on this but it just recently happened. Thorium uses to date stars in far-away galaxies using the same method as with carbon dating. I haven't got a source, though. It was on Google News.
[edit] Translation into Chinese Wikipedia
The capitles Distribution and Thorium as a nuclear fuel of the version 15:31, 26 October 2007 TheoClarke are translated into Chinese Wikipedia.--Philopp 10:29, 3 November 2007 (UTC)
[edit] radioactivity versus half-life?
There are substantial deposits in several countries. 232Th decays very slowly (its half-life is about three times the age of the earth) but other thorium isotopes occur in the thorium and uranium decay chains. Most of these are short-lived and hence much more radioactive than 232Th, though on a mass basis they are negligible. India is believed to have 25% of the world's Thorium reserves. [5]
has a phrase in it which didn't look right to me.... "Most of these are short-lived and hence much more radioactive ..."
is an element more radioactive if it has a short half-life, or does it have a short half-life because it's more radioactive??
i'd suggest that the phrase be replaced by
"Most of these, much more radioactive than 232Th, are short-lived, though on a mass basis they are negligible."
does this make grammatical and scientific sense at the same time?
thanks for considering... Plusaf (talk) 01:22, 28 November 2007 (UTC)plusaf
[edit] If Thorium is a safer way to produce Nuclear Energy then why not impose it on Iran?
Seeming that Thorium is no threat to creating a bomb. It seems like a wise investment for the world. More abundant and easier to mine with a less hazardous by product. —Preceding unsigned comment added by Mahovictor (talk • contribs) 00:10, 29 December 2007 (UTC)
[edit] Thorium safety -- and mantle lamps?
Okay, so thorium decays into other radioactive elements and "is safe if not handled, but aerosolized thorium is hazardous".
In a mantle lamp, the thorium is intensely heated and there is a strong air updraft through the mantle mesh. It would seem this is a perfect opportunity for the thorium to become aerosolized. So are mantle lamps really safe in an enclosed space such as a house, or not?
