Talk:Yellowcake

Why yellowcake?
Why is it called Yellowcake? Is it yellow? Edward 12:46, 7 Nov 2004 (UTC)


 * It used to be, hence the name, but isn't any more due to changes in the manufacturing process. I've updated the article to reflect this. -- ChrisO 17:09, 7 Nov 2004 (UTC)

But... why the part about cake? Sure it may look like a cake or something, but you don't called radioactive materials "cake"! >_< Jobjörn 23:59, 17 August 2005 (UTC)


 * Well, actually, we do. It's a bit like calling something Green Field when the site is neither green nor a field. Wikipedia doesn't decide this sort of usage, we just report it. Andrewa 17:56, 29 December 2005 (UTC)


 * PS Banana cake is also radioactive, largely owing to the natural Potassium-40 in the bananas. So is every other food, but many of them less so. Banana cake may also be yellow, but is more often brown, like yellowcake. Enjoy! Andrewa 18:05, 29 December 2005 (UTC)


 * A cake of soap? ;) —  Jeremy  Talk  07:57, 14 May 2007 (UTC)


 * In the World Book Encyclopedia edition from the late 1970's, the article on Uranium had a picture of a sheet of what must have been still wet yellowcake. It quite resembled a common yellow sheet cake. I'd presume that at some point, some smartarse working with the stuff quipped that it looked like a yellow cake and the name stuck. Bizzybody (talk) 09:11, 2 September 2011 (UTC)


 * cake can refer to something's consistency, it does not have to be a food. cake of soap is a good example ^^^ Ottawakismet (talk) 16:47, 12 March 2014 (UTC)

Funny edit
I laughed and laughed when I saw this in the history. This edit came from an IP, not an account and someone has already reversed it, but wow, it was soooooo funnny, that I thought I'd put it in the talk page:

Contrary to the perception in certain circles, Yellowcake should not be used in the preparation of confectionary products, and appropriate measures should be taken to avoid mislabelling.

ahahahahhahah avoid mislabelling in case your grocery store accidentally sells you yellowcake!?! Ottawakismet (talk) 16:45, 12 March 2014 (UTC)

Yellowcake is NOT U3O8
Yellowcake is not U3O8. U3O8 is formed by high-firing of the UO2 or UO3 forms, typically in excess of 800 oC for an hour or more. It is a black, particulate powder, similar in consistency of sand, though the particles are more rounded. The term Yellowcake actually refers to the product produced when uranium is precipated using ammonium hydroxide to purify the ore prior to conversion to the oxides. Most often, the chemical formula for yellowcake is described as ammonium diuranate. It is a yellow powder, with consistency of flour. It can be confused with UO2, which is also yellow, and dried uranyl nitrate. It turns out that yellowcake is much more complicated than simply a pure ammonium diuranate molecule, and consists of a mixture of several ammonium-uranium-oxygen compounds. Because of the complex mixture, the uranium content of yellowcake can vary widely, though typically in the range of 40-60%. Pure U3O8 has a consistent uranium content of around 85%, with some minor variability. I can provide references, though they are copyrighted and perhaps can not be posted on this web site.


 * Hmm... there are a lot of websites, including some government ones, which explicitly say that yellowcake *is* U3O8 (try Googling for "yellowcake U308"). Having said that, I see that Britannica says the following: "Uranium is usually precipitated as ammonium diuranate, (NH4)2U2O7. From alkaline solutions, uranium is most often precipitated by addition of sodium hydroxide, producing an insoluble sodium diuranate, Na2U2O7. It can also be precipitated by acidification (to remove carbon dioxide) and then neutralization (to remove the uranium) or by reduction to less soluble tetravalent uranium. In all cases, the final uranium precipitate, commonly referred to as yellow cake, is dried. In some cases—e.g., with ammonium diuranate—the yellow cake is ignited, driving off the ammonia and oxidizing the uranium to produce uranium trioxide (UO3) or the more complex triuranium octoxide (U3O8)." So who's right here? Britannica does sounds more authoritative... -- ChrisO 21:03, 19 January 2006 (UTC)
 * I suspect that the definition of yellowcake has been more as an mid-point in the refining process than a strict chemical one. Perhaps we need to split the topic, and make a Triuranium octoxide page. --DV8 2XL 21:27, 19 January 2006 (UTC)

I'm the fellow who wrote "U3O8" is NOT yellowcake - just registered and have a user name now. Britannica is correct. Sadly, as I know all too well, many DOE folks incorrectly use the term yellowcake to refer to U3O8, UO3, UO2 and the ammonium diuranate, though U3O8 is the front runner for mis-usage. This is odd as U308 is black, while U03 is a bright yellow and can easily be mistaken for yellowcake (I suspect that is what you have a photo of - upon exposure to moisture in the air the U03 color changes slowly to a more orange). Here's a solid technical literature reference: " 'Yellow cake', a bright yellow material, was formerly thought to be ammonium diuranate, and indeed analytical results show this to be the approximate composition. However, it was shown that 'yellow cake' is a mixture of the following compounds: ..." then there's a whole bunch of uranium compounds of varying stoichiometries. This can be found in The Chemistry of the Actinide Elements, 2nd Ed, Katz, Seaborg and Morss; page 276 (that's Glenn Seaborg, nobel prize winner and "discoverer" of plutonium). Anyway, the fact is the term 'yellow cake' technically refers to the product of the precipitation of uranium from processed ores. Yellow cake, referred to as the 'final ore refining concentrate' in the text, is of sufficient purity to be used to create U02, U03 and/or U3O8 for use in the fuel cycle or for conversion (via several steps) to UF6 for enrichment, conversion back to an oxide or metal for use in reactors or weapons. For all practical purposes, the composition ammonium diuranate ((NH4)2U2O7 is reasonably accurate. Even U3O8 is an approximation - the stoichiometry (ratio of oxygen to uranium of 8:3) varies significantly depending on how it is fired in the furnace.  I can provide photos of each of the oxide forms and yellowcake if you're interested.  These materials are offered for sale by the laboratory I work for - which is the U.S. government's certifying authority for uranium and plutonium reference materials.  Photo's will show the material in bottles with our label attached.  OK - enough said!

References - Wasn't 'yellowcake' referred to in the Dave Chappelle skit, Black President? Zena Dhark …·°º•ø®@» 08:29, 11 September 2006 (UTC)
 * Stop trying to POV push, OK? --Haizum   μολὼν λαβέ 22:00, 20 December 2006 (UTC)

Glad to see someone speak up about the common mistake of incorrectly identifying "yellowcake" as U3O8. The preponderance of mistatements that yellowcake is U3O8 includes, not only DOE, but numerous documents published by the Nuclear Regulatory Commision (NRC), who really should know better! Britannica is indeed correct. The little chemistry side-bar on the main article really needs to be changed.Xtline (talk) 22:04, 9 September 2008 (UTC)


 * I've changed the "formula" to "variable, see text" as there is no unique formula for yellowcake. However, I wonder where this came from: "Modern yellowcake typically contains 70 to 90 percent triuranium octoxide (U3O8) by weight". If indeed U3O8 is not yellowcake, could it be that they just use U3O8 as a formal way of expressing concentration? (For example, sometimes it is traditional in analytical chemistry to express calcium concentration as CaCO3 regardless of the form that calcium actually has in the sample.) I think I read somewhere that U3O8 could be used for gravimetric analysis of uranium, so that could explain the convention. But I'm just speculating... --Itub (talk) 10:03, 15 September 2008 (UTC)

Your speculation is right on target. U3O8 has long been the standard assay for uranium ore. Traditionally, assays actually extracted the material to be assayed from the ore by wet chemical methods and measured the weight of some precipitate (which may or may not have been present in the original ore). Because UO2 (the nominal formula for uraninite, the most common uranium ore mineral) and UO3 (which is not known to occur in nature) are both difficult to prepare with precise and repeatable stoichiometries (UO2 requires extremely high temperatures and is commonly hyperstoichiometric, UO2+x, and although UO3 is readily made, it is usually very fine grained and absorbes (and reacts with) H2O in the atmosphere; this all makes these compounds unreliable as assay standards). U3O8 on the other hand is stable to both oxidation and hydration (and though the stoichiometry can vary somewhat, e.g., U3O8-y, as noted above, the value for y tends to be pretty small), and it is pretty readily synthesized: evaporate a U-bearing solution (commonly in nitric acid) and cook the residue at about 800 degrees C (the nitrate is volatilized).Xtline (talk) 15:59, 16 September 2008 (UTC)

Can dropping it be dangerous?
If so, a warning should be placed in article. --NEMT 07:17, 3 July 2007 (UTC)
 * Why would it be? --OuroborosCobra (talk) 04:56, 10 May 2008 (UTC)

Yes! Dropping it without protective measures against exposure is dangerous. The validity of Photos showing people "raking" it are dubious at best. For all we know, those photos were of people raking pure sulfur-oxidates and not Uxxx laced compounds that may look similar. In any event, exposure even in small quantities and especially if airborn and inhaled is like smoking hundreds or even thousands of packs of cigerettes at once. Lungs are easily damaged as are certain other internal organs where the enormous Uxxx compounds oxidize into living tissue and sit as cancer time bombs just waiting to go off one decomposition positron at a time! —Preceding unsigned comment added by 207.173.117.166 (talk) 01:08, 30 April 2009 (UTC)
 * That doesn't really make dropping it dangerous, just exposure to it. Whether that exposure is from dropping, or carrying, or what have you is irrelevant. --OuroborosCobra (talk) 08:01, 30 April 2009 (UTC)

No mention of health effects
Mention "Is exposure to uranium yellowcake dangerous?"

This article will be the first place one turns if a truck overturns! Jidanni (talk) 14:08, 4 May 2013 (UTC)
 * No it won't. That's what MSDS is for. --OuroborosCobra (talk) 18:58, 4 May 2013 (UTC)
 * Fine, Keep it out. http://www.world-nuclear-news.org/RS-Companies_quizzed_over_yellowcake_spill-0907127.html says it is toxic.  The common man will not remember MS-whatever in a pinch, and a Google search ends up in a mess. Bye. Jidanni (talk) 13:23, 5 May 2013 (UTC)
 * The common man will not encounter a yellowcake spill, either. Authorities would block such a thing off, because they have MSDS. --OuroborosCobra (talk) 13:47, 5 May 2013 (UTC)
 * Ha, I even got a ride in a yellowcake truck. Jidanni (talk) 01:14, 6 May 2013 (UTC)
 * So what? You still would not be the IC during a spill. --OuroborosCobra (talk) 02:31, 6 May 2013 (UTC)


 * not really, a small amount of it is not super crazy radioactive. You shouldn't eat it though (or carry it around with you). Enough of it and you'll get heavy metal toxicity. A small amount and you're body will process it out (biological half-life) Ottawakismet (talk) 16:51, 12 March 2014 (UTC)

Radioactivity
What is the level of danger to direct exposure to yellowcake? One of the books in the Life Nature Library series, titled The Earth, shows a picture of a worker using a garden rake to move yellowcake for processing, as if raking garden soil. Group29 (talk) 17:25, 9 May 2008 (UTC)


 * When was the picture taken? In the old times, people were less careful about chemical and radiation safety. It is not highly radioactive, but still I think it would be wise to avoid such direct contact! --Itub (talk) 10:06, 15 September 2008 (UTC)

Airborne yellowcake would be as radioactive as any fallout. Therefore breathing it or having exposed contact with it would also be dangerous. Most of the compounds are also toxic to living tissue in non-radioactive ways so ultimately any contact, either by exposure through mishandling or terrorist act is dangerous. Not all yellowcake is the same as mentioned in the chemistry discussion, but it is not an inert material either. You really don't want to handle it, breath it in or come in contact with it under any circumstance unless you are licensed and trained to use it in the uranium refining industry. —Preceding unsigned comment added by 207.173.117.166 (talk) 01:04, 30 April 2009 (UTC)


 * Uranium is not very radioactive, and its main hazard is the chemical toxicity. It is certainly much less radioactive than fallout from a bomb. Paul Studier (talk) 21:34, 30 April 2009 (UTC)

Density
The article says "Although uranium is one of the densest metals on Earth, yellowcake is relatively light, with a density approximately that of elemental sulfur." but the density at the right side says 9.055g/cm3. That is way more dense than sulfur. Yellowcake is denser than copper. Vmelkon (talk) 00:51, 26 April 2011 (UTC)

Color vs images
The article says that yellowcake produced in modern mills is brown or black, yet all the pictures show it as bright yellow. Because of this and the density issue, I'm going to tag the article with Expert-verify.

That said, regarding the density, it may just be that the yellowcake powder, which has significant amounts of air between particles, feels similar to sulfur, though a solid grain will have the enormous specific density of 9. SamuelRiv (talk) 17:11, 28 July 2011 (UTC)


 * The photo captioned "A drum of yellowcake" has been removed. Metadata for the image describes it as "Low-enriched uranium," which falls well outside of the definition of yellowcake used in this article. The substance in the drum is probably a single, relatively pure uranium compound, most likely UO3 judging by the bright yellow color. Piperh (talk) 08:36, 22 November 2012 (UTC)

Possible stable isotopes
The Curies are supposed to have discovered the elements 84Po Polonium and 88Ra Radium by extraction from Yellowcake Ore with an electroscope radiation detector. Has anyone ever examined the ore for the possible existence of any stable isotopes of either 83Bi bismuth or 84Po polonium, and most specifically for a stable isomer of EE84Po210? It would seem to be a good place to look for a stable isotope of either of these two elements.WFPM (talk) 04:45, 8 November 2012 (UTC)


 * I responded to your question about stable isotopes of Po some time ago at Talk:Polonium. (BTW, 210Po doesn't have isotopes; it is an isotope. It has isomers, such as 210mPo, which has a half-life of 263 ± 5 ns.) Double sharp (talk) 11:12, 21 November 2012 (UTC)


 * I think that I might have confused the issue since the Curies evidently didn't take interest in the extracted Uranium product so much as in the remnant radiation existent in the processed residue, which would be where any produced radioactive and/or stable fission or alpha particle emission by products would be found. What they were given and worked on was evidently the waste byproduct of the ore extraction process.WFPM (talk) 17:48, 26 November 2012 (UTC)

Yellowcake and uranium enrichment
The article states "Purified uranium metal (not the uranium oxide) can also be enriched in the isotope U-235. In this process, the uranium is combined with fluorine to form uranium hexafluoride gas (UF6)." This is at odds with the "Preparation" section of the article on uranium hexafluoride which describes a chemical process beginning with U3O8, i.e. uranium oxide, and proceeding through several intermediate compounds to UF6 that is then the feedstock for isotope separation, with no mention of uranium metal at any point in this sequence of reactions. Can someone with professional knowledge and/or experience in this subject area offer an opinion about which of these apparently divergent views is correct?

For that matter, it is not clear why such a detailed description of the rest of the nuclear fuel manufacturing process needs to be given here. Piperh (talk) 09:14, 22 November 2012 (UTC)

Cake?
I find it very hard to believe anyone would make cake out of highly radioactive substances. Maybe I'm missing something here, but I would expect consumption of this "Yellowcake" would cause, at the very least, moderate stomach upset. And due to the myriad food allergies, I could see substances such as this "Yellowcake" being potntially deadly to people with sensitive or compromised digestive systems or immune systems. I suppose it is because I am the product of a highly industrialized first-world society, but I do not think consumption of this "Yellowcake" could be a defensible or viable act ANYWHERE in the world.

What viable nutrition is obtained by this "Yellowcake" anyway? Does consumption of cake made from this apparently toxic substance stem from ignorance of nutrition? I am shocked that people eat cake compromised of such poison. I know different cultures are accustomed to different foodstuffs that my culture may find revolting, and that is all well and good and one can argue I need to expand my mind and my palate, but where does common sense take over?\

I also find it distressing that this article makes ABSOLUTELY NO MENTION of the dangers of consuming "Yellowcake." I also find it distresing that no mention is made of the confusing nature inherent in referring to it as "Yellowcake" when it makes one think of a more traditional yellow cake made from traditional cake batter, rather than this toxic and potentially dangerous substance. I know Wikipedia is not meant as a soapbox but don't we have a duty as human beings to inform others when something may potentially harm their being? That's my 0.02 American Dollars. — Preceding unsigned comment added by 50.200.48.190 (talk) 17:17, 19 December 2012 (UTC)


 * LOL! Very funny. 64.134.71.74 (talk) 19:49, 7 July 2013 (UTC)


 * hilarious. I guess they what they read.

Radioactive?
Is this substance radioactive? I mean, is it toxic to be around or is it an inert compound? The question came up on another Wiki page when a BLP page asserted that this individual had smuggled this substance and there were questions of whether this could happen without security precautions. 64.134.71.74 (talk) 19:45, 7 July 2013 (UTC)


 * I worked with uranium acetate as a student and it was a normal chemistry lab, without the security and safety things you would expect for dangerously radioactive substance. Uranium ore is not that dangerous either. So the yellowcake in a tight plastic bag in by backpack in an air plane would make a nice present.--Stone (talk) 20:00, 7 July 2013 (UTC)
 * sigh. Stone, I don't know what you are on about with your last sentence. Yes, Yellowcake is radioactive. That you worked with uranium acetate and did not take radiation precautions is not a sign of lack of radioactivity. First, what isotope were you working with? Second, being "radioactive" doesn't automatically mean you need to take precaution. Radioactive just means that you are dealing with a substance that has a half life and will decay, but that halflife can be very long and the radioactivity very low. For the most common isotope of uranium, that is the case, and while it will be radioactive, it may not be highly so. Whether yellowcake radioactivity is high enough to be dangerous is beyond my experience level. It is more concentrated than uranium ore, and is used as a feedstock for radioactive Uranium 235 (which was probably nearly absent from the uranium acetate Stone worked with), and therefore must contain, as a portion of its makeup, radioactive uranium 235. --OuroborosCobra (talk) 13:13, 8 July 2013 (UTC)
 * yes, it is radioactive, but it is not highly active, and there are many many things that would be considered MUCH more radioactive, and require greater precautions. Yellowcake is essentially 99%+ uranium-238, and has a long half-life ~4.5 billion years, so it is one of the most stable radioactive elements around, so both of the previous comments are correct. It is radioactive, and is not highly radioactive, and does not require protection to work with a small amount. Ottawakismet (talk) 16:56, 12 March 2014 (UTC)

Safety?
The safety section contains a paragraph stating that "The danger of yellowcake is primarily associated with its acquisition by a state intent on producing nuclear weapons, who does not have fissile material, but already has an enrichment plant and weaponization capabilities." This does not seem to be a safety consideration for the material itself. — Preceding unsigned comment added by 67.188.230.128 (talk) 05:56, 17 December 2014 (UTC)

"The uranium in yellowcake is almost exclusively (>99%) U-238, with very low radioactivity." Surely this is only relative to enriched uranium, rather than to matter in general? Michaelgraaf (talk) 16:12, 29 January 2022 (UTC)