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What is Yellowcake?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

Yellowcake, known as U3O8 to chemists, is a product obtained by treating uranium ore. Raw uranium ore does not usually contain very high concentrations of this useful mineral, so it must be refined to purify it and concentrate the uranium. The production of yellowcake is one step in the refinery process. This product is traded as a commodity in markets in several corners of the world, and some governments have expressed concerns about the production and sale of yellowcake because it can be used in the production of nuclear weapons.

Mills generate yellowcake by pulverizing the ore they mine and then leaching it with acidic chemicals to create a concentrated material which may be additionally refined and purified, depending on the source and the impurities which are present. As the name implies, yellowcake can indeed be yellowish to orange in color, with some mills producing brown, gray, or black yellowcake. It is often stored in large drums so that it can be conveniently inventoried, handled, and moved.

Scientist with beakers
Scientist with beakers

Also known as urania, yellowcake can be further refined for use in nuclear power plants such as those used to generate electricity and energy for submarines. Urania can also be enriched for use in specialized reactors, and in the construction of weapons. However, enrichment is far from a simple task, requiring specialized facilities, skills, and chemicals, so the average person on the street would be unable to take a drum of yellowcake and turn it into something dangerous. This makes the fears about dissemination of urania less worrisome, although this substance is still not necessarily something which should be readily available to anyone who wants it.

Yellowcake is radioactive, which means that special precautions must be taken when processing, handling, storing, and transporting it. Like other radioactive substances, urania can cause health problems if people are exposed to it, and it could be a serious pollution hazard if it was released into the environment in large amounts. Theoretically, yellowcake could be used to make a dirty bomb, with conventional explosives being used to distribute urania to contaminate an area and cause widespread fear.

Urania production is also a messy and potentially polluting process. The unwanted byproducts of refining, known as tailings, must be contained in some way and eventually disposed of, or they will make their way into the ground and into waterways, causing environmental issues. The mining industry sometimes finds itself under fire for failure to contain pollutants and control refinery sites.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllTheScience researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllTheScience researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments


@ AllenJo: Strictly speaking Saddam did not attack his own people. They were Kurds, who incidentally, rightly or wrongly, are by any real definition of the word, terrorists, having waged a separatist war against Turkey and Iraq for decades.

I note at this point that USA couldn't have cared less about the genocide of the Tamils in Sri Lanka by their own government.


How is the yellowcake transported from one country to the next to begin the process?


@allenJo - I would like to remind you that it was later discovered that Iraq was not among the buyers of yellow cake uranium from Niger, as was initially thought.

The President finally conceded this assertion was based on faulty intelligence. So yes, Iraq was still a sponsor of terror, but the very basis of the Iraq war – or at least the linchpin argument – proved to be wrong.

I think that we need more than purchases on the uranium market to convince any nation that another nation is pursuing a nuclear weapons program.


@hamje32 - I disagree. I think that with Iraq, we had palpable evidence that such a nation had engaged in terrorism before, using chemical weapons on its own people.

I think it would have been hard for them to hide behind the guise of peaceful uses of nuclear energy. Iran used that approach, and they are not credible either in my opinion, although at least they don’t have the track record that Iraq did.


The production of yellowcake uranium was one of the warning flags that the United States looked for in tracking down nations that it thought might be sponsors of terrors. The biggest culprit after the September 11, 2001 terrorist attacks, in this regard, was Iraq.

Some people believe that Iraq never really sought production of yellowcake, as the administration popularly thought; other people believe that they did.

I tend to think that Iraq did want to pursue a nuclear weapons program, however the problem is not just finding proof, but also determining what the intent was.

As the article makes clear, uranium can be used in nuclear energy to generate electricity. I think it is harder to prove that the intentions were for anything other than civilian use.


I do not know much about yellowcake, I have only known about it via a report about Japan's crisis following the tsunami and earthquake. I, like you, was surprised by the name so I thought I would check it out to make sure I had heard right on the news report.

The news report stated that Japan received a lot of its yellowcake from a part of Australia so that would indicate, I think, that Japan's plants did have something to do with yellowcake.


Did anybody else come to this article thinking they were going to learn more about their favorite cake flavor? I have always loved yellow cake with chocolate icing, and thought I might find out more about it and instead I learn how they use names like 'yellowcake' for nuclear reasons! Wow.

I wonder if this was a concern with the nuclear power plants in Japan in the wake of the destruction of the tsunami?

I have read and heard accounts of how the country has pulled together, for example in Tokyo, they were not able to use air conditioning very much secondary to the decrease in power, but the reports were that no one complained because they felt is was a small price to pay in comparison to those who lived closer to the tsunami.

And then you have the Japanese women's national soccer team come from out of nowhere to win the world cup as they were bolstered by what had happened to their country. I am thoroughly impressed.

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