If you've been following the news, you may think uranium is only used in nuclear bombs and nuclear power plants. But uranium has lots of other uses. Unfortunately, the Fukushima nuclear reactor meltdown in Japan and North Korea's (and Iran's) continued push for nuclear weapons show the volatile and dangerous nature of this vital element. What's even more frightening that uranium's destructive potential is the fact that several of the countries with the largest uranium reserves could conceivably sell some to North Korea and Iran.

Check out this list of the countries with the world's top uranium reserves.

1. Australia

Australia possesses around 30% of the world's known recoverable uranium reserves. This island nation is the 20th-largest economy in the world and has stable legal and political systems; you might say it's one of the "nice guys."

The stability of Australia makes it a great place for miners to operate. For example, globally diversified giants Rio Tinto plc (NYSE:RIO) and BHP Billiton Limited (NYSE:BHP) both have uranium mines in the country. BHP's Olympic Dam, its only uranium asset, is the largest known uranium orebody in the world. Rio, meanwhile, has an investment in the Ranger Mine.

The nuclear fuel is such a small contributor to BHP's business that the company doesn't even report that segment's results independently. And at Rio, uranium made up just 1.3% of 2016 revenue and 0.4% of EBITDA. That said, Rio's and BHP's uranium mines are the most important in Australia, so the companies play a significant role in the global uranium market. The same is true of Australia, which is better known for commodities like iron ore and coal.

2. Kazakhstan

Kazakhstan is the 42nd-largest economy in the world and the largest former Soviet Republic by area (excluding Russia). Kazakhstan is resource-rich, which helps to explain why its economy is so much larger than those of other Central Asian nations, and 22% of its exports go to neighboring China and Russia. The country also struggles with corruption and a weak banking system.

Kazakhstan contains about 13% of the world's recoverable uranium, with 50 known deposits and around 20 operating uranium mines, so it's a key player in the uranium market. Kazatomprom, a state-owned entity, controls the uranium industry in the country through its own subsidiaries or via joint ventures with foreign companies. One such partner is Cameco Corp (NYSE:CCJ), the world's largest pure-play, publicly traded uranium miner. Cameco's Inkai mine investment is just one of many uranium assets in the miner's portfolio, which spans mining, processing, and brokering.

3. Russia

The third-largest player in the global uranium market is Russia, with about 9% of the world's uranium (it's actually tied with No. 4, Canada). Russia's economy is the seventh-largest in the world, and the U.S. Central Intelligence Agency describes the country as a "centralized authoritarian state ... in which the regime seeks to legitimize its rule through managed elections, populist appeals, a foreign policy focused on enhancing the country's geopolitical influence, and commodity-based economic growth." It's easy to see why Russia's enormous uranium reserves make many world leaders nervous.

Russia is largely seen as supporting countries like North Korea and Iran, either overtly or through political means, e.g., using its veto power on the United Nations Security Council. It has often teamed up with China, which will make a brief appearance later on this list, to soften the world's response to North Korean and Iranian nuclear provocations. State-controlled AtomRedMetZoloto handles all of Russia's uranium mining and exploration activity.

4. Canada

Canada also accounts for around 9% of the world's recoverable uranium. The United States' northern neighbor, like Australia, is generally considered a positive force in the world. Its economy is the 18th-largest in the world. Throughout much of its history Canada has benefited from its proximity to the U.S., which is the end market for more than three-quarters of Canada's exports.

Cameco, which hails from Canada, is the most notable uranium miner in the country. It has a number of investments, but Cigar Lake and McArthur River are two of the largest uranium mines in Canada and the world.

There is vast potential for further uranium development in Canada. For example, Cameco and Denison Mines Corp (NYSEMKT:DNN) are partners in the Wheeler River project. This mine, which isn't expected to start production until 2025, has the potential to be one of the five largest uranium-producing mines in the world.

5. South Africa

From here the list of uranium-rich countries gets a little subjective, because the numbers are fairly close.According to some sources, South Africa has around 6% of the world's developable uranium reserves. Other sources peg its reserves at just lower than the next two countries on the list, Niger and Namibia. Either way, it's in the neighborhood of No. 5 by uranium reserves, and it's a big step down from the top four countries on the list.

South Africa's economy ranks at No. 31 globally. It has long struggled with unemployment, poverty, and inequality. The government, meanwhile, has not been a particularly stable influence. When it comes to mining, the country is better known for platinum, gold, and chromium than for uranium. For example, gold miner AngloGold Ashanti Limited (NYSE:AU) produces uranium in South Africa, but only as a byproduct of its other mining efforts.

South Africa has two nuclear power plants, and there are plans to build a couple more, so there is a potentially growing market for nuclear fuel in the country. Although South Africa will probably never be a major force in the global uranium market, it could be an interesting region to watch -- especially if those new nuclear facilities get built.

6. Niger

Niger has about 5% of the world's known developable uranium reserves. The country has two major mines and hits above its weight class, supplying roughly 7.5% of the world's uranium. France's Areva SA (NASDAQOTH: ARVCF) is a major player in the country, and its Arlit mine is one of the 10 highest-producing uranium mines in the world. Areva has another project in the country that's currently on hold due to low uranium prices.

Niger's is not a large economy, ranking at just 146 globally. Interestingly, uranium is Niger's largest export. According to Areva, uranium represents around 5% of the country's gross domestic product and supplies around 5% of its tax revenues. Niger, however, is a very poor nation and must rely on outside investment for the development of its resources. That's where Areva comes in, though it's worth noting here that China is also involved in developing Niger's uranium assets to a smaller extent.

7. Namibia

Next up is Namibia, which also has roughly 5% of the world's developable uranium resources. Namibia is only slightly larger than Niger, with its economy weighing in at No. 136 worldwide. Its economy, while poor, is more diversified than Niger's: The country exports more diamonds, copper, gold, zinc, than it does uranium. Natural resources are highly important to the nation's economic well-being. Overall, mining accounts for about 11.5% of the country's gross domestic product and provides over half of the country's foreign exchange earnings.

China is a big player in the country, and China's investment there could materially change the face of the uranium market inside and outside Namibia. The CIA expects the Chinese-owned Husab mine to make Namibia the No. 2 uranium producer worldwide. India is also working toward a uranium relationship with the country. Australian-British miner Rio Tinto has a major stake in one of the country's other two major mines as well. Namibia is a country to watch closely as competing forces look to take advantage of its uranium wealth.

8. China

China has around 5% of the world's developable uranium supplies and ranks as the globe's largest economy based on gross domestic product. Some sources place its uranium reserves a little higher than countries like Namibia and Niger, while others rank them a little lower.

The centrally controlled country is a major nuclear power, with 20 nuclear power plants currently under construction (not to mention the ability to produce its own nuclear weapons). As you can see from its investment in Namibia, it is reaching out beyond its borders to ensure it has access to the uranium it needs for its internal use. And because of its size, it has the resources to continue investing to boost its position in the uranium industry.

Perhaps more concerning, China and its neighbor with nuclear ambitions, North Korea, have long been trading partners. China has attempted to protect the autocratic state politically, often allying with Russia in the effort. So while China is nowhere near the top of this list when it comes to uranium reserves, it is already playing an important role globally in mining for uranium and deciding how it gets used. China should probably be higher up on your list of concerns than any of the African nations that have equal or larger uranium reserves, and perhaps even higher than uranium giant Australia.

Tensions are running high

Uranium is a potentially life-altering power source when used conscientiously and carefully. It can provide reliable baseload power without the use of dirty carbon fuels. However, it can also be used to create weapons of mass destruction, which is why most countries around the world would prefer to keep it out of the hands of players like Iran and North Korea.

As you can see from this list, many of the largest uranium reserves are in countries that are democratic, relatively stable, and all-around good geopolitical forces. But some are too corrupt, unstable, or financially weak to fall into that category. If you are interested in the way uranium is getting used around the world, you should be keeping a close eye on at least a few of the countries that made this list.