The Power of Uranium

By Johnny W. Lee

The Source of Nuclear Power and Waste—Uranium

The source of nuclear power starts off with the element uranium. Uranium is a radioactive metal that is found throughout the Earth’s crust, it is present in our soil, in our rivers, and in our bedrock. The metal can be found in “concentrations of about four parts per million (ppm) in granite, which is about 60% of the Earth’s crust” according to World Nuclear. The main source of uranium is through underground mines, they are 120 meters in depth where the uranium is excavated along with the bedrock. The ore is then crushed into a fine powder and processed to produce triuranium octoxide (a type of uranium oxide, also known as yellowcake or urania)—a solid.

In 1940s shortly after the end of World War II, the United States promoted uranium mining due to the nuclear arms race with the Soviet Union. The land that happen to contain the richest uranium deposits in the United States was in the southwest—the Navajo Nation. Mining began here shortly after. The Environmental Protection Agency states, “From 1944 to 1986, nearly four million tons of uranium ore were extracted from Navajo lands under leases with the Navajo Nation.” By stating that four million tons of uranium ore was mined during this time it gives the reality of how much was taken from the land. Furthermore, the Environmental Protection Agency states, “potential health effects [from the uranium mines] include lung cancer from inhalation of radioactive particles, as well as bone cancer and impaired kidney function from exposure to radionuclides in drinking water.” Many of these miner where the Navajo people themselves who would live near these toxic mines and rise their families at the same time.  

A New York Times article written by Dan Frosch in 2009 titled, Uranium Contamination Haunts Navajo Country, continues to talk about the effect of uranium mining. Frosch reports, “The Slowman home [Navajo residence], the same one-level cinderblock structure his family had lived in for nearly a half-century, was contaminated with potentially dangerous levels of uranium from the days of the cold war.” The process of obtaining uranium is a high cost for the livelihood of the Navajo people and the waste that’s still left behind in their land.  This was a result of the lack of information that the Navajo people received during the mass mining era of 1940s to 1980s. Frosch continuous to mention, “many miners died from radiation-related illnesses; some, unaware of harmful health effects, hauled contaminated rocks and tailings from local mines and mills to build homes for their families.” Frosch portrays the remains of the uranium mining era still haunts the Navajo people greatly and their struggles continuous to this day. 

Processing Uranium Ore into Fuel

Once the ore is mined it is then crushed into a fine powder and processed to produce triuranium octoxide. Triuranium octoxide contains two different forms (isotopes) of uranium—uranium–235 and uranium–238. Uranium–235 can undergo fission, splitting of the atom, which release heat (energy) while uranium–238 doesn’t undergo fission directly (indirectly though formation of fissionable plutonium-239 within the reactor). Triuranium octoxide, however, is not directly useable as a fuel since contains roughly only 1% of uranium–235. In order to use it as a fuel it has to be enriched by increasing the ratio of uranium–235 in triuranium octoxide. The enrichment process consist of turning the triuranium octoxide, a solid, into hex (uranium hexafluoride), a gas, since it is easier to separate the isotopes of uranium as a gas. The gaseous mixture is then separated to have roughly 5% uranium–235 and it is later converted back into uranium oxide, a solid that is enriched to contain more uranium-235 than naturally. Further enriched to as high as 90% uranium-235 is used as weapon–grade uranium in the making of nuclear weapons. 

The uranium oxide solid is pressured to form small pellets which are encased in metal tubes to form fuel rods of the nuclear reactor. Within the core of the reactor is the uranium–235 which undergoes fission to produce heat in a continuous process (chain reaction). Usually a reactor with an output of 1000 megawatts (MWe), “the core would contain about 75 tonnes of enriched uranium,” according to World Nuclear. Inside the core of the nuclear reactor contains thousands of fuel rods which is surrounded by water. A nuclear reactor generates energy through the heat released from the fission of uranium–235 which turns the surrounding water into steam which leads to the turbines moving to generate electricity. If there is not enough water, however, the heat from the fission reaction will start melting the core which can lead to a nuclear meltdown.

In 2011 after a magnitude 8.9 earthquake due to the sudden movement of the Pacific tectonic plate a tsunami followed shortly in Japan. This caused a series of nuclear meltdown at Fukushima I Nuclear Power Plant in Fukushima, Japan. The results from this disaster shows the veiled dangers of nuclear power. In the social media site, twitter, the hashtag #fukushima is still being used today to report the aftermath of this disaster. In twitter, TEPCO, the Tokyo, Japan Electric Power Company, tweets “TEPCO reports 1st data inside unit 1 reactor bldg, using cosmic-ray ‘muon’ to create x-ray style images,” which reports the aftermath of reactor 1 reveling that it has indeed had a meltdown. 

This was one of the worst–case scenario with nuclear power, but a 172–page report from World Health Organization mentions it was actually an example of how safe nuclear energy is. In the report they mention, “The present results suggest that the increases in the incidence of human disease attributable to the additional radiation exposure from the Fukushima Daiichi NPP accident are likely to remain below detectable levels.” The way nuclear power is presented here shows the portrayal of this disaster is not as bad as one might think. 

The Remains of the Fuel—Uranium Waste

Typically overtime the amount of uranium–235 in the fuel rods will decrease as it undergoes fission to produce heat. “To maintain efficient reactor performance, about one-third of the spent fuel is removed every year or 18 months, to be replaced with fresh fuel,” according to World Nuclear. The spent fuel is processed for either reprocessing (recycled) or put for long-term storage (chemical waste). Spent fuel contains mainly uranium-238 which can’t undergo fission and highly radioactive chemicals products from the fission of uranium–235. The uranium-238 can be separated from these chemical side products and be enriched again to make more fuel. The chemicals side products, however, can’t be reused and store in chemical waste sites. “At the present time, there are no disposal facilities (as opposed to storage facilities) in operation in which used fuel, not destined for reprocessing, and the waste from reprocessing, can be placed. In either case the material is in a solid, stable waste form,” according to World Nuclear.

A YouTube video title, Wasteland: The nuclear graveyard under New Mexico, continues to enforce the previous statement by stating that over 70,000 tons of nuclear waste is sitting outside nuclear power plants throughout the country—there is no viable solution yet. The video shows a series of clips of politicians scramming for a solution, but again the message of the videos shows—there is no solution, only more ways to store the waste deep underground. The video mentions the nuclear waste policy act of 1987. The aim of that act was at storing the spent nuclear fuel in the repository in the United States at Yucca Mountains in Nevada. Ever since 2009, however, the Obama administration has been attempting to shut down the repository site. 

Another view is presented from Science Magazine in an article titled, “Yucca Mountain nuclear waste repository passes major hurdle” by Eli Kintisch in 2014. In the article Kintisch speaks about “a key safety evaluation published yesterday by the Nuclear Regulatory Commission (NRC) gives it [Yucca Mountains] a thumbs up.” He writes about a 781–page report that describes how safe Yucca Mountains will be for isolating the radioactivity from the environment for thousands of years. He portrays the debate on Yucca Mountains as in favor by highlight the view point form supports of storing waste on Yucca Mountains. As an example he mentions “This technical evaluation provides strong support for our belief that the Yucca Mountain site is appropriate for an underground repository for used nuclear fuel.” 

The Fate of Nuclear Power 

From the beginning of mining the uranium from the Earth to the end where we burry it back in to the Earth there is quite a few problems along the way. Written here is simply one portrayal of problems that comes along with nuclear power. While many have suffered from nuclear power such as the Navajo (obtaining uranium), people of Fukushima (using uranium), and the people who live near Yucca Mountains (storing and disposing uranium) many others have greatly benefited as well. There is no perfect source of energy and from each and every one it has its own advantages and disadvantages.  Ultimately, nuclear power provides the ability to generate a vast amount of energy with relatively small carbon footprint, but there is always an inherent risk with nuclear power.