Nuclear weapons get their power from a nuclear chain reaction. To achieve this, so-called fissile material — material capable of sustaining a nuclear chain reaction — is needed. The most common materials used in nuclear weapons are the two radioactive elements uranium (U) and plutonium (P), both of which contain fissile atomic nuclei.
The isotopes uranium-235 and plutonium-239 are the most common forms of these elements that are used in nuclear weapons. Uranium occurs as a natural element in soil and bedrock, and mainly consists of two isotopes, U-235 and U-238. Plutonium, on the other hand, is only found in very small amounts in nature and is therefore created synthetically in nuclear reactors from uranium-238.
Both uranium and plutonium are radioactive substances with long half-lives. The half-lives of uranium-235 and uranium-238 are about 700 million and 4.5 billion years respectively, while plutonium-239 has a relatively shorter half-life of 24,000 years. This means that it takes that long for the substance to become half as radioactive as it is today. Once it gets out into nature, in other words, the substance remains there effectively forever.
Uranium mining is the first step in the process of developing nuclear weapons. Uranium ore is found in the bedrock and can be extracted in different ways; at the surface in open pits, in underground mines, or by chemically filtering uranium from ore with low levels of uranium (so-called in situ leaching).
Uranium ore is mined in a few countries. The largest mines are in Canada and Australia, but uranium is also mined in Namibia, South Africa, Kazakhstan, Uzbekistan and Russia.
Consequences of uranium mining
Mining of uranium ore has consequences for both the environment and human health.
In addition to damaging the landscape, mining leaves behind millions of tons of hazardous waste products. These residual products are called “tailings”. Every ton of uranium oxide produced leaves thousands of tons of environmentally hazardous waste behind.
This waste poses serious environmental and health risks in the form of emissions of heavy metals, radioactive gases such as radon, and radioactive dust.
The waste is often left lying on the ground near the mine, where it risks leaking out further when wind and water are added to the mix. The wind can carry the radioactive gases and dust for several kilometers. Contaminated rainwater makes its way into the soil and ultimately into the groundwater, where it enters the food chain.
People can be affected by, for example, contaminated drinking water or when they inhale radioactive gases and radioactive dust. Research has shown that people who worked in uranium mines had a higher risk of suffering from severe health issues, like lung cancer and damage to the liver and kidneys.
In many cases, uranium mining takes place in areas where Indigenous peoples live. Mining has destroyed local communities and environments in North America, Australia, Africa and Asia. Land belonging to Indigenous peoples has also been used to dump radioactive waste and to test nuclear weapons. This has resulted in massive environmental destruction and radioactive contamination.
Navajo Land in the southwestern United States
The area in the southwestern United States where the Indigenous Navajo people, along with other Indigenous tribes like the Hopi, live has been hit hard by the consequences of uranium mining. The land of the Navajo people is located in the middle of a belt where uranium mining took place for several decades from the 1940s to the 1980s, and waste from the mining left on their land has destroyed the health of entire communities. Approximately 30 percent of the population lacks access to clean water due to contamination from uranium mining.
Uranium mining workers in the USA have shown a much higher percentage of cancer patients than the rest of the population. The incidence of lung cancer is as much as 40 times greater than expected in the normal population. The workers were not warned about the dangers of radioactivity, nor given proper protective gear.
Niger and Namibia
In Niger and Namibia, residual products from the uranium mines have been left on the ground in the desert sand, contaminating air, food and drinking water for people who live and move in the areas. The vegetation and animal life in the areas have also been affected.
Saskatchewan in Canada
In northern Saskatchewan in Canada, there are the world’s largest and most concentrated uranium deposits. Here, the industries that mined the ore, both routinely and accidentally, have left behind contaminated water from uranium mining and milling. Large fisheries have been poisoned and the health of the Indigenous people living off nature in the area is seriously threatened.
Australia has one third of the world’s recoverable uranium resources. Mining began in the 20th century and intensified during the Second World War when the production of nuclear weapons began. As of 2021, there are only two uranium mines in Australia after major protests from the Indigenous population and environmental organizations.
The nuclear fuel chain
The nuclear fuel chain refers to the steps required to obtain material for nuclear weapons and fuel for nuclear power plants.
The first step to obtaining a nuclear weapon is the mining of uranium.
The next step is to extract uranium concentrate, so-called yellow cake, from the ore. It is done by grinding the uranium ore into a fine powder which is then leached to remove all unnecessary elements and extract uranium concentrate.
The uranium found in nature has a very low content of U-235 (only 0.7 percent), which is the isotope that is the easiest to fission and thus the most useful. To reach weapons grade 90 percent U-235 is required.
For the uranium to be useful, the uranium concentrate therefore needs to be enriched, a process that involves raising the content of the necessary isotope U-235. The uranium to be used in nuclear power reactors needs to be enriched to approx. 3–5 percent U-235. For use in nuclear weapons, an enrichment to around 90 percent is needed.
Uranium enrichment consists of large-scale industrial processes that require large spaces and are difficult to hide from countries that may want to keep their enrichment facilities secret. The most common enrichment method is centrifuges.
The same type of centrifuges are used to enrich uranium for nuclear power as for nuclear weapons, the only difference being the degree of enrichment. It is therefore relatively easy to produce uranium for nuclear weapons in a facility that was originally intended for nuclear reactor fuel production.
When uranium is used in a nuclear reactor, a new element, plutonium, is formed. The plutonium isotope Pu-239 can be used in nuclear weapons. Through a process called reprocessing, this plutonium can be extracted from the nuclear waste. Plutonium residues from nuclear power reactors for energy production can thus be used to build a nuclear weapon.
Depleted uranium is a toxic byproduct of enriching uranium for nuclear power or nuclear weapons. Depleted uranium is used militarily as armor-piercing ammunition and as reinforcement in tank armor shells. When ammunition containing depleted charges explodes, uranium oxide dust is released which affects the surrounding environment.
Weapons with depleted uranium do not count as a nuclear weapon, but still have high levels of radiation. Use of depleted uranium in weapons therefore has major health consequences for the population in the areas where the weapons are used. Use leaves behind radioactive dust that can seep into the soil and groundwater and can travel long distances by wind. When people breathe in the radioactive dust, it is stored in the lungs, staying there for life and possibly leading to cancer or other health issues. The particles can also be stored in bones, lymph nodes, liver, kidneys and other organs and tissues.
Sources and more information
Depleted Uranium, International Atomic Energy Agency, IAEA
Navajo Nation: Cleaning Up Abandoned Uranium Mines, United States Environmental Protection Agency, EPA
Radioactive Waste From Uranium Mining and Milling, United States Environmental Protection Agency, EPA
Left in the Dust – uranium mining in Niger, Greenpeace
Nuclear Weapons Production, International Campaign to Abolish Nuclear Weapons, ICAN
Nuclear Testing in Australia, International Campaign to Abolish Nuclear Weapons Australia, ICAN Australia
Uranium Mining, Gundjeihmi Aboriginal Corporation
Depleted Uranium, United Nations Office for Disarmament Affairs, ODA
Depleted Uranium, Britannica