Nuclear fuel

Uranium

Uranium is the 92nd element on the periodic table, and is the heaviest naturally occurring element on Earth. It is known for being an abundant source of concentrated energy, with the largest energy density of any of the world’s fuels used for the generation of electricity.

Uranium is found relatively commonly on the Earth, with an abundance of 2.8 parts per million in the crust. This makes it more common than gold, as common as tin, and less common than copper. 99.3% of the uranium found on Earth is Uranium-238 which is “fertile”, while the rest (0.7%) is Uranium-235, a “fissile” fuel. Therefore only a very small amount of the uranium found naturally can be used in a nuclear fission process unless it undergoes an enrichment process, which increases the concentration of Uranium-235, or the Uranium-238 is “bred” from its fertile form into

Uranium makes for an excellent nuclear fuel, and is used as the primary fuel in nuclear reactors all over the world. In this section, uranium’s fuel cycle will be briefly explored.

How is nuclear fuel generated?

A clean energy resource
Nuclear energy originates from the splitting of uranium atoms – a process called fission. This generates heat to produce steam, which is used by a turbine generator to generate electricity.

nuclear power plants are very similar to coal-fired power plants. However, they require different safety measures since the use of nuclear fuel has vastly different properties from coal or other fossil fuels. They get their thermal power from splitting the nuclei of atoms in their reactor core, with uranium being the dominant choice of fuel in the world today. Thorium also has potential use in nuclear power production, however it is not currently in use. Below is the basic operation of a boiling water power plant, which shows the many components of a power plant, along with the generation of electricity.

Nuclear Reactor

The reactor is a key component of a power plant, as it contains the fuel and its nuclear chain reaction, along with all of the nuclear waste products. The reactor is the heat source for the power plant, just like the boiler is for a coal plant. Uranium is the dominant nuclear fuel used in nuclear reactors, and its fission reactions are what produce the heat within a reactor. This heat is then transferred to the reactor’s coolant, which provides heat to other parts of the nuclear power plant. Besides their use in power generation, there are other types of nuclear reactors that are used for plutonium manufacturing, the propulsion of ships, aircraft and satellites, along with research and medical purposes. The power plant encompasses not just the reactor, but also cooling towers, turbines, generators, and various safety systems. The reactor is what makes it differ from other external heat engines.

Steam Generation

The production of steam is common among all nuclear power plants, but the way this is done varies immensely. The most common power plants in the world use pressurized water reactors, which use two loops of circling water to produce steam. The first loop carries extremely hot liquid water to a heat exchanger, where water at a lower pressure is circulated. It then heats up and boils to steam, and can then be sent to the turbine section.

Boiling water reactors, the second most common reactor in power generation, heat the water in the core directly to steam, as seen in Figure 2.

Turbine and Generator

Once steam has been produced, it travels at high pressures and speeds through one or

more turbines. These get up to extremely high speeds, causing the steam to lose energy, therefore, condensing back to a cooler liquid water. The rotation of the turbines is used to spin an electric generator, which produces electricity that is sent out the the electrical grid.

Cooling Towers

Perhaps the most iconic symbol of a nuclear power plant is the cooling towers, seen in Figure 4. They work to reject waste heat to the atmosphere by the transfer of heat from hot water (from the turbine section) to the cooler outside air. Hot water cools in contact with the air and a small portion, around 2%, evaporates and raises up through the top. Moreover, these plants do not release any carbon dioxide—the primary greenhouse gas that contributes to  climate change.  Many nuclear power plants simply put the waste heat into a river, lake or ocean instead of having cooling towers. Many other power plants like coal-fired power plants have cooling towers or these large bodies of water as well. This similarity exists because the process of turning heat into electricity is almost identical between nuclear power plants and coal-fired power plants.

Can nuclear power be used as fuel?

Nuclear Fission Creates Heat
Reactors use uranium for nuclear fuel. The uranium is processed into small ceramic pellets and stacked together into sealed metal tubes called fuel rods. Typically, more than 200 of these rods are bundled together to form a fuel assembly.

Is nuclear fuel cheaper than coal?

Generally, a nuclear power plant is significantly more expensive to build than an equivalent coal-fueled or gas-fueled plant. If natural gas is plentiful and cheap, the operating costs of conventional power plants is less.

Is nuclear fuel better than coal?

Nuclear Has The Highest Capacity Factor
This basically means nuclear power plants are producing maximum power more than 92% of the time during the year. That’s about nearly 2 times more as natural gas and coal units, and almost 3 times or more reliable than wind and solar plants.

Is nuclear fuel renewable?

Although nuclear power is not a renewable energy, it is still recyclable. Thanks to Orano’s technologies, unique in the world on an industrial scale, 96% of spent nuclear fuel in reactors is recyclable. MOX, an assembly produced from recycled spent fuel, has already been used to supply 44 reactors around the world.

How efficient is nuclear fuel?

Nuclear Power Compared to Other Types of Energy
Nuclear power is already one of the most efficient types of energy available today. An average capacity factor of 91 percent beats other energy forms by a substantial margin. Natural gas produces an average of 50 percent while coal produces energy at almost 59 percent.

advantages 

The advantages of nuclear power are:

  • One of the most low-carbon energy sources
  • It also has one of the smallest carbon footprints
  • It’s one of the answers to the energy gap
  • It’s essential to our response to climate change and greenhouse gas emissions
  • Reliable and cost-effective

CLEAN ENERGY SOURCE

Nuclear is the largest source of clean power in the United States. It generates nearly 800 billion kilowatt hours of electricity each year and produces more than half of the nation’s emissions-free electricity. This avoids more than 470 million metric tons of carbon each year, which is the equivalent of removing 100 million cars off of the road.

CREATES JOBS

The nuclear industry supports nearly half a million jobs in the United States and contributes an estimated $60 billion to the U.S. gross domestic product each year. U.S. nuclear plants can employ up to 700 workers with salaries that are 30% higher than the local average. They also contribute billions of dollars annually to local economies through federal and state tax revenues.

SUPPORTS NATIONAL SECURITY

A strong civilian nuclear sector is essential to U.S. national security and energy diplomacy. The United States must maintain its global leadership in this arena to influence the peaceful use of nuclear technologies. The U.S. government works with countries in this capacity to build relationships and develop new opportunities for the nation’s nuclear technologies.

Consistent source of energy

Nuclear power has a consistent and predictable output. It is not affected by weather conditions compared to other sources such as wind and solar power. Nuclear fission generates far more energy than fossil fuel combustion such as coal, oil, or gas. The process produces almost 8,000 times more power than typical fossil fuels, resulting in less material used and causing less waste. All-year-round energy production is feasible, allowing for favorable returns on initial investment due to no energy production delays. It is estimated the world has enough uranium to produce electricity for the next 70-80 years. It does not seem like a long enough period, but in comparison to fossil fuels, they are expected to diminish in a far less period. Additionally, there are current investigations into alternative power sources for nuclear energy.

Why use nuclear energy?

There’s a huge and ongoing demand for electricity in the UK. Think about your everyday routine and how much of that relies on energy. We have a responsibility to keep powering our homes, workplaces and cities – but we also have a responsibility to the planet. So we need to make sure we are low-carbon and environmentally friendly.

Although nuclear power stations take considerable investment to build, they have low running costs and longevity. This means they are particularly cost-effective. Most of the carbon dioxide (CO2) emissions associated with nuclear power stations happen during construction and fuel processing, not when electricity is being generated.

Nuclear can help meet our demands Uranium is the raw material used to create fuel – it comes from stable regions around the world and is widely available. This dependability means nuclear power is a long-term and low-carbon option.

However, we need enough power stations to process it. They last between 40 and 60 years after which they are decommissioned. Seven of the eight nuclear power stations in the UK are due to close by 2030. These create enough electricity to power 50% of the UK’s homes (or around a fifth of all the electricity used in the UK). Nuclear energy isn’t only low-carbon, it’s also reliable when compared to other low-carbon options. So when the sun doesn’t shine or the wind doesn’t blow, nuclear takes over keeping the lights on around the UK.

Disadvantages

Analysis

New nuclear power costs about 5 times more than onshore wind power per kWh. Nuclear takes 5 to 17 years longer between planning and operation and produces on average 23 times the emissions per unit electricity generated. In addition, it creates risk and cost associated with weapons proliferation, meltdown, mining lung cancer, and waste risks. Clean, renewables avoid all such risks.

There is a small group of scientists that have proposed replacing 100% of the world’s fossil fuel power plants with nuclear reactors as a way to solve climate change. Many others propose nuclear grow to satisfy up to 20 percent of all our energy (not just electricity) needs. They advocate that nuclear is a “clean” carbon-free source of power, but they don’t look at the human impacts of these scenarios. Let’s do the math…

One nuclear power plant takes on average about 14-1/2 years to build, from the planning phase all the way to operation. According to the World Health Organization, about 7.1 million people die from air pollution each year, with more than 90% of these deaths from energy-related combustion. So switching out our energy system to nuclear would result in about 93 million people dying, as we wait for all the new nuclear plants to be built in the all-nuclear scenario.

Utility-scale wind and solar farms, on the other hand, take on average only 2 to 5 years, from the planning phase to operation. Rooftop solar PV projects are down to only a 6-month timeline. So transitioning to 100% renewables as soon as possible would result in tens of millions fewer deaths.

This illustrates a major problem with nuclear power and why renewable energy — in particular Wind, Water, and Solar (WWS)– avoids this problem.

What are three disadvantages of nuclear fuel?

Cons of Nuclear Energy

  • Expensive Initial Cost to Build. Construction of a new nuclear plant can take anywhere from 5-10 years to build, costing billions of dollars. …
  • Risk of Accident. …
  • Radioactive Waste. …
  • Limited Fuel Supply. …
  • Impact on the Environment.

Why nuclear energy is not a good idea?

Nuclear takes 5 to 17 years longer between planning and operation and produces on average 23 times the emissions per unit electricity generated. In addition, it creates risk and cost associated with weapons proliferation, meltdown, mining lung cancer, and waste risks. Clean, renewables avoid all such risks.

Impact on the environment

The most significant impact on the environment stems from the destructive process of uranium mining. Both open-pit and underground mining can mine uranium. Open-pit mining is generally a safe process for miners but generates radioactive waste while causing erosion and, on some occasions, polluting water supplies. Underground mining exposes miners to a far greater risk of radiation poisoning than open-pit mining. While also producing large amounts of the radioactive waste rock during both processing and extraction.

Weapons Proliferation Risk

The growth of nuclear energy has historically increased the ability of nations to obtain or harvest plutonium or enrich uranium to manufacture nuclear weapons. The Intergovernmental Panel on Climate Change (IPCC) recognizes this fact. They concluded in the Executive Summary of their 2014 report on energy, with “robust evidence and high agreement” that nuclear weapons proliferation concern is a barrier and risk to the increasing development of nuclear energy:

Barriers to and risks associated with an increasing use of nuclear energy include operational risks and the associated safety concerns, uranium mining risks, financial and regulatory risks, unresolved waste management issues, nuclear weapons proliferation concerns, and adverse public opinion. 

The building of a nuclear reactor for energy in a country that does not currently have a reactor allows the country to import uranium for use in the nuclear energy facility. If the country so chooses, it can secretly enrich the uranium to create weapons grade uranium and harvest plutonium from uranium fuel rods for use in nuclear weapons. This does not mean any or every country will do this, but historically some have and the risk is high, as noted by IPCC. The building and spreading of Small Modular Reactors (SMRs) may increase this risk further.

 Meltdown Risk

To date, 1.5% of all nuclear power plants ever built have melted down to some degree. Meltdowns have been either catastrophic (Chernobyl, Russia in 1986; three reactors at Fukushima Dai-ichi, Japan in 2011) or damaging (Three-Mile Island, Pennsylvania in 1979; Saint-Laurent France in 1980). The nuclear industry has proposed new reactor designs that they suggest are safer. However, these designs are generally untested, and there is no guarantee that the reactors will be designed, built and operated correctly or that a natural disaster or act of terrorism, such as an airplane flown into a reactor, will not cause the reactor to fail, resulting in a major disaster.

 Mining Lung Cancer Risk

Uranium mining causes lung cancer in large numbers of miners because uranium mines contain natural radon gas, some of whose decay products are carcinogenic. A study of 4,000 uranium miners between 1950 and 2000 found that 405 (10 percent) died of lung cancer, a rate six times that expected based on smoking rates alone. 61 others died of mining related lung diseases. Clean, renewable energy does not have this risk because (a) it does not require the continuous mining of any material, only one-time mining to produce the energy generators; and (b) the mining does not carry the same lung cancer risk that uranium mining does.

Waste Risk

consumed fuel rods from nuclear plants are radioactive waste. Most fuel rods are stored at the same site as the reactor that consumed them. This has given rise to hundreds of radioactive waste sites in many countries that must be maintained and funded for at least 200,000 years, far beyond the lifetimes of any nuclear power plant. The more nuclear waste that accumulates, the greater the risk of radioactive leaks, which can damage water supply, crops, animals, and humans.

Conclusion

Nuclear advocates claim nuclear is still needed because renewables are intermittent and need natural gas for backup. However, nuclear itself never matches power demand so it needs backup. Even in France with one of the most advanced nuclear energy programs, the maximum ramp rate is 1 to 5 % per minute, which means they need natural gas, hydropower, or batteries, which ramp up 5 to 100 times faster, to meet peaks in demand. Today, in fact, batteries are beating natural gas for wind and solar backup needs throughout the world. A dozen independent scientific groups have further found that it is possible to match intermittent power demand with clean, renewable energy supply and storage, without nuclear, at low cost.

Finally, many existing nuclear plants are so costly that their owners are demanding subsidies to stay open. For example, in 2016, three existing upstate New York nuclear plants requested and received subsidies to stay open using the argument that the plants were needed to keep emissions low. However, subsidizing such plants may increase carbon emissions and costs relative to replacing the plants with wind or solar as soon as possible. Thus, subsidizing nuclear would result in higher emissions and costs over the long term than replacing nuclear with renewables.

The efficiency of a nuclear power plant is determined similarly to other heat engines—since technically the plant is a large heat engine. The amount of electric power produced for each unit of thermal power gives the plant its thermal efficiency, and due to the second law of thermodynamics there is an upper limit to how efficient these plants can be.

Typical nuclear power plants achieve efficiencies around 33-37%, comparable to fossil fueled power plants. Higher temperature and more modern designs like the Generation IV nuclear reactors could potentially reach above 45% efficiency.

Nuclear power has numerous advantages and disadvantages, causing the contentious argument about whether to find alternatives or preserve the technology for future uses. Nuclear power energy has the potential to be particularly dangerous, however, the risk of disaster is relatively low.

While there is continued debate, enthusiasts of nuclear power have said that being more dependent on nuclear energy will reduce third-country energy reliance. However, reliance would still be necessary as nuclear power facilities still require raw materials such as uranium imported from Kazakhstan, Australia, or Canada.

Adding further contention is the negative connotation surrounding nuclear energy. Largely, individuals are only aware of nuclear disasters and not the potential low-carbon positives. This is where the concept of renewable energy is greatly favored. However, ideally combining the two procedures is expected to be a more feasible approach for future sustainability.

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