Untitled Notes

Definition: Nuclear energy is energy that is generated through the use of uranium, a natural metal that is mined all over the world.
Generation Process: Nuclear energy is created through complex processes in nuclear reactions.
Usage: A significant amount of military operations and vessels utilize nuclear power plants and nuclear energy as their energy source. Additionally, nuclear energy provides 16% of the Earth’s energy requirements.

Chemical Properties: Uranium is a silvery-white metallic chemical element with atomic number 92, assigned the chemical symbol U.
Atomic Structure:
- A uranium atom contains 92 protons and 92 electrons, with 6 of these being valence electrons.
- The uranium nucleus has between 141 and 146 neutrons.
Isotopes: There are six isotopes of uranium (U-233 through U-238). The most common isotopes are:
- Uranium-238 (146 neutrons)
- Uranium-235 (143 neutrons)
Occurrence in Nature:
- Natural occurrences of uranium consist of:
- Uranium-238 (99.2742%)
- Uranium-235 (0.7204%)
- Uranium-234 (0.0054%)
- Uranium decays slowly by emitting an alpha particle.
Half-life:
- The half-life of uranium-238 is about $4.47 ext{ billion years}$ .
- The half-life of uranium-235 is about $704 ext{ million years}$ .

Location: Uranium can be found almost everywhere in soil and rock, rivers, and oceans. Traces of uranium are also found in food and human tissue. Concentrated uranium ores are found in select locations, typically in hard rock or sandstone.
Extraction Method: Uranium is recovered through methods such as mining.

Definition: The most commonly used nuclear reaction for power generation is nuclear fission, which is the splitting of an atomic nucleus into parts by capturing a neutron.
Byproducts of Fission: Nuclear fission produces radiation which must also be disposed of.
Chain Reaction:
- Fission produces neutrons, which can then be captured by other atoms to continue the reaction (chain reaction) with more neutrons being produced at each step.
- When the reaction reaches critical mass, the reaction becomes self-sustaining.
- If too many neutrons are generated, the reaction can become unmanageable, potentially leading to an explosion.
Control Mechanism: Control rods are used to absorb the extra neutrons and are interspersed with the fuel rods to manage the reaction.
Common Fuel: Uranium-235 is the most commonly used fuel for fission.

Definition: Nuclear fusion is another method to produce nuclear energy, where two light elements (like tritium and deuterium) are forced to fuse and form helium and a neutron.
- This is the same reaction that fuels the sun and produces light and heat.
Energy Output: Unlike fission, fusion produces much more energy, but its components are more abundant and cheaper than uranium.

Resource Availability: The Earth has limited supplies of coal and oil. Nuclear power can provide electricity even after fossil fuels become scarce.
Fuel Efficiency: Nuclear power plants require less fuel than those burning fossil fuels; one ton of uranium produces more energy than several million tons of coal or several million barrels of oil.
Environmental Impact: Nuclear power plants produce no air pollutants, unlike coal and oil burning plants which contribute contaminants to the air.

Radiation Risk: Nuclear explosions produce radiation, which can harm body cells, leading to sickness or death. Illness can manifest years after exposure.
Nuclear Waste: Reactors produce nuclear waste products that emit dangerous radiation. This waste cannot be disposed of like ordinary garbage and is stored in special cooling pools at nuclear reactors.
Potential for Disasters: One possible disaster is a meltdown, where the fission reaction goes out of control, resulting in a nuclear explosion and the release of substantial amounts of radiation.
Cost: Nuclear energy generation is often very expensive.

Emissions: Nuclear power plants do not emit carbon dioxide, sulfur dioxide, or nitrogen oxides.
Nuclear Fuel Chain Emissions: However, fossil fuel emissions are associated with uranium mining, uranium enrichment, and transportation of uranium fuel to the nuclear plant.
Water Usage: Nuclear power plants consume large quantities of water for steam production and cooling, which can affect local aquatic life.
Water Pollution: Water pollutants, heavy metals, and salts found in the water used for power plant systems can degrade water quality and negatively impact aquatic wildlife.

Long-term Potential: If the Nuclear Energy Agency (NEA) estimates regarding accessible uranium are accurate, nuclear reactors could supply energy for the world at the current consumption rate for more than 100 years.
Resources: According to the NEA, identified uranium resources total 5.5 million metric tons, with an additional 10.5 million metric tons remaining undiscovered.