Nuclear Processes

Nuclear Energy

Charles Cao

What is nuclear energy? What are some pros and cons of nuclear power plants?

Nuclear energy involves splitting or combining atoms to produce useful energy. Nuclear energy doesn’t make carbon dioxide, so nuclear power is a potential global solution to climate change. And nuclear energy is dependable and sustainable, so it is a strong candidate for supplying our energy while alleviating these struggles of consumption of energy. But radiation is harmful, a nuclear power plant leak would threaten the safety of organisms around it. Thus, nuclear energy is still among the least popular forms of energy.

Define fusion and fission. Compare and contrast them. What are some pros and cons of fission?

There are two nuclear processes: fission and fusion. Nuclear fission releases heat energy by splitting atoms. Nuclear fission takes place when a large, somewhat unstable isotope is bombarded by high-speed particles, usually neutrons. Neutrons in the majority of nuclear power reactors today is Uranium-235. This resulting energy is then used to heat water in nuclear reactors and ultimately produces electricity. Nuclear fusion refers to the union of atomic nuclei to form heavier nuclei resulting in the release of enormous amounts of energy. Atoms of tritium and deuterium unite under extreme pressure and temperature to produce a neutron and a helium isotope. An enormous amount of energy is released, which is several times the amount produced from fission. Scientists continue to work on controlling nuclear fusion in an effort to make a fusion reactor to produce electricity. However, it is difficult to control the reaction in a contained space. As a result, compared to fusion, fission's pros is easier control, cons is less produced energy.

Identify the parts of a nuclear reactor. Compare and contrast the similarities and differences between a Pressurized Water Reactor and a Boiling Water Reactor.

There are several components common to most types of reactor: fuel, moderator, control rods/blades, coolant, pressure vessel/tubes, steam generator, and containment. And there are two popular types of reactors: pressurised water reactor (PWR) and boiling water reactor (BWR). They have many similarities. For example, Both PWR and BWR employ nuclear fission reaction to generate thermal energy, which is utilized to drive the turbine for generating electricity. Both PWR and BWR require 3 – 5% enriched uranium fuel. Both PWR and BWR employ only normal water or light water as moderator, as coolant and also as working fluid. There are also some differences. For instance, PWR consists of two circuits, but BWR consists of only one circuit. Steam is generated in a heat exchanger outside PWR, but within BWR reactor itself. PWR has comparatively low thermal efficiency and BWR offers higher thermal efficiency.

What are three types of regulated nuclear waste? What do countries/states do with their nuclear waste?

There are three types of nuclear waste, classified according to their radioactivity: low-, intermediate-, and high-level. There are two main waste management strategies that exist across the world: recycling and direct disposal. Recycling is to subsequently mix separated plutonium and uranium with fresh uranium and made into new fuel rods. Countries such as France, Japan, Germany, Belgium and Russia have all used plutonium recycling to generate electricity, whilst also reducing the radiological footprint of their waste. Direct disposal is to place the used fuel in canisters which, in turn, are placed in tunnels and subsequently sealed with rocks and clay. The waste from recycling will also be placed in the repository. Repositories are nearing completion in for instance Finland.

Thank you!