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Nuclear Energy

By: Edward Tsui, NBJ, Miranda Tang, Sean Li

+Introduction

Concept of the possibility of absorbing energy from atoms came from the 30s

First uses of “Nuclear” energy is focused in military uses

Civil use of Nuclear Energy came popular in the 80s

Huge debate on whether to use nuclear power

Provides 12~13% of the world’s electricity currently

+World Usage of Nuclear Energy/ Energy as general

Nuclear Energy produces 75% of France’s electricity

By 2030 China is projected to be using almost as much oil as the USA does now

Consumption is now twice of the rate of discovery

Total energy demand is expected to double between 2002 and 2030 (From 16,000 billion kWh in 2002 to a projected number of 31,600 billion kWh)

+Concept of Nuclear Power

Through the process of fission

Mass energy is released by splitting large atoms to produce medium sized atoms

Usually Uranium U235 / Plutonium 239 are being used as nuclear fuel

A constant, clean (to be disputed) and scalable energy source

+Electricity Generation process

+Step 1 – Mining of Uranium Ore

+Step 2 – Enrichment/Purify

Uranium as mined cannot be fed directly into a power station.

Usually concentrated and made up to special fuel rods (metal bars)

Enrichment requires the uranium to be in the form of gas

Increases the proportion of U-235 from 0.7% to ~3.5% (Usually)

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+Step 3 – Fuel Fabrication

Enriched UF6 gas is converted to uranium dioxide (UO2), which is formed into ceramic fuel pellets by baking it at a high temperature (over 1400°C).

Pellets are encased in metal tubes

To be put in bundles as fuel in the Nuclear Reactor

+Step 4 – Reactor/ Electricity Production

+Step 4 – Reactor/ Electricity Production

Energy released from fission would be used to generate steam (basically boiling water)

Through the steam line the steam would be used to move the steam turbine then produce electricity through the generator

Exact same process as using coal

+Step 5 – Disposal/Waste

Usually nuclear fuel would be changed once per months

Nuclear waste could be disposed in secured storages (some underground)

Or it could be reprocessed and used again

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+Advantages of using nuclear power – Compared with coal

The only major fuel options for base-load energy production is either Coal or Nuclear Power

About 20,000 times as much coal is required in mass terms of electricity production

Coal will be used up in about 150 years, however more uranium resources are to be developed

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+Advantages of using nuclear power- Compared with coal

Waste produced from coal plants directly emits upon the atmosphere

Nuclear waste could be stored or to be reused

Transportation costs are very high for coal

Nuclear power plants could provide work for local industries which build the plant and also minimize long term commitments to buying fuels aboard

+Advantages of using nuclear power – Compared with renewable energy Some environmental movements launched the “blind

and anti-scientific opposition to this proposition” and “abandoned science and logic in favor of emotion and sensationalism”

To power the entire world with 50% wind energy, you would need about one percent of the world land

Nuclear energy’s greenhouse gas is even below solar power

+Advantages of using nuclear power- Compared with renewable energy Wind and Solar is simply a type of dilute, variable energy

Typically getting one gigawatt of wind power from 250 square miles and one gigawatt of solar power from 50 square miles

Basic arithmetic problem

There are not a fourth choice for base-load electricity ( Fossil fuels: 66.1%/ Hydro: 16.1%/ Nuclear: 15.7%)

+Advantages of using nuclear power- Compared with renewable energy Small and cheap nuclear reactors are being made for

developing countries

Could be used for purifying water

+Uranium Availability

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+The Megatons to Megawatts program

An important source of nuclear fuel is the world’s nuclear weapons stockpiles

Contain a great deal of uranium enriched to over 90% U-235 (about 25 times the proportion in most reactor fuel)

The 500 tonnes of weapons stockpiles of Russia is equivalent to about 153,000 tonnes of natural uranium, more than twice the annual world demand

+Megatons to Megawatts icon

+Nuclear Fusion

The opposite of Nuclear Fission – Combining multiple atomic particles to produce energy

The is what provides the sun and the stars with the energy to shine continuously for billions of years

+Disadvantages of nuclear energy:

Nuclear energy involves with large and dangerous amount of radiation

A single nuclear disaster could affect a large region of area

Accidents did occur in the history of nuclear energy, infamously, (Chernobyl 1986 / Three Mile Accident 1979/ Fukishima 2011)

+Disadvantages of nuclear energy

Countries, such as Iran and North Korea could be using civil nuclear power plants as a disguise to develop nuclear weapons

Trucks loaded with Nuclear-related materials and nuclear plants could be an attack target

+Conclusion – Energy Saving

Nuclear Energy should be used appropriately

Energy saving is the only solution to the problem

The first world behaves like an addicted smoker, distracted by short term benefits and ignorant of long-term risk

There would never be enough energy for the world to use

+Conclusion- Energy Saving

However a significant reduction seems unlikely

Uneven world distribution of energy resources