Friday, 21 June 2013

NUCLEAR POWER/ENERGY

What is Nuclear Energy? What is Nuclear Power?

NUCLEAR  ENERGY

Energy from splitting Uranium atoms

Nuclear Power Energy is generated using Uranium, which is a metal mined in various parts of the world.
The first large-scale nuclear power station opened at Calder Hall in Cumbria, England, in 1956.
Some military ships and submarines have nuclear power plants for engines.
Nuclear power produces around 11% of the world's energy needs, and produces huge amounts of energy from small amounts of fuel, without the pollution that you'd get from burning fossil fuels.

 How Does Nuclear Energy Works/ How Nuclear Energy Power Produced

Nuclear Power Plant Works

How Does Nuclear Energy Works/ How Nuclear Energy Power Produced

Nuclear power stations work in pretty much the same way as fossil fuel-burning stations, except that a "chain reaction" inside a nuclear reactor makes the heat instead.

The reactor uses Uranium rods as fuel, and the heat is generated by nuclear fission: neutrons smash into the nucleus of the uranium atoms, which split roughly in half and release energy in the form of heat.Carbon dioxide gas or water is pumped through the reactor to take the heat away, this then heats water to make steam.

The steam drives turbines which drive generators
Modern nuclear power stations use the same type of turbines and generators as conventional power stations.
In Britain, nuclear power stations are often built on the coast, and use sea water for cooling the steam ready to be pumped round again. This means that they don't have the huge "cooling towers" seen at other power stations.

The reactor is controlled with "control rods", made of boron, which absorb neutrons. When the rods are lowered into the reactor, they absorb more neutrons and the fission process slows down. To generate more power, the rods are raised and more neutrons can crash into uranium atoms.
Natural uranium is only 0.7% "uranium-235", which is the type of uranium that undergoes fission in this type of reactor.

The rest is U-238, which just sits there getting in the way. Modern reactors use "enriched" uranium fuel, which has a higher proportion of U-235.

The fuel arrives encased in metal tubes, which are lowered into the reactor whilst it's running, using a special crane sealed onto the top of the reactor.

With an AGR or Magnox station, carbon dioxide gas is blown through the reactor to carry the heat away. Carbon dioxide is chosen because it is a very good coolant, able to carry a great deal of heat energy. It also helps to reduce any fire risk in the reactor (it's around 600 degrees Celsius in there) and it doesn't turn into anything nasty (well, nothing long-lived and nasty) when it's bombarded with neutrons.You have to be very careful about the materials you use to build reactors - some materials will turn into horrible things in that environment. If a piece of metal in the reactor pressure vessel turns brittle and snaps, you're probably in trouble - once the reactor has been built and started you can't go in there to fix anything..

Uranium itself isn't particularly radioactive, so when the fuel rods arrive at the power station they can be handled using thin plastic gloves. A rod can last for several years before it needs replacing.
It's when the "spent" fuel rods are taken out of the reactor that you need the full remote-control robot arms and Homer Simpson equipment.

Advantages Of Nuclear Power/ Energy

1. The amount of electricity produced in a nuclear power station is equivalent to that produced by a fossil fuelled power station.
2. Nuclear power stations do not burn fossil fuels to produce electricity and consequently they do not produce damaging, polluting gases.
3. Many supporters of nuclear power production say that this type of power is environmentally friendly and clean. In a world that faces global warming they suggest that increasing the use of nuclear power is the only way of protecting the environment and preventing catastrophic climate change.
4. Many developed countries such as the USA and the UK no longer want to rely on oil and gas imported from the Middle East, a politically unstable part of the world.
5. Countries such as France produce approximately 90 percent of their electricity from nuclear power and lead the world in nuclear power generating technology - proving that nuclear power is an economic alternative to fossil fuel power stations.
6. Nuclear reactors can be manufactured small enough to power ships and submarines. If this was extended beyond military vessels, the number of oil burning vessels would be reduced and consequently pollution.

Disadvantages OF Nuclear Power/ Energy

1. Nuclear power is a controversial method of producing electricity. Many people and environmental organisations are very concerned about the radioactive fuel it needs.
2. There have been serious accidents with a small number of nuclear power stations. The accident at Chernobyl (Ukraine) in 1986, led to 30 people being killed and over 100,000 people being evacuated. In the preceding years another 200,00 people were resettled away from the radioactive area. Radiation was even detected over a thousand miles away in the UK as a result of the Chernobyl accident. It has been suggested that over time 2500 people died as a result of the accident.
3. There are serious questions to be answered regarding the storage of radioactive waste produced through the use of nuclear power. Some of the waste remains radioactive (dangerous) for thousands of years and is currently stored in places such as deep caves and mines.
4. Storing and monitoring the radioactive waste material for thousands of years has a high cost.
5. Nuclear powered ships and submarines pose a danger to marine life and the environment. Old vessels can leak radiation if they are not maintained properly or if they are dismantled carelessly at the end of their working lives.
6. Many people living near to nuclear power stations or waste storage depots are concerned about nuclear accidents and radioactive leaks. Some fear that living in these areas can damage their health, especially the health of young children.
7. Many Governments fear that unstable countries that develop nuclear power may also develop nuclear weapons and even use them.

No comments:

Post a Comment