Radioactive materials randomly emit ionizing radiation all the time.
- Alpha radiation- An alpha particle is a slow moving helium nucleus (this does not mean it is a helium atom!!!). It has a positive charge. In alpha radiation the proton neutron decreses by 2 and the neutron number decreases by 2.
- Beta radiation- A beta particle is a fast moving electron. It has a negative charge. In beta radiation the proton number increases by 1 and the neutron number decreases by 1.
Contamination is where the radioactive substance is on your skin.
Irradiation is where the radioactive substance enters your body.
Ionizing radiation damages cells because it splits atoms into 2 smaller atoms.
Atoms have an outer cell of electrons and a nucleus which is made of protons and neutrons.
atoms and radioactivity
All atoms of any element have the same number of protons but can have different numbers of neutrons.
The activity of radioactive sources decreases with time.
Radioactive elements have a wide range of half life values.
There are three catagories of radioactive waste, each with different methods of disposal:
- Low level waste- includes labratory clothing and packaging materials, this is disposed of by being buried underground (landfill) or under the sea.
- Intermediate level waste- includes the casing used for nuclear fuel and reactor parts that have been replaced, these are kept in stores with thich concrete walls or buried in deep trenches with concrete linings.
- High level waste- includes used fuel rods, most of this waste is in temporary storage until how to dispose of it is decided.
radioactive waste and nuclear power stations
High level radioactive waste takes thousands of years to reach it's half life.
Electricity is a secondary energy source because the energy first has to be produced to make this which then powers things.
Renewable energy sources include:
Burning carbon fuels in power stations produces carbon dioxide.
Nuclear fission is where an atom is split into 2, neutrons go flying out and these break other atoms into 2, when this happens it is a chain reaction.
Nuclear power stations
Nuclear power stations work through nuclear fission, the energy from this creates heat and this heat, heats up water which then produces steam which then spins turbines, the turbines turn a generator which produces electricity.