Presentation on theme: "Revision for P3: Radioactive Materials Tuesday, 14 April 2015 Learning Objective: To review the key areas in preparation for the P3 Exam."— Presentation transcript:
Revision for P3: Radioactive Materials Tuesday, 14 April 2015 Learning Objective: To review the key areas in preparation for the P3 Exam.
Nuclear Radiation Comes from the nucleus Nucleus contains neutrons and protons Electrons orbit around the edge Nucleus Electrons Two isotopes of Carbon – both have 6 protons but different numbers of neutrons.
3 Types of Radiation Alpha Very ionising Not very penetrating Absorbed by paper or dead skin cells Stopped by only a few centimetres of air Beta Slightly ionising Absorbed by aluminium or half a metre of air Gamma Not very ionising Very penetrating Absorbed by lead or thick concrete
Efficiency Efficiency, as a percentage, is worked out by: The more efficient the object is the less energy is wasted or dissipated in an wasteful way Be able to interpret energy flow diagrams Useful energy out x100 Total energy in
Background Radiation The dose of radiation is measured in sieverts Sv, or millisieverts mSv.
ContaminationIrradiation This is when the source is inside the body, or on your skin and will affect you all of the time. This is when a source outside the body affects you – but only when you are near it.
What happens when radiation hits a cell? Radiation passes straight through If it hits a sex cell it could cause a mutation by changing a gene Damaged – but repairs itself The DNA is damaged and the cell develops out of control – a cancer has begun It is killed
Energy Resources Primary Energy Source: A source of energy not made from any other sort of energy source e.g. fossil fuels and uranium Secondary Energy Source: A source of energy that can be distributed easily but has been manufactured using a primary energy source e.g. electricity
Renewable:Non-Renewable: Will not run out e.g. wind, solar, tides… Fossil Fuels – will run out; release waste including carbon dioxide; e.g. coal, oil, gas Nuclear Fuels – There are large amounts but not infinite, they release radioactive waste which has to be handled carefully; e.g. Uranium
Fossil Fuel Power Station Be able to label a diagram like this
Nuclear Power Station Know the differences between these 2 diagrams
Chain Reaction Uncontrolled – causes a nuclear bomb Controlled – used in a power station
Half Life The half life of a radioactive substance is the amount of time it takes for the activity (amount of radiation that is given out) to fall to half the previous value.
3 Types of Waste Low Level e.g. protective clothing and medical equipment Packed in drums and put in a special landfill site Intermediate Level Less dangerous that high level waste High Level E.g. spent/old fuel rods This gets hot as it is so radioactive, it’s kept in a pool of water to absorb the heat
Health and Radioactive Materials Some questions will expect you to understand and / or discuss: ALARA Risks and Benefit Precautionary Principle Perceived risk and Actual risk