1. Learning Objective:
•To review the key areas in
preparation for the P6 Exam.
Revision for
P6: Radioactive Materials

2. Nuclear Radiation
• Comes from the nucleus
• Nucleus contains neutrons and protons
• Electrons orbit around the edge
Electrons
Nucleus
Two isotopes of Carbon – both have 6 protons but different
numbers of neutrons.

3. 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

4. Efficiency
• Efficiency, as a percentage, is worked out by:
Useful energy out
x100
Total energy in
• The more efficient the object is the less energy is
wasted or dissipated in an wasteful way
• Be able to interpret energy flow diagrams

5. Background Radiation
The dose of
radiation is
measured in
sieverts Sv,
or
millisieverts
mSv.

6. Contamination Irradiation
This is when the source This is when a source
is inside the body, or on outside the body affects
your skin and will affect you – but only when you
you all of the time. are near it.

7. Damaged – but
Radiation repairs itself
passes straight
through
What happens when
radiation hits a cell?
If it hits a sex
It is killed
cell it could
cause a
mutation by The DNA is damaged and
changing a the cell develops out of
gene control – a cancer has
begun

8. Energy Resources
Primary Energy Secondary Energy
Source: Source:
• A source of energy • A source of energy
not made from any that can be distributed
other sort of energy easily but has been
source manufactured using a
• e.g. fossil fuels and primary energy
uranium source
• e.g. electricity

9. Renewable: Non-Renewable:
Will not run out Fossil Fuels – will run
e.g. wind, solar, tides… 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

10. Fossil Fuel Power Station
Be able to label a diagram like this

11. Nuclear Power Station
Know the differences between these 2 diagrams

12. Fission
Neutron

13. Chain Reaction
Uncontrolled – causes a
nuclear bomb
Controlled – used in a
power station

14. 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.

15. 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

16. 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