Using radioactive materials Flashcards
What can ionising radiation do to living cells?
It can damage living cells and these may be killed or become cancerous
What positive uses are there of ionising radiation?
Treating cancer, sterilising surgical instruments, sterilising food, as a tracer in the body
What are the main sources of background radiation?
Cosmic rays,
Rocks and soil,
Living things
How can we protect and monitor radiation that affects radiographers?
Regular checks for their level of exposure,
A film badge, gets blacker with the more radiation present,
Lead shielding as aprons or protective walls
Where is the energy in nuclear fuel released from?
It is released by changes in the nucleus
What happens in nuclear fission?
A neutron splits a large and unstable nucleus (uranium and plutonium) into two smaller parts, roughly equal in size, releasing more neutrons and energy
How does the energy produced in nuclear fission compare to that produced by a similar mass of fossil fuels?
The energy produced by a tiny mass of materials in fission is massively greater than the amount produced by large amounts of fossil fuels, let alone the same mass
What would happen if nuclear fission was not controlled?
Without control nuclear fission would be an exponential process as for each neutron that splits a large nuclei, three more neutrons are produced which then fission react, each creating three more neutrons.
How are fission reactions controlled?
To control the exponential increase in neutrons produced in fission reactions, control rods are put in between reactions that absorb these neutrons as they are created and the reactions can then be limited.
What are three types of nuclear waste?
Low-level waste, intermediate-level waste, high-level waste
What are examples of low level waste and how is it disposed of?
Contaminated paper and clothing.
It is not dangerous to handle but should be disposed with care: burnt and sealed in containers buried in landfill
What are examples of intermediate level waste and how is it disposed of?
Chemical sludges, reactor parts.
More radioactive and needs shielding: waste with a longer half-life is buried underground.
What are examples of high level waste and how is it disposed of?
Spent fuel rods.
Highly radioactive: some is mixed with molten glass and contained in stainless steel drums before careful storage
