8463/1H June 2020

Coach Name: Sir Muhammad Abdullah Shah

6.​​ Radioactive waste from nuclear power stations is box a man-made source of background radiation.

i-​​ Give one other man-made source of background radiation.​​ 

[1 mark]

ANSWER

  • Medical​​ X-rays & CT Scan

  • Testing of nuclear weapons

(You may choose any two points from above.)

Nuclear power stations use the energy released by nuclear fission to generate electricity.​​ 

ii-​​ Give the name of one nuclear fuel.​​ 

[1 mark]

ANSWER

  • Uranium​​ 

  • Plutonium

(You may choose any two points from above.)

iii-​​ Nuclear fission releases energy.​​ 

Describe the process of nuclear fission inside a nuclear reactor.​​ 

[4 marks]

ANSWER

Neutron is fired at Uranium nucleus which splits the nucleus into lighter nuclei and 2 or​​ 3 energetic electrons are released. Moreover,​​ energy is emitted in the form of gamma rays.​​ 

iv-​​ A new type of power station is being developed that will generate electricity using nuclear fusion.

Explain how the process of nuclear fusion leads to the​​ release of energy.​​ 

[2 marks]

ANSWER

Fusion is when lighter smaller nuclei are fused together to make a larger nucleus releasing energy. This energy comes from the conversion of mass difference.

v-​​ Nuclear fusion power stations will produce radioactive waste. This waste will have a much shorter half-life than the radioactive waste from a nuclear fission power station.

Explain the advantage of the radioactive waste having a shorter half-life.

[2 marks]

ANSWER

  • The activity of the waste decreases quickly.​​ 

  • There is less risk of harm.​​ 

  • Disposing or burial sites don’t need to be monitored for a long perid of time.​​