P4 - Nuclear Fission*

Question 1

What happens in Nuclear fusion?

Answer 1

Two light nuclei combine to create a larger nucleus .

Question 2

What is one example of nuclear fission?

Answer 2

• Two atoms of different hydrogen isotopes combining to form helium.

Question 3

What are some advantages of Nuclear fusion over Nuclear fission?

Answer 3

• Fusion doesn’t leave behind much radioactive waste.
• There is plenty of hydrogen in the air to use as a fuel source
• Fusion releases a lot of energy, more than fission for a given mass.

Question 4

What are some issues with fusion?

Answer 4

• Fusion only happens at really high pressures and temperatures ( 10,000,000 degrees celsius ).
• No material can physically withstand that kind of temperature and pressure, so reactors are really hard to build.
• It is hard to safely control the high temperatures and pressures.

Question 5

Why is it currently inefficient to use fusion for generating power?

Answer 5

• The amount of energy required to get up to temperature is greater than what the reactor produces.

Question 6

Why is research into fusion power carried out by international groups?

Answer 6

It carried out by international groups to share the costs, expertise and experience and the benefits.

Question 7

How do fusion bombs work?

Answer 7

• Fusion reactions happen in fusion bombs.
• They are often referred to as hydrogen bombs or H bombs.
• In fusion bombs, a fission reaction is used first to create the really high temperatures needed for fusion.

Question 8

What must happen to scientific theories before they are accepted?

Answer 8

Scientific theories must go through validation before they are accepted.

Question 9

What is cold fusion?

Answer 9

Cold is nuclear fusion which occurs at around room temperature, rather than at millions of degrees celsius.

Question 10

Why is cold fusion not accepted?

Answer 10

• Two scientists had reported that they had succeeded in releasing energy from cold fusion, using a simple experiment.
• This caused a lot of excitement, cold fusion would make it possible to generate lots of electricity easily and cheaply.
• After the press conference, the experiments and data were shared with other scientists so they could repeat the experiments, but few managed to reproduce the results reliably ,so it hasn’t been accepted as a realistic method of energy production.