Question 1

What is the main purpose of a moderator in a thermal nuclear reactor?


  A  

to shield the surroundings from ionising radiations


  B  

to decrease the number of fission chain reactions

  C  

to decrease neutron speeds


  D  

to prevent the core from overheating

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Question 2

In the core of a nuclear reactor, the mass of fuel decreases at a rate of 9.0 × 10−6 kg hour−1 due to nuclear reactions.

What is the maximum power output of the reactor?

  A  

2.3 × 108 W


  B  

1.4 × 1011 W

  C  

8.1 × 1011 W

  D  

2.9 × 1015 W

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Question 3

A deuterium nucleus and a tritium nucleus fuse together to form a helium nucleus and a particle X. The equation for this process is:

12H + 13H 24He + X

What is X?

  A  

electron

  B  

neutron

  C  

positron

  D  

proton

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Question 4

What effect are the control rods intended to have on the average kinetic energy and number of fission neutrons in a thermal nuclear reactor?


  A  
  B  
  C  
  D  

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Question 5

During a single fission event of uranium-235 in a nuclear reactor the total mass lost is 0.23 u. The reactor is 25% efficient.

How many events per second are required to generate 900 MW of power?

  A  

1.1 × 1014

  B  

6.6 × 1018


  C  

1.1 × 1020


  D  

4.4 × 1020


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Question 6

Which of the following substances can be used as a moderator in a nuclear reactor?


  A  

boron

  B  

concrete

  C  

uranium-238


  D  

water

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Question 7

The mass of the fuel in a fission reactor decreases at a rate of 6.0 × 10−6 kg hour−1.

What is the maximum possible power output of the reactor?

  A  

75 MW

  B  

150 MW

  C  

300 MW

  D  

9,000 MW

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Question 8

When a nucleus of uranium-238 absorbs a neutron, one combination of fission products can be tin-126 and a nucleus of element X. 13 neutrons are also emitted.

92238U + 01n X + 50126Sn + 1301n

How many neutrons are there in the nucleus of element X?

  A  

30

  B  

42

  C  

58

  D  

100

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Question 9

The total energy released in a single fusion reaction is 4.0 MeV.

What is the change in mass in this fusion reaction?

  A  

7.1 × 10−36 kg

  B  

7.1 × 10−30 kg

  C  

2.1 × 10−21 kg

  D  

4.4 × 10−17 kg

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