A Level Nuclear

The nuclear fuel, which provides the power output in a nuclear reactor, decreases in mass at a rate of 6.0 × 10⁻⁶ kg per hour. What is the maximum possible power output of the reactor?

• 42 kW

• 75 MW

• 150 MW

• 300 MW

The mass of the nuclear fuel in a nuclear reactor decreases at a rate of 1.2 × 10⁻⁵ kg per hour.

Assuming 100% efficiency in the reactor what is the power output of the reactor?

• 100 MW

• 150 MW

• 200 MW

• 300 MW

Why is a moderator required in a thermal nuclear reactor?

• to prevent overheating of the nuclear core

• to absorb surplus uranium nuclei

• to shield the surroundings from gamma radiation

• to reduce the kinetic energy of fission neutrons

• A

• B

• C

• D

The moderator in a nuclear reactor is sometimes made of graphite. What is the purpose of the graphite?

• to absorb all the heat produced

• to decrease the neutron speeds

• to absorb the α and γ radiations

• to prevent the reactor from going critical

Nobelium-259 has a half-life of 3500 s.

What is the decay constant of nobelium-259?

• 8.7 × 10^–5 s^–1

• 2.0 × 10^–4 s^–1

• 1.7 × 10^–2 s^–1

• 1.2 × 10^–2 s^–1

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

• Boron

• Concrete

• Uranium-238

• Water

• A

• B

• C

• D

Which one of the following statements is not true about the control rods used in a nuclear reactor?

• They must absorb neutrons.

• They must slow down neutrons to thermal speeds.

• They must retain their shape at high temperatures.

• The length of rod in the reactor must be variable.

• A

• B

• C

• D