Q1-5: These questions are about the processes occuring in a typical nuclear fission reactor:

1.Which of the following answers best describes the process of nuclear fission in a nuclear reactor?

• A. The splitting of heavy nuclei into smaller nuclei, requiring energy
• B. The splitting of heavy nuclei into smaller nuclei, releasing energy
• C. The joining together of smaller nuclei into heavier nuclei, requiring energy
• D. The joining together of smaller nuclei into heavier nuclei, releasing energy

2. Which isotope of uranium is the fissile material in the fuel rods in a typical nuclear reactor?

• A. Uranium - 238
• B. Uranium - 237
• C. Uranium - 236
• D. Uranium - 235

• A. photons
• B. protons
• C. neutrons
• D. electrons

4. The end products of a uranium nucleus fission reaction are 2 or 3 more particles, and 2  daughter nuclei X and Y. The original uranium nucleus will have ...

• A. a higher binding energy per nucleon than X and Y
• B. the same binding energy per nucleon as X and Y
• C. a lower binding energy per nucleon than X and Y
• D. a higher or lower binding energy per nucleon than X and Y

5. In the first stage of a chain reaction, the uranium nuclei is hit by one particle, releasing on average 2.5 more particles. These go on to hit additional uranium nuclei causing more fission to occur.

To the nearest particle, how many on average are released after the 4th stage of a fission chain reaction, assuming all particles strike a uranium nucleus?

• A. 10
• B. 36
• C. 39
• D. 81

6. This is a diagram of a nuclear reactor. When the top green rods are lifted as shown, the reaction rate increases.

What is the name given to these rods and what do they do?

7. Around the control rods and fuel rods is a moderator material. This is required to...

• A. absorb excess neutrons
• B. prevent radioactive daughter nuclei from damping the reaction
• C. lower the kinetic energy of neutrons
• D. lower the kinetic energy of the daughter nuclei

8. Which of the following statements describes the daughter nuclei by-products of a fission reaction?

• A. Radioactive and some have long half lives so difficult to store and dispose
• B. Radioactive but with short half lives so easy to store then dispose
• C. Not radiaoactive, but very high kinetic energy causing long term storage problems
• D. Not radioactive, and safe to store and dispose

Q9+10: These questions are about calculating the energy released during a fission reaction.

Isotope P is hit by a particle X, and splits into isotope Q and R, releasing 2 more X particles in the process.

P + X → Q + R + 2X

The following data describes these nuclei:

9. Approximately how much energy is released in the above fission reaction for a single nuclei of P?

• A. -200 MeV
• B. +200 MeV
• C. -1 MeV
• D. +1 MeV

10. Which of the following best describes the changes in mass defect and binding energy after the reaction?