Electrical Engineering XYZ MCQs

Which of the following statements are true in reference to nuclear plants:

- In nuclear reactor, multiplication factor is kept almost equal to one
- A thermal reactor needs a moderator material
- Both of the above
- Nuclear power plants are used as peak load plants only

Correct answer: 3. Both of the above

Explanation:

- “In nuclear reactor, multiplication factor is kept almost equal to one” – This statement is correct. In a nuclear reactor, particularly in steady-state operation, the goal is often to maintain the multiplication factor (k) close to one. When the multiplication factor is 1.0, it indicates a critical condition where the number of neutrons produced in each fission event is balanced by the number of neutrons lost through absorption or leakage, leading to a stable nuclear chain reaction. Therefore, this statement is true.
- “A thermal reactor needs a moderator material” – This statement is also true. In a thermal reactor, such as most commercial nuclear power reactors, a moderator material is required to slow down fast neutrons produced by fission reactions. Slowing down these neutrons increases the probability of further fission events, sustaining the chain reaction. Common moderator materials include water, graphite, and heavy water. Therefore, this statement is also true.