Heavy water is used in atomic reactor as

Options

A. coolant
B. moderator
C. both coolant and moderator
D. neither coolant nor moderator

Answer

**Step-by-Step Solution:**

1. **Understanding the Context of Heavy Water:**
- Heavy water, chemically represented as D₂O, is an isotope of water where the hydrogen atoms are replaced by deuterium, a heavier isotope of hydrogen.

2. **Role of Heavy Water in Nuclear Reactors:**
- In the context of nuclear reactors, heavy water serves two primary functions: as a coolant and as a moderator.

3. **Function as a Coolant:**
- As a coolant, heavy water helps in the removal of heat generated during the nuclear fission process. This is crucial to prevent overheating of the reactor components and to maintain safe operating temperatures.

4. **Function as a Moderator:**
- As a moderator, heavy water slows down the fast neutrons produced during fission. Slower neutrons are more likely to induce further fission reactions when they collide with fissile material, thus sustaining the nuclear chain reaction.

5. **Conclusion:**
- Therefore, heavy water is used in atomic reactors primarily as both a coolant and a moderator.

**Final Answer:**
Heavy water is used in atomic reactors as a coolant and a moderator.

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