Which is the coolant in fast breeder reactor

Options

A. Pressurised light water
B. boiling light water
C. deuterium or heavy water
D. liquid sodium

Answer

**Step-by-Step Solution:**

1. **Understanding Fast Breeder Reactors**: Fast breeder reactors are a type of nuclear reactor that generates more fissile material than it consumes. They are designed to use fast neutrons to convert fertile material into fissile material.

2. **Identifying Coolants**: In nuclear reactors, coolants are essential for transferring heat away from the reactor core to prevent overheating. The choice of coolant can significantly affect the reactor's efficiency and safety.

3. **Analyzing the Options**: The question provides four options for the coolant used in fast breeder reactors:
- Pressurized light water
- Boiling light water
- Deuterium or heavy water
- Liquid sodium

4. **Evaluating Each Option**:
- **Pressurized Light Water**: This is typically used in thermal reactors, not fast breeder reactors. Therefore, this option is incorrect.
- **Boiling Light Water**: Similar to pressurized light water, boiling light water is not suitable for fast breeder reactors. This option is also incorrect.
- **Deuterium or Heavy Water**: While heavy water can be used in some reactors, it is not the primary coolant for fast breeder reactors. This option is incorrect.
- **Liquid Sodium**: This is the most commonly used coolant in fast breeder reactors due to its excellent heat transfer properties and abundance. This option is correct.

5. **Conclusion**: Based on the analysis, the coolant used in fast breeder reactors is **liquid sodium**.

**Final Answer**: The coolant in fast breeder reactors is **liquid sodium**.

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