Molten sodium is used in nuclear reactors to

Options

A. Absorb neutrons in order to control the chain reaction
B. Slow down the fast neutrons
C. Absorbs the heat generated by nuclear fission
D. Extract radio-isotopes produced in the reactor

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Role of Coolants in Nuclear Reactors:**
- In nuclear reactors, coolants are essential for transferring heat away from the reactor core. This heat is generated from the nuclear fission process.

2. **Properties of Sodium:**
- Sodium is a metal that has excellent thermal conductivity, meaning it can absorb and transfer heat very effectively. This property makes it suitable for use as a coolant.

3. **Molten State of Sodium:**
- Sodium is used in its molten state in nuclear reactors. When sodium is heated, it melts and becomes a liquid, which enhances its ability to flow and transfer heat efficiently.

4. **Absorption of Neutrons:**
- One of the critical functions of sodium in a nuclear reactor is its ability to absorb neutrons. This property helps in controlling the chain reaction that occurs during nuclear fission. By absorbing excess neutrons, sodium helps maintain a stable reaction rate.

5. **Heat Transfer:**
- As a coolant, molten sodium absorbs the heat generated from the fission process. This heat is then transferred away from the reactor core to produce steam, which can be used to drive turbines for electricity generation.

6. **Conclusion:**
- Therefore, molten sodium is used in nuclear reactors primarily because it serves as an effective coolant that can absorb heat and neutrons, helping to control the nuclear reaction and maintain safe operating temperatures.

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