Question

Statement (I): A breeder reactor does not require moderator.

Statement (II): The parasite absorption of neutrons is low.
1. Both statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
2. Both Statement (I) and Statement (II) are individually true but statement (II) is not the correct explanation of Statement (I)
3. Statement (I) is true but Statement (II) is false
4. Statement (I) is false but Statement (II) is true

Answer 1

Correct Answer - Option 1 : Both statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Explanation:

• The plutonium-239 breeder reactor is commonly called a fast breeder reactor, and the cooling and heat transfer is done by a liquid metal.
• The metals which can accomplish this are sodium and lithium, with sodium being the most abundant and most commonly used.
• The reactor fuel is surrounded by a "blanket" of non-fissionable U-238. No moderator is used in the breeder reactor since fast neutrons are more efficient in transmuting U-238 to Pu-239.
• At this concentration of U-235, the cross-section for fission with fast neutrons is sufficient to sustain the chain-reaction.