Q57
The fast breeder reactor uses the following moderator
A.
Demineralised water
B.
Carbon dioxide
C.
Heavy water
D.
No moderator is used
AnswerAnswer: Option D
Solution
Answer: Option D
Solution:
No moderator is used in the breeder reactor since fast neutrons are more efficient in transmuting U238 to Pu239. At this concentration of U235, the cross-section for fission with fast neutrons is sufficient to sustain the chain-reaction.