Moderator used in nuclear power plants: identify a common choice Which of the following is commonly used as a neutron moderator in power reactors? Choose the correct option.
Mechanical Engineering
IC Engines and Nuclear Power Plants
Difficulty: Easy
Choose an option
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AGraphite
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BHeavy water
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CConcrete
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DGraphite and concrete
Answer
Correct Answer: Heavy water
Explanation
ConceptA moderator slows down fast neutrons to thermal energies to sustain fission efficiently. Common moderators used in power reactors include heavy water (D2O) and graphite. Concrete is primarily a shielding material, not a moderator.
Why choose heavy water hereAmong the listed choices, both graphite (A) and heavy water (B) are valid moderators; with a single answer MCQ and typical power-plant emphasis (e.g., PHWRs), heavy water is the most fitting selection. Options involving concrete are incorrect as moderators.
Final AnswerHeavy water