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Q32 (IAS/2011) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Atomic and nuclear physics Answer Verified

The Function of heavy water in a nuclear reactor is to

Result
Your answer: —  Â·  Correct: A
Explanation

In a nuclear reactor, heavy water (deuterium oxide or D2O) primarily functions as a neutron moderator. Its critical role is to slow down the high-speed (fast) neutrons produced during the fission reaction [1]. Slowing these neutrons is essential because thermal (slower) neutrons are significantly more effective at inducing further fission in uranium-235 nuclei, thereby sustaining a controlled chain reaction [2]. Heavy water is an exceptionally efficient moderator due to its high moderating ratio and low neutron absorption cross-section, which allows the reactor to maintain a high neutron economy and even utilize natural uranium as fuel [1]. While heavy water also serves as a primary coolant to transport heat away from the reactor core in certain designs like the CANDU or PHWR, its defining nuclear function remains the moderation of neutron velocity [1].

Sources

  1. [1] https://hwb.gov.in/frequently-asked-questions-faqs
  2. [2] https://en.wikipedia.org/wiki/Heavy-water_reactor
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SIMILAR QUESTIONS

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