Heavy water is used as a coolant in nuclear reactors because heavy water is:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Water containing heavy isotopes of hydrogen
Heavy water (D2O) is water in which the ordinary hydrogen atoms are replaced by deuterium, the heavy isotope of hydrogen with one proton and one neutron in its nucleus. It is about 11% denser than ordinary water.
In a nuclear reactor, heavy water slows down the fast neutrons released in fission while absorbing very few of them, so the chain reaction can go on with natural uranium. In India’s pressurised heavy water reactors it also carries the heat away from the fuel as the coolant.