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Deuterium oxide is used in nuclear reactors as
Fuel
Moderator
Shield
Regulator
Moderator
Deuterium oxide (D2тАЛO), commonly known as heavy water, is used as a moderator in nuclear reactors to slow down high-energy fast neutrons to thermal energies ┬╖ This process increases the probability of these neutrons inducing fission in fissile isotopes like 235U.
Deuterium oxide (D2тАЛO), commonly known as heavy water, is used as a moderator in nuclear reactors to slow down high-energy fast neutrons to thermal energies ┬╖ This process increases the probability of these neutrons inducing fission in fissile isotopes like 235U.
EkтАЛ=21тАЛmv2 тАФ kinetic energy of a neutron
╧ГsтАЛ тАФ scattering cross-section (which is high for D2тАЛO)
In a fission reaction, neutrons are released at high velocities ┬╖ A moderator consists of nuclei with low mass numbers that absorb kinetic energy from neutrons through elastic collisions ┬╖ Since the mass of the deuterium nucleus is close to that of a neutron, D2тАЛO is highly effective at moderating neutrons while having a very low neutron capture cross-section.
Heavy water (D2тАЛO) has an extremely low absorption cross-section for thermal neutrons.
It allows the use of natural uranium as fuel because of its efficiency as a moderator.
Used extensively in CANDU (Canada Deuterium Uranium) reactors.
Allows usage of natural uranium (non-enriched fuel).
High moderating ratio.
Excellent thermal properties for heat transfer.
High production cost of heavy water.
Requires high isotopic purity.
Research reactors.
Power production in CANDU-type nuclear plants.
Heavy water is chemically similar to ordinary water (H2тАЛO) but contains the isotope deuterium (2H).
Option A (Fuel) is incorrect; fuels are typically U235, Pu239, etc.
Option C (Shield) usually refers to concrete or lead structures used for biological protection against radiation.
Option D (Regulator) is a generic term not specifically used to describe a moderator's function.
B is correct тАФ Deuterium oxide serves as an efficient moderator by thermalizing fast neutrons through elastic scattering collisions.
Remember that a good moderator must have a low atomic mass to effectively transfer energy and a low probability of neutron capture to ensure chain reaction sustainability.