0
What are the functions of the moderator and the control rods in a fission reactor?
Wiki User
∙ 11y ago
Moderator: slows fast fission neutrons (several MeV energy) to slow "thermal" neutrons ( <5eV energy), making it less likely for Uranium-238 to capture them and more likely for them to cause fission of Uranium-235. Breeder reactors don't use moderator.
Control rods: absorb excess neutrons to allow the operating reactor to be kept EXACTLY critical and under control. They are equivalent to the accelerator & brake in a car.
SCRAM rods: absorb neutrons for emergency shutdown. They are equivalent to emergency brake in a car.
Did I answer more than you asked?
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
How is the rate of the fission in a nuclear reactor controlled?
By the control rods and by the moderator.
What are the fuctions of moderator and controller in nuclear reactor?
moderator, slows fast fission neutrons to thermal (near room temperature) energies rapidly enough to prevent their capture by uranium-238 before they can participate in the chain reaction and fission uranium-235control, remove excess neutrons so as to hold the reactor at exactly critical at all times, permit control of increases and decreases of operating power level
Primary function of moderator in nuclear reactor?
What is the primary function of a Moderator in a nuclear reactor
What is the cooling water for in a nuclear reactor?
The primary purpose of the cooling water in a reactor is obvious, cool the reactor core by carrying heat away to someplace else. That someplace else is usually a heat exchanger/steam generator, which generates steam to turn the turbine generators that make electricity. In light water moderated reactors, the cooling water also serves a secondary purpose as the moderator. The moderator is a material that slows the fast neutrons from the fission to slow thermal neutrons before too many are absorbed by the plentiful Uranium-238 isotope, which will not fission. These thermal neutrons then fission the rare Uranium-235 isotope to keep the reactor going.
What is in the core of a nuclear reactor?
The core of the nuclear reactor includes:nuclear fuel elements (composed of the fuel meat covered with cladding)reactor coolantreactor moderator (for thermal reactors)control elementsmeasuring instrumentsstructural and support structures
How is the rate of the fission in a nuclear reactor controlled?
By the control rods and by the moderator.
What are the basic feartures of a fission reactor?
The fission reactor is composed of:Nuclear fuel,reactor coolants,neutron moderator (optional)control elementsshieldingmeasurement instrumentssupporting structures... etc
Which are needed in fission reactor?
nuclear fuelcoolantneutron moderator (if needed)control elementsshieldingmeasurement instrumentationemergency systemssupport structures
In nuclear reactor heavy water is used as?
Heavy water (deuterium) functions as a moderator. It slows down fast neutrons released by fission reactions in order to allow the reaction to be sustained. Fast neutrons pass through the reactor before initiating another fission reaction.
What are the functions of a nuclear reactor components?
Mainly:Nuclear fuel: where nuclear fission and energy is producedReactor coolant: to extract heat from fuelReactor neutron moderator: to reduce neutron energy to thermal range (0.025 ev)Reactor control elements: to control nuclear reaction rate, compensate for fuel burnup, and for shutdown and safety conditionsReflector: to reduce neutron leakage
Do moderator in nuclear reactor slows down the neutrons emitted during fission?
Yes, it is the main moderator function in what is called "thermal nuclear reactors"
What is the function of a control rods reactor?
Control rods are used in a reactor to control the rate at which fission happens.
Two important functions of heavy water in a candu reactor?
moderator, coolant
Why moderator is not used in case of fast breeder reactor?
Moderator is not used in case of fast breeder reactor because there is no need to slow down neutron energy. Nuclear fission takes place at high energy of neutrons.
What is possibly happen to neutrons produce in a fission reactor?
The neutrons produced by fission in a nuclear fission reactor during the process of thermalization to be available for a new generation of fission could be subject to:absorption in fuelabsorption in non fuel reactor components (moderator, clad, structural material, ...)fast leakageresonance capture in U-238fast fission in U-238thermal leakage
What are the fuctions of moderator and controller in nuclear reactor?
moderator, slows fast fission neutrons to thermal (near room temperature) energies rapidly enough to prevent their capture by uranium-238 before they can participate in the chain reaction and fission uranium-235control, remove excess neutrons so as to hold the reactor at exactly critical at all times, permit control of increases and decreases of operating power level
What is the difference between a neutron shield and a neutron moderator?
Shielding is used to prevent the escape of neutrons from a reactor. A moderator is used in the reactor to undergo collisions with a neutron. The neutrons produced in fission collide with the molecules of the moderator, imparting their kinetic energy on them. This generates heat in the reactor. (Temperature is the measure of the average random molecular kinetic energy of a substance).
