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How can the rate of reaction be slowed down in a nuclear fission reactor?
Wiki User
∙ 8y ago
By inserting the control rods which absorb neutrons using boron, cadmium, or other material with a large neutron capture crosssection.
If the reactor should begin to run out of control the SCRAM system will suddenly insert large amounts of neutron absorbing material, instantly stopping the neutron chain reaction.
Wiki User
∙ 8y ago
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What is a nuclear reactor?
An assembly of fissile fuel (U-235 or PU-239) arranged in a geometric array. The assembly can be made to go critical such that a chain reaction starts which builds up a neutron flux inside the assembly. The chain reaction is controlled at a steady level using neutron absorbing control rods.The nuclear reactor can classified under:a thermal nuclear reactor, where the majority of fissions are caused by slow neutrons. In these reactors, the fast neutrons produced by fissions are slowed down with a moderator which can be graphite, heavy water or light water, anda fast nuclear reactor where the majority of fissions are caused by fast neutrons
What type of energy is nuclear energy?
Nuclear energy is released in fission when a nucleus is split. A small proportion of the mass of the nucleus is annihilated and converted to free energy. Initially this appears as the kinetic energy of the fission fragments, this is quickly converted to thermal energy as the fragments are slowed down.
Why does an atomic bomb explode?
It explodes because it contains a critical mass of unstable atoms of a heavy metal such as Uranium-235 or Plutonium-239. When the nucleus of one of these large atoms is hit by a neutron, the atom splits into two medium-size atoms such as Barium and Krypton or Strontium and Xenon, and also releases 2 or more free neutrons and a burst of energy. This process is called Nuclear Fission. The free neutrons from one nuclear fission can then create more fissions, and a Chain Reaction is begun. More fissions release more neutrons which create more fissions which release even more neutrons, etc. If conditions are right, this chain reaction proceeds explosively to form a Nuclear Fission Bomb or "Atomic Bomb". If this chain reaction is slowed and controlled, then the nuclear fission produces heat energy which can be used to boil water in a Nuclear Power Plant. Rapid fission, nuclear bomb. Slow controlled fission, nuclear power plant.
What type of nuclear reaction is used n power plants?
Most nuclear power stations have pressurized water thermonuclear reactors. The nuclear reactions that take place in these reactors are fission (atom splitting) and nuclear decay. (Let's not split hairs so we can concentrate on splitting atoms.) In simple terms, these reactors work by fission of enriched uranium, which is uranium with a higher-than-natural amount of the U235 isotope. This isotope has a higher probability of capturing a neutron and splitting than other stuff. That's the fission part. After the uranium splits, neutrons are released and these can be used to make more fissions if they are slowed (thermalized). Links to Wikipedia are provided. There must be some consideration given to the fission products. These are the "broken pieces" left after an atom splits. There are a fair number of these and they continue to decay. Their half lives and decay schemes vary, and an interested party would review the Wikipedia article to get the low down on them. A link is provided.
Why must neutrons in a chain reaction be controlled?
Neutrons in a nuclear fission chain reaction must be controlled for two reasons... First, they must be moderated, or "slowed down", to exactly the right level of energy required to sustain the reaction. This is because, initially, the neutrons are too fast to sustain the fission reaction. They must be slowed down, but not too much, otherwise the reaction will stop. Second, they must be controlled. You want the reaction to proceed at an orderly pace, at a constant rate. To do this, you need, on a statistical average, exactly one neutron to go on to fission one atom to produce one parcel of binding energy release and one neutron, to repeat without multiplying or dividing. This is what we call KEffective = 1, where the rate of reaction does not change. Moderation and control. In tight balance. Easily upset. Fortunately, when upset, the tendency is to shutdown. That is engineering safety.
How can nuclear fission be slowed?
Yes, by introducing a neutron absorber such as boron. In a nuclear reactor this is done by inserting the control rods
How many neutrons are produced during a typical uranium fission reaction and what is the role of these neutrons in a nuclear chain reaction?
A typical uranium fission event produces 2 to 3 neutrons. These neutrons are moderated (slowed down) and go on to initiate the fission of more uranium. On average, in a controlled reaction that is maintained at normal criticality (KEffective = 1), each fission creates exactly one neutron that is used to produce another fission.
A neutron is an unstable particle outside a nucleus but to start nuclear fission requires the slowing down of a neutron. How is nuclear fusion carried out in the case of uranium?
The neutrons released from Uranium are fast neutrons. In a reactor they are slowed down by a moderator. The moderator could be water, heavy water, graphite, among others. When the neutron is slowed down, it is more likely to create fission.This is what happens with the U-235. The U-238 does not fission, but it does transmute through a series of neutron absorption and beta decay etc. into plutonium which does fission also.
The energy from nuclear fission is released as heat?
Initially as kinetic energy of the fission fragments, but this is quickly converted to thermal energy as they are slowed down in the mass of the fuel.
Is The energy from nuclear fission is released as heat.?
Initially as kinetic energy of the fission fragments, but this is quickly converted to thermal energy as they are slowed down in the mass of the fuel.
Is the energy of nuclear fission released as heat?
Yes, as heat and radiation Nuclear fission actually releases first fission fragments and other particles with kinetic energy, which then turns to heat as the ejected fission fragments and part of the particles are slowed down within the mass of the solid fuel.
What is a nuclear reactor?
An assembly of fissile fuel (U-235 or PU-239) arranged in a geometric array. The assembly can be made to go critical such that a chain reaction starts which builds up a neutron flux inside the assembly. The chain reaction is controlled at a steady level using neutron absorbing control rods.The nuclear reactor can classified under:a thermal nuclear reactor, where the majority of fissions are caused by slow neutrons. In these reactors, the fast neutrons produced by fissions are slowed down with a moderator which can be graphite, heavy water or light water, anda fast nuclear reactor where the majority of fissions are caused by fast neutrons
What defines the process in a nuclear reactor that reduces the speed of neutrons so they can be captured by the reactor fuel in order to continue the chain reaction?
You did not provide the list of "the following". However, the answer to the question is moderation. Moderation is the process whereby the neutron is slowed down in order to facilitate its subsequent capture by the nuclei of the fuel.
What type of energy is nuclear energy?
Nuclear energy is released in fission when a nucleus is split. A small proportion of the mass of the nucleus is annihilated and converted to free energy. Initially this appears as the kinetic energy of the fission fragments, this is quickly converted to thermal energy as the fragments are slowed down.
Why does an atomic bomb explode?
It explodes because it contains a critical mass of unstable atoms of a heavy metal such as Uranium-235 or Plutonium-239. When the nucleus of one of these large atoms is hit by a neutron, the atom splits into two medium-size atoms such as Barium and Krypton or Strontium and Xenon, and also releases 2 or more free neutrons and a burst of energy. This process is called Nuclear Fission. The free neutrons from one nuclear fission can then create more fissions, and a Chain Reaction is begun. More fissions release more neutrons which create more fissions which release even more neutrons, etc. If conditions are right, this chain reaction proceeds explosively to form a Nuclear Fission Bomb or "Atomic Bomb". If this chain reaction is slowed and controlled, then the nuclear fission produces heat energy which can be used to boil water in a Nuclear Power Plant. Rapid fission, nuclear bomb. Slow controlled fission, nuclear power plant.
What type of nuclear reaction is used n power plants?
Most nuclear power stations have pressurized water thermonuclear reactors. The nuclear reactions that take place in these reactors are fission (atom splitting) and nuclear decay. (Let's not split hairs so we can concentrate on splitting atoms.) In simple terms, these reactors work by fission of enriched uranium, which is uranium with a higher-than-natural amount of the U235 isotope. This isotope has a higher probability of capturing a neutron and splitting than other stuff. That's the fission part. After the uranium splits, neutrons are released and these can be used to make more fissions if they are slowed (thermalized). Links to Wikipedia are provided. There must be some consideration given to the fission products. These are the "broken pieces" left after an atom splits. There are a fair number of these and they continue to decay. Their half lives and decay schemes vary, and an interested party would review the Wikipedia article to get the low down on them. A link is provided.
What is nuclear reactors?
An assembly of fissile fuel (U-235 or PU-239) arranged in a geometric array. The assembly can be made to go critical such that a chain reaction starts which builds up a neutron flux inside the assembly. The chain reaction is controlled at a steady level using neutron absorbing control rods.The nuclear reactor can classified under:a thermal nuclear reactor, where the majority of fissions are caused by slow neutrons. In these reactors, the fast neutrons produced by fissions are slowed down with a moderator which can be graphite, heavy water or light water, anda fast nuclear reactor where the majority of fissions are caused by fast neutrons
