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QUICK REVISION ( ARTICLE:3, SCIENCE): Type Of Nuclear Reactors
COMPONENTS OF NUCLEAR REACTOR:
Fuel: Usually pellets of uranium oxide (UO2) arranged in tubes to form fuel rods. The rods are arranged into fuel assemblies in the reactor core
- Moderator: This is material which slows down the neutrons released from fission so that they cause more fission. It is usually water, but may be heavy water or graphite.
- Control rods: These are made with neutron-absorbing material such as cadmium, hafnium or boron, and are inserted or withdrawn from the core to control the rate of reaction, or to halt it. (Secondary shutdown systems involve adding other neutron absorbers, usually as a fluid, to the system.)
- Coolant: A liquid or gas circulating through the core so as to transfer the heat from it. In Light water reactors the moderator functions also as coolant.
- Pressure vessel or pressure tubes: Usually a robust steel vessel containing the reactor core and moderator/coolant, but it may be a series of tubes holding the fuel and conveying the coolant through the moderator.
- Steam Generator: Part of the cooling system where the heat from the reactor is used to make steam for the turbine.
- Containment system: The structure around the reactor core which is designed to protect it from outside intrusion and to protect those outside from the effects of radiation in case of any malfunction inside. It is typically a metre-thick concrete and steel structure.
Most of the nuclear reactors work on the principle of nuclear fission. The energy released in the reaction is used to turn water into steam. The steam is used to run the turbine.
Diff types of nuclear reactor:
| Type of reactor | Characteristics |
| Light water reactor | 1. Boiling water reactor · Reactor core heats water which turns to steam and then drives a steam turbine. 2. Pressurised water reactor: · Reactor core heats water which does not boil. Pressurised water can reach upto higher temperature. This water energy is transferred to secondary low pressure water system. |
| Heavy water reactor | Heavy water is used as a moderator. Heavy water does not readily absorb the neutrons as readily as water. The use of heavy water increases the Probability of fission in U-235. It increases the probability of sustained chain reaction. |
| Gas cooled reactors | High thermal efficiency and can operate at very high temperature. |
| Fast reactors | They can operate on fast neutrons. The need of moderator is not there. But to sustain the chain reaction, fission material needs to be highly enriched . High amount of fuel is also required and this is a costly affair. They use liquid sodium as coolant. |
| Breeder reactor | A breeder reactor is a nuclear reactor capable of generating more fissile material than it consumes because its neutron economy is high enough to breed fissile fuel from fertile material like U-238 or thorium-232.
For every 1kg of fuel used in the rod, 1.1 kg comes out of the reaction. |
| Thorium Reactors | Thorium 232 is a fertile material.
Th-232 converts into Th-233. Th-233 converts into Protactinium-233. Pa-233 converts into U-233. U-233 releases energy via nuclear fission. |
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Nuclear power is a hotly debated topic. Some people believe that it is a clean and efficient way to generate electricity, while others are concerned about the risks of nuclear accidents and the disposal of nuclear waste.
There are many Different types of nuclear reactors, each with its own advantages and disadvantages. The most common type of nuclear reactor is the pressurized water reactor (PWR). PWRs use ordinary water as both a coolant and a moderator. The water is heated under high pressure to produce steam, which drives a turbine to generate electricity.
Another common type of nuclear reactor is the boiling water reactor (BWR). BWRs are similar to PWRs, but the water in the reactor vessel is allowed to boil. The steam produced by the boiling water is then used to drive a turbine to generate electricity.
Pressurized heavy water reactors (PHWRs) use heavy water, which is water that contains a higher proportion of deuterium than ordinary water, as both a coolant and a moderator. PHWRs are used in Canada and India.
Advanced gas-cooled reactors (AGRs) use carbon dioxide gas as a coolant. AGRs are used in the United Kingdom.
Fast breeder reactors (FBRs) use fast-neutron fission to breed more fissile material than they consume. FBRs are not currently in commercial use, but they are being developed as a potential future source of nuclear power.
Molten salt reactors (MSRs) use molten salt as a coolant and a moderator. MSRs are being developed as a potential future source of nuclear power.
Liquid Metal fast reactors (LMFRs) use liquid sodium as a coolant. LMFRs are being developed as a potential future source of nuclear power.
Sodium-cooled fast reactors (SFRs) use liquid sodium as a coolant. SFRs are being developed as a potential future source of nuclear power.
Gas-cooled fast reactors (GFRs) use helium gas as a coolant. GFRs are being developed as a potential future source of nuclear power.
Lead-cooled fast reactors (LFRs) use liquid lead as a coolant. LFRs are being developed as a potential future source of nuclear power.
Thorium-fueled molten salt reactor (TMSR) uses thorium as a fuel. TMSRs are being developed as a potential future source of nuclear power.
Pebble bed modular reactor (PBMR) uses graphite as a moderator and pebbles containing uranium fuel as the fuel. PBMRs are being developed as a potential future source of nuclear power.
Generation IV reactors are a new generation of nuclear reactors that are being developed to address some of the challenges of current nuclear reactors. Generation IV reactors are designed to be more efficient, safer, and more proliferation-resistant than current nuclear reactors.
Nuclear power has the potential to provide a clean and efficient source of electricity. However, there are also risks associated with nuclear power, such as the risk of nuclear accidents and the disposal of nuclear waste. It is important to weigh the risks and benefits of nuclear power before making a decision about whether or not to support it.
What are the different types of nuclear reactors?
There are four main types of nuclear reactors: light water reactors (LWRs), heavy water reactors (HWRs), gas-cooled reactors (GCRs), and fast breeder reactors (FBRs).
LWRs are the most common type of nuclear reactor. They use ordinary water as both a coolant and a moderator. HWRs use heavy water, which is water that contains a higher proportion of deuterium than ordinary water. GCRs use carbon dioxide gas as a coolant. FBRs use a fast-neutron reactor that uses a liquid metal coolant.
How do nuclear reactors work?
Nuclear reactors work by splitting atoms of uranium-235 or plutonium-239. This process, called fission, releases a large amount of energy. The energy released by fission is used to heat water, which turns into steam. The steam then drives a turbine, which generates electricity.
What are the advantages of nuclear power?
Nuclear power is a clean and efficient Source Of Energy. It does not produce greenhouse gases, and it does not require large amounts of land. Nuclear power is also a reliable source of energy, as it can operate 24 hours a day, 7 days a week.
What are the disadvantages of nuclear power?
The main disadvantage of nuclear power is the risk of accidents. Nuclear accidents can release large amounts of radiation, which can cause serious Health problems. Nuclear power Plants also produce radioactive waste, which must be carefully disposed of.
What is the future of nuclear power?
The future of nuclear power is uncertain. Some countries are planning to build new nuclear power plants, while others are considering phasing out nuclear power. The decision of whether or not to build new nuclear power plants will depend on a number of factors, including the cost of nuclear power, the risk of accidents, and the availability of other sources of energy.
Question 1
Which of the following is not a type of nuclear reactor?
(A) Pressurized water reactor (PWR)
(B) Boiling water reactor (BWR)
(C) Gas-cooled reactor (GCR)
(D) Fast breeder reactor (FBR)
Answer
(D)
Explanation
A fast breeder reactor is a type of nuclear reactor that uses fast neutrons to breed fissile material from fertile material. The other three types of nuclear reactors use thermal neutrons to generate heat.
Question 2
Which of the following is the most common type of nuclear reactor in the world?
(A) Pressurized water reactor (PWR)
(B) Boiling water reactor (BWR)
(C) Gas-cooled reactor (GCR)
(D) Fast breeder reactor (FBR)
Answer
(A)
Explanation
Pressurized water reactors are the most common type of nuclear reactor in the world, accounting for about 60% of all nuclear reactors in operation. They are used to generate electricity in many countries, including the United States, Canada, France, and Japan.
Question 3
Which of the following is a type of nuclear reactor that uses light water as a coolant?
(A) Pressurized water reactor (PWR)
(B) Boiling water reactor (BWR)
(C) Gas-cooled reactor (GCR)
(D) Fast breeder reactor (FBR)
Answer
(A) and (B)
Explanation
Pressurized water reactors and boiling water reactors are both types of nuclear reactors that use light water as a coolant. Light water is ordinary water, which is made up of hydrogen and Oxygen atoms.
Question 4
Which of the following is a type of nuclear reactor that uses heavy water as a coolant?
(A) Pressurized water reactor (PWR)
(B) Boiling water reactor (BWR)
(C) Gas-cooled reactor (GCR)
(D) Heavy water reactor (HWR)
Answer
(D)
Explanation
A heavy water reactor is a type of nuclear reactor that uses heavy water as a coolant. Heavy water is water that contains a higher proportion of deuterium atoms than ordinary water. Deuterium is an isotope of hydrogen that has one proton and one neutron in its nucleus.
Question 5
Which of the following is a type of nuclear reactor that uses graphite as a moderator?
(A) Pressurized water reactor (PWR)
(B) Boiling water reactor (BWR)
(C) Gas-cooled reactor (GCR)
(D) Graphite-moderated reactor (GMR)
Answer
(D)
Explanation
A graphite-moderated reactor is a type of nuclear reactor that uses graphite as a moderator. A moderator is a material that slows down neutrons so that they can be captured by fissile material. Graphite is a good moderator because it is a good conductor of heat and it does not absorb neutrons.