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Overview on Thorium Breeder Reactor for Nuclear Power Plant

Prepared By:Md. Mustafa Zaved (101628002)

Dept. ofNuclear Science & Engineering

2Military Institute of Science and Technology (MIST)

Breeder Reactor

• A nuclear reactor that generates new fissile material at a greater rate than it consumes such material

• Excess neutrons generated in the fission reaction are absorbed by the fertile isotope, which is transmuted to a fissile isotope

• Breeders can be designed to utilize thorium, which is more abundant than uranium• Generate less waste, for equal amounts of energy, by converting non-fissile isotopes

of uranium into nuclear fuel• The breeder reactor holds out enticing promises of reducing the cost of electric

power generation and reducing its effect on the environment• Breeder reactors can utilize nearly 100% of the energy contained in uranium and

thorium ores

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Types of Breeder Reactor

Breeder Reactor

Fast Breeder Reactor Thermal Breeder Reactor• A thermal reactor uses moderator to

slow down neutrons substantially• Thermal neutrons are more efficient

at converting thorium-232 into uranium-233

• Water can be used as a coolant for a thermal reactor

• Thorium-232 produces uranium-233 after neutron capture and beta decay

• A fast reactor is a nuclear reactor which does not use a moderator - a substance that slows down neutrons

• Fast neutrons are more efficient at converting uranium-238 into plutonium

• Water cannot be used as a coolant for a fast reactor because water is a moderator. Usually they use liquid metals or inert gases as the coolant - mostly sodium or helium

• The first breeder reactor first transforms the 99.3% in the original ore abundant fertile isotope U-238 into fissile Pu-239

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Why Thorium instead of Uranium

1. It is three times more abundant than uranium in the Earth’s crust

2. Thorium reactors can be fast or thermal breeder reactors

3. It produces the more neutrons per fission

4. Has higher thermal conductivity and melting point

5. Easier to run the reactor safely

6. Fewer minor actinides are produced

7. Remaining ones have shorter half life

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Thorium Cycle

• Uses thorium Th-232 as fertile material• Th-232 captures a neutron to became U-233

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Various Types of Thorium Reactor

Thorium Reactor

Advanced Heavy Water

Reactor

Molten-salt breeder reactor (MSBR)

THTR-300

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Advanced Heavy Water Reactor

1. AHWR is a unique reactor designed in India for the large scale commercial utilization of thorium and integrated technological demonstration of the thorium cycle

2. It is being developed at Bhabha Atomic Research Centre (BARC), in Mumbai

3. The AHWR is a pressure tube type of heavy water reactor

4. A unique feature of this design is a large tank of water on top of the primary containment vessel, called the gravity-driven water pool (GDWP)

5. The overall design of the AHWR is to utilize large amounts of thorium and the thorium cycle

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Molten-salt breeder reactor (MSBR)

1. It is also known as Liquid Fluoride Thorium Reactor

2. A concept of American origin and evolution. When the United States started work on a nuclear-powered aircraft in 1947

3. Uses graphite as moderator4. Salts are the key to the MSBR5. The fuel is a liquid called the fuel salt

and consists of a combination of four fluorine-salt compounds

6. The metals used with fluorine to form the salts are uranium, thorium, lithium, and beryllium

7. The uranium and thorium are the fissionable and fertile materials used in the breeding process

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Thorium High-Temperature Nuclear Reactor (THTR-300)

1. The German state of North Rhine Westphalia financed the THTR-300’s construction

2. The THTR-300 was a helium-cooled high-temperature reactor

3. Graphite is the THTR main component of the fuel assemblies

4. Electrical output of THTR-300 is 300 megawatts

5. It is a pebble bed type reactor use the TRISO pebble fuel

6. Each fuel assembly contained about 1 g 235 U and about 10 g 232 Th in the form of mixed oxides of two heavy metals

7. THTR-300 was only in full service for 423 days and was deactivated due to its rising cost

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https://en.wikipedia.org/wiki/Thorium_fuel_cyclehttp://rationalwiki.org/wiki/Breeder_reactor#Fast_vs_thermal_breeder_reactorshttp://thoriumsingapore.com/content/index.php?option=com_content&view=article&id=75:breeder-reactors&catid=27:new-to-nuclear&Itemid=70http://energyfromthorium.com/lftr-overview/http://www.barc.gov.in/reactor/ahwr.pdf

References

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12Military Institute of Science and Technology (MIST)