Group MemberGroup Member

Usman Tariq 07-MCT-14Usman Tariq 07-MCT-14

Badar Ali 07-MCT-21Badar Ali 07-MCT-21

Jamal Abdullah 07-MCT- 47Jamal Abdullah 07-MCT- 47

Nuclear Fission ReactorNuclear Fission Reactor

A nuclear reactor is a device in which A nuclear reactor is a device in which nuclear chain reactionsnuclear chain reactions are initiated, are initiated, controlled, and sustained at a steady rate, controlled, and sustained at a steady rate, as opposed to a as opposed to a nuclear bombnuclear bomb, in which the , in which the chain reaction occurs in a fraction of a chain reaction occurs in a fraction of a second and is uncontrolled causing an second and is uncontrolled causing an explosion. explosion.

The existence of this phenomenon was The existence of this phenomenon was discovered in discovered in 19721972 by by FrenchFrench physicistphysicist Francis Perrin. Francis Perrin.

The Basics of Nuclear The Basics of Nuclear Energy Energy

When an atom of uranium-235 is hit by a When an atom of uranium-235 is hit by a neutronneutron there is a high probability of a violent there is a high probability of a violent reaction, but if the atom is one of uranium-reaction, but if the atom is one of uranium-238 the probability is very low. The reaction 238 the probability is very low. The reaction is known as is known as nuclear fission nuclear fission or splitting of the or splitting of the atom.atom.

continuation….continuation…. Therefore we need to have Uranium 235 in Therefore we need to have Uranium 235 in

its pure form to have Fission reactrions.its pure form to have Fission reactrions.

The fission-product atoms contain excess The fission-product atoms contain excess energy, most as motion which rapidly energy, most as motion which rapidly becomes heat, and some of which is emitted becomes heat, and some of which is emitted over time as over time as radiationradiation , i.e., the atoms are , i.e., the atoms are radioactive.radioactive.

In addition to the fission products, two or In addition to the fission products, two or three neutrons are emitted when an atom three neutrons are emitted when an atom fissions. If one of these causes fission in fissions. If one of these causes fission in another fissile atom more neutrons are another fissile atom more neutrons are emitted, one of which could possibly cause a emitted, one of which could possibly cause a further fission, and so on in a further fission, and so on in a chain reaction.chain reaction.

The Nuclear Fuel CycleThe Nuclear Fuel Cycle

The nuclear fuel cycle is the series of industrial The nuclear fuel cycle is the series of industrial processes which involve the production of processes which involve the production of electricity from uranium in nuclear power reactors. electricity from uranium in nuclear power reactors.

Uranium is a relatively common element that is Uranium is a relatively common element that is found throughout the world. It is mined in a found throughout the world. It is mined in a number of countries and must be processed number of countries and must be processed before it can be used as fuel for a nuclear reactor. before it can be used as fuel for a nuclear reactor.

Electricity is created by using the heat generated Electricity is created by using the heat generated in a nuclear reactor to produce steam and drive a in a nuclear reactor to produce steam and drive a turbine connected to a generator.turbine connected to a generator.

Fuel removed from a reactor, after it has reached Fuel removed from a reactor, after it has reached the end of its useful life, can be reprocessed to the end of its useful life, can be reprocessed to produce new fuel.produce new fuel.

Stages of the Nuclear Fuel CycleStages of the Nuclear Fuel Cycle

The nuclear fuel cycle uses uranium in The nuclear fuel cycle uses uranium in

different chemical and physical forms. Stages different chemical and physical forms. Stages of this cycle typically include the following:of this cycle typically include the following:

Mining (extracting from ore) and milling Mining (extracting from ore) and milling Conversion to uranium hexafluoride Conversion to uranium hexafluoride Enrichment Enrichment Fuel fabrication into uranium oxide Fuel fabrication into uranium oxide Use of the fuel in nuclear power, research, or Use of the fuel in nuclear power, research, or

naval propulsion reactors naval propulsion reactors Interim Storage Interim Storage Reprocessing (currently not done in the U.S.) Reprocessing (currently not done in the U.S.) High-Level Waste High-Level Waste

Uranium MillingUranium Milling A uranium mill is a chemical plant that extracts uranium A uranium mill is a chemical plant that extracts uranium

from mined ore. from mined ore.

In a mill, uranium is extracted from the crushed and In a mill, uranium is extracted from the crushed and ground-up ore by leaching, in which either a strong acid or ground-up ore by leaching, in which either a strong acid or a strong alkaline solution is used to dissolve the uranium. a strong alkaline solution is used to dissolve the uranium.

EnrichmentEnrichment Enriching uranium increases the Enriching uranium increases the

amount of "middle-weight" and “light-amount of "middle-weight" and “light-weight” uranium atoms. weight” uranium atoms.

There are two enrichment processes There are two enrichment processes in large scale commercial use, each of in large scale commercial use, each of which uses uranium hexafluoride as which uses uranium hexafluoride as feed: feed:

(a) gaseous diffusion (a) gaseous diffusion

(b) gas centrifuge (b) gas centrifuge

Reactor Reactor

A nuclear reactor is a device in which nuclear chain reactions are initiated, controlled, and sustained at a steady rate, as opposed to a nuclear bomb, in which the chain reaction occurs in a fraction of a second and is uncontrolled causing an explosion.

Control room of a Nuclear Reactor

ReprocessingReprocessing

The uranium from reprocessing, which The uranium from reprocessing, which typically contains a slightly higher typically contains a slightly higher concentration of U-235 than occurs in concentration of U-235 than occurs in nature, can be reused as fuel after nature, can be reused as fuel after conversion and enrichment.conversion and enrichment.

The plutonium can be directly made into The plutonium can be directly made into mixed oxide (MOX) fuel, in which mixed oxide (MOX) fuel, in which uranium and plutonium oxides are uranium and plutonium oxides are combined combined

Material balance in the nuclear fuel Material balance in the nuclear fuel

cyclecycle

Mining:   20 000 tonnes of 1% uranium ore

Milling:   230 tonnes of uranium oxide concentrate (with 195 t U)

Conversion   288 tonnes UF6 (with 195 t U)

Enrichment   35 tonnes UF6 (with 24 t enriched U) - balance is 'tails'

Fuel fabrication   27 tonnes UO2 (with 24 t enriched U)

Reactor operation   8640 million kWh (8.64 TWh) of electricity at full output

Used fuel  27 tonnes containing 240kg plutonium, 23 t uranium

(0.8% U-235), 720kg fission products, also transuranics.

Fuel CycleFuel Cycle

Nuclear reactor Nuclear reactor technologytechnology

A nuclear reactor is a device in which A nuclear reactor is a device in which nuclear chain reactions are initiated, nuclear chain reactions are initiated, controlled, and sustained at a steady controlled, and sustained at a steady rate, as opposed to a nuclear bomb, rate, as opposed to a nuclear bomb, in which the chain reaction occurs in in which the chain reaction occurs in a fraction of a second and is a fraction of a second and is uncontrolled causing an explosion. uncontrolled causing an explosion.

Reactor Reactor types……….Classificationstypes……….Classifications

Classification by phase of fuelClassification by phase of fuel

Solid fueledSolid fueled Fluid fueledFluid fueled Gas FuledGas Fuled

Classification by generationClassification by generation

Generation I reactorGeneration I reactor Generation II reactorGeneration II reactor Generation III reactorGeneration III reactor Generation IV reactor Generation IV reactor

Generation IV reactorsGeneration IV reactors

Generation IV reactors are a set of Generation IV reactors are a set of theoretical nuclear reactor designs theoretical nuclear reactor designs currently being researched.currently being researched.

Categories of IV Generation Categories of IV Generation ReactorsReactors

Following are the main categories of iv Following are the main categories of iv generation Reactors;generation Reactors;

1. Gas cooled fast reactor1. Gas cooled fast reactor2.Lead cooled fast reactor2.Lead cooled fast reactor3.Molten salt reactor3.Molten salt reactor4.Sodium-cooled fast reactor4.Sodium-cooled fast reactor5.Supercritical water reactor5.Supercritical water reactor6.Very high temperature reactor 6.Very high temperature reactor

a) Thermal Reactorsa) Thermal Reactors 1.Very-High-Temperature Reactor 1.Very-High-Temperature Reactor

(VHTR)(VHTR) The The Very High Temperature ReactorVery High Temperature Reactor concept utilizes a concept utilizes a

graphite-moderated core with a once-through uranium fuel cycle. graphite-moderated core with a once-through uranium fuel cycle.

2.Supercritical-Water-Cooled 2.Supercritical-Water-Cooled Reactor (SCWR)Reactor (SCWR)

The The Supercritical water reactorSupercritical water reactor (SCWR) is a concept that (SCWR) is a concept that uses supercritical water as the working fluid. SCWRs are uses supercritical water as the working fluid. SCWRs are basically light water reactors (LWR) operating at higher basically light water reactors (LWR) operating at higher pressure and temperatures with a direct, once-through cycle. pressure and temperatures with a direct, once-through cycle.

3.Molten Salt Reactor (MSR)3.Molten Salt Reactor (MSR) A A molten salt reactormolten salt reactor is a type of nuclear reactor where is a type of nuclear reactor where

the coolant is a molten salt. There have been many designs the coolant is a molten salt. There have been many designs put forward for this type of reactor and a few prototypes put forward for this type of reactor and a few prototypes built. built.

(b) Fast reactors(b) Fast reactors1.Gas-Cooled Fast Reactor (GFR)1.Gas-Cooled Fast Reactor (GFR) The The Gas-Cooled Fast ReactorGas-Cooled Fast Reactor (GFR) system features a fast- (GFR) system features a fast-

neutron spectrum and closed fuel cycle for efficient conversion of neutron spectrum and closed fuel cycle for efficient conversion of fertile uranium and management of actinides. The reactor is fertile uranium and management of actinides. The reactor is helium-cooled, with an outlet temperature f 850 °C and using a helium-cooled, with an outlet temperature f 850 °C and using a direct Brayton cycle gas turbine for high thermal efficiency. direct Brayton cycle gas turbine for high thermal efficiency.

2.Sodium-Cooled Fast Reactor (SFR)2.Sodium-Cooled Fast Reactor (SFR)

The SFR is a project that builds on two The SFR is a project that builds on two closely related existing projects, the LMFBR closely related existing projects, the LMFBR and the Integral Fast Reactor.The reactor and the Integral Fast Reactor.The reactor design uses an unmoderated core running design uses an unmoderated core running on fast neutrons, designed to allow any on fast neutrons, designed to allow any transuranic isotope to be consumed (and in transuranic isotope to be consumed (and in some cases used as fuel). some cases used as fuel).

3.Lead-Cooled Fast Reactor (LFR)3.Lead-Cooled Fast Reactor (LFR)

The The Lead-cooled Fast ReactorLead-cooled Fast Reactor features a fast-neutron- features a fast-neutron-spectrum lead or lead/bismuth eutectic (LBE) liquid-metal-spectrum lead or lead/bismuth eutectic (LBE) liquid-metal-cooled reactor with a closed fuel cycle. Options include a cooled reactor with a closed fuel cycle. Options include a range of plant ratings, including a "battery" of 50 to range of plant ratings, including a "battery" of 50 to 150 MW of electricity that features a very long refueling 150 MW of electricity that features a very long refueling interval, a modular system rated at 300 to 400 MW, and a interval, a modular system rated at 300 to 400 MW, and a large monolithic plant option at 1,200 MW. (large monolithic plant option at 1,200 MW. (

Thanks You Very Thanks You Very Much.Much.

……Allah Hafiz…Allah Hafiz…