CAREER POINT UNIVERSITY

NUCLEAR POWER PLANT- NUCLEAR FUSION

SUBMITTED BYMEGHA AGARWALK11566EE5TH SEM

CONTENTS NUCLEAR PLANTS INTRODUCTION RAW MATERIALS PLASMA WHY FUSION RESEARCH POWER PRODUCTION FUSION REACTOR FLOW DIAGRAM WORKING OF FUSION REACTOR FUSION IN OUR WORLD CONSIDERATIONS SAFETY AND THE ENVIRONMENT ADVANTAGES DISADVANTAGES CONCLUSION

FIRST NUCLEAR POWER PLANT

Electricity was generated for the first time ever by a nuclear reactor on December 20, 1951 at the EBR-I experimental station near Arco, Idaho in the United States.

On June 27, 1954, the world's first nuclear power plant to generate electricity for a power grid started operations at Obninsk, USSR.

The world's first commercial scale power station, Calder Hall in England opened in October 17, 1956.

INTRODUCTION Nuclear fusion is the process of making a single

heavy nucleus from two lighter nuclei. This process is called a nuclear reaction. It releases a large amount of energy. The nucleus made by fusion is heavier than either of the starting nuclei. However, it is not as heavy as the combination of the original mass of the starting nuclei. This lost mass is changed into lots of energy. This is shown in Einstein's famous E=mc2 equation.

Fusion happens in the middle of stars, like the Sun. 

Nuclear Fusion is the reaction that makes the Universe shine and lights up all of the stars including the one we are most familiar with, the sun. Nuclear Fusion is the process that mainly converts Hydrogen into Helium. This produces a tremendous amount of energy in the form of light and heat. The conversion of Hydrogen and Helium is the reaction that makes almost all life on Earth possible.

This is a diagram of the Proton-Proton chain reaction which is the major reactions that make fusion possible. As you can see on the right this reaction requires four hydrogen atoms. At the beginning two hydrogen atoms or 1H combine and produce one positron and one neutrino and then form a heavy hydrogen atom or a 2H atom which has a neutron in it. After this another 1H atom is joined to the 2H atom.

This produces a Gamma Ray and forms a light helium atom, which is designated as 3He. Two 3He’s then join together and produce two 1H atoms and form a regular helium atom which has two neutrons and two protons. The end product, the helium atom, is actually less massive than the four hydrogen atom’s added masses. This loss in mass is converted into the light and heat that make stars shine through the equation E=MC2.

Raw materials for fusion:

TRITIUM: Tritium is an isotope of hydrogen, which has two neutrons. It

does not occur naturally. It can however be easily produced form the neutron bombardment of lithium, which is naturally abundant. Currently accessible reserves of lithium could supply all the world’s energy demands for more than 1000 years.

DEUTERIUM: Deuterium is an isotope of hydrogen, which has one neutron. Its abundance is approximately 33 g of deuterium in every

cubic meter of water. As water is available in plenty, we have a whole lot of deuterium.

Plasma

What is Plasma? Plasma Confinement: Confinement refers to all the conditions

necessary to keep a plasma dense and hot long enough to undergo fusion.

Some general principles; Equilibrium, Stability and Conduction.

Why fusion research? Ever increasing energy demand.

Limited fossil fuels.

Global climate change.

Limited scope of renewable energy.

High energy output by fusion.

Power Production

Three methods have been proposed so far on how to produce power using nuclear fusion:

Steam Turbines Direct Conversion

Fusion reactor flow Diagram

Working of a fusion reactor

The fusion reactor will heat a stream of deuterium and tritium fuel to form high-temperature plasma. It will squeeze the plasma so that fusion can take place.

The lithium blankets outside the plasma reaction chamber will absorb high-energy neutrons from the fusion reaction to make more tritium fuel. The blankets will also get heated by the neutrons.

The heat will be transferred by a water-cooling loop to a heat exchanger to make steam.

The steam will drive electrical turbines to produce electricity.

The steam will be condensed back into water to absorb more heat from the reactor in the heat exchanger

Fusion in Our WorldThere are really two different uses of fusion in our world today: as a power source and as a weapon. Scientists and engineers have been trying for years to achieve a Fusion reactor. The picture on the right shows one of the largest prototype reactors in the world and is located in France. It is called JET which stands for Joint European Torus and it has now produced 16 megawatts of fusion power. It is the largest magnetic confinement fusion research facility in the world and is built in the tokamak design. The tokamak design uses magnetic fields to contain super hot plasma that contains the hydrogen. There are also several other designs like Inertial confinement fusion which uses lasers to ignite a pellet of hydrogen and create fusion. Nuclear fusion is also used in making weapons of mass destruction such as the Hydrogen bomb, otherwise known as the H-bomb. These H-bombs are over 450 times more powerful than the bomb dropped on Nagasaki. Most modern H-bombs use lithium deuteride as their fusion fuel, but older H-bombs actually used liquefied deuterium, otherwise known as heavy hydrogen for fuel.

Considerations Any power plant using hot plasma, is going to have plasma

facing walls. In even the simplest plasma approaches, the material will get blasted with matter and energy. This leads to a minimum list of considerations, including dealing with:

A heating and cooling cycle, up to a 10 MW/m² thermal load.

Neutron radiation, which over time leads to neutron activation.

High energy ions leaving at tens to hundreds of electron volts.

Alpha particles leaving at millions of electron volts. Electrons leaving at high energy. Light radiation (IR, visible, UV, X-ray).

Safety & the Environment

Accident Potential: There is no possibility of a catastrophic accident in a fusion reactor resulting in major release of radioactivity to the environment or injury to non-staff, unlike modern fission reactors.

Effluents during normal: The natural product of the fusion reaction is a small amount of helium, which is completely harmless to life.

Waste management: There is very lesser amount of radioactivity produced when compared to a fission reaction and that too burns off within a very small time.

As a sustainable energy source: It is a very sustainable source of energy as the reserves of deuterium are supposed to last for a very long time along with lithium, which is also supposed to last for about 3000 years.

Reliable Power: Fusion power plants should provide a base load supply of large amounts of electricity, at costs that are estimated to be broadly similar to other energy sources.

Advantages Environment friendly as no greenhouse

gases are produced. Virtually limitless fuel is available as

the stocks are supposed to last for a really long time.

No chain reaction. So no chances of major accidents as the reactions can be stopped anytime by just cutting off the supply of the fuel which is also quite low.

The cost of the fuel is very low. Can be used for interstellar space

where solar energy is not available. Some problems like fresh water

shortages can also be solved because they exist mainly because of the power shortages.

Disadvantages Unproven till now at a commercial

scale. Initial experiments have been very

costly. The energy required to initiate is

greater than what’s generated. The material for setups has to be

worked upon so that it can take the excessive temperatures produced during the process.

Conclusion This initial investment will be

worthwhile if fusion will turn out to be an economical way to generate power.

Having negligible negative impact to the nature, fusion promises to be the answer to our energy crisis.

Thank you