Nuclear Energy or Nuclear power conversion Technology

Energy conversion is the process of changing one form of energy into another, a fundamental capability that enables modern civilization to function. It can occur in various ways, from converting the kinetic energy of wind into mechanical power through windmills to transforming solar energy into electrical energy in solar panels. This transformation is essential not just for daily usage but also for harnessing and utilizing natural resources more efficiently. In the context of rural electrification, this process plays a critical role. By converting available local energy resources into electricity, rural communities can access a stable and reliable power supply. This not only improves the quality of life but also supports economic development by powering homes, schools, businesses, and healthcare facilities. Consequently, energy conversion facilitates the broader goal of rural electrification, demonstrating the interconnection between technological innovation and societal advancement.

1. Chapter - Four Nuclear Power Plants ‘First man splitted the atom now the atom splits man’. Gerhard Uhlenbruck (German physist ) Introduction: A nuclear power plant is similar to a conventional thermal power plant: Each type uses steam to drive a turbine generator that produces electricity . Unlike a fossil- fueled plant, the nuclear plant’s energy does not come from the combustion of fuel , but from the fissioning (splitting) of fuel atoms.

2. Nuclear Fuels In nuclear plants, no burning or combustion process is takes place but nuclear fission is used instead. The fission reaction generates heat, and this heat is transferred to the water that produces the steam. The fission process requires a particular kind of heavy element, such as uranium or plutonium , as a basic material.

3. Cont.… The most common fuel for the electrical producing reactor plants is uranium element . The U-235 is a more desirable atom for fuel, because it is easier to cause the U-235 atoms for fission (split) process. 1 kg of Uranium U 235 can produce as much energy as the burning of 4500 tones of high grade variety of coal.

4. Fission and Fusion Process All of the energy we produce comes from basic chemical and physical processes. Fission and fusion are two physical processes that produce massive amounts of energy from atoms (U-235). They yield millions of times more energy than other sources through nuclear reactions .

5. Cont.… Fission It occurs when a neutron slams into a larger atom, forcing it to excite and spilt into two smaller atoms-also known as fission products . Additional neutrons are also released that can initiate a chain reaction . When each atom splits, a large amount of energy is released .

6. Cont.… The energy released by fission in nuclear reactors heats water into steam. The steam is used to spin a turbine to produce carbon-free electricity. U-235 nucleus Ba-141 nucleus e n e r gy Kr-92 nucleus

7. N u clear c hain r eacti o n proton neutron U - 23 5 nu c l e us Neu t r o n s r elea s ed i n fi s si o n t r i g g e r t h e f issions of ot h e r nuc l e i

8. Cont.… Fusion: Fusion occurs when two atoms slam together to form a heavier atom , like when two hydrogen atoms fuse to form one helium atom.

9. Cont.… Figure: A typical fission and fusion reaction

10. Cont.… (a)

11. Cont.… (b) Figure: (a)&(b) fission V s fusion reaction

12. Nuclear Reactor Nuclear reactors are  the heart of a nuclear power plant which contain and control nuclear chain reactions that produce heat through a physical process called fission . The main job of a reactor is to house and control  nuclear fission , a process where atoms split and release energy .      Reactors use uranium for nuclear fuel. The uranium is processed into small ceramic pellets and stacked together into sealed metal tubes called fuel rods.

13. Cont.… A reactor core is typically made up of a couple hundred assemblies, depending on power level.  Inside the reactor vessel, the fuel rods are immersed in water which acts as both a coolant and moderator. The moderator helps slow down the neutrons produced by fission to sustain the chain reaction . The coolant is used to transfers heat in to another medium . Control rods can then be inserted into the reactor core to reduce the reaction rate.

14. Cont.. The heat created by fission turns the water into steam , which spins a turbine to produce carbon-free electricity. Generally The essential components of a reactor are: The fuel, which fissions to produce neutrons and to release energy; The control elements , which are used to set the energy release rate; and The cooling fluid, which removes the heat generated in the reactor.

15. Cont.. Figure: parts of nuclear reactor

16. Cont.. Uncontrolled nuclear reaction leads to fast chain reaction . The chain reaction is not slowed down T he rate of fission increases rapidly A huge amount of energy is released very quickly Nuclear bomb

17. Types of Water Reactor There are two types of water reactors which is used by nuclear reaction process. Boiling-Water Reactors Pressurized-Water Reactors

18. Boiling Water Reactors In this reactor, water enters the reactor and is heated as it passes up between the elements of nuclear fuel. Soon steam collects in the upper portion of the reactor and leaves through an outlet pipe . The pipes identified as "steam" and "water " would be connected to those similarly labelled in Figure below to form a complete power plant.

19. Figure: Boiling Water Reactor Cont..

20. Pressurized-Water Reactors A PWR generates steam indirectly by using two water circuits, a primary one and a secondary one. In a PWR (Fig below), heat from the reactor core is used to heat the primary water circuit at temperatures over 300°C. This water is kept liquid under high pressure. The heat from the primary water circuit is then transferred to the secondary circuit by way of the pressurized liquid. The secondary circuit then uses this heat to convert liquid water into steam for the turbine via steam generator . The steam is later condensed and recycled.

21. Figure: Pressurized Water Reactor (b ) Cont..

22. Nu c l e a r P o w e r P l a nt wi th PWR control rods fuel rods reactor p r essu r e vessel w a t e r ( c oo l ) ( h ig h water p r essu r e ) ( l o w water p r ess u r e ) coolant out coolant in steam condenser steam (low pressure) t u r b i n e e l e c t r i c power steam g ene r a t o r steam (high pressure) pu mp reactor core w a t e r (hot) primary loop secondary loop generator pu mp

23. Radioactivity A Review of Atomic Terms Nucleons – particles found in the nucleus of an atom Neutrons Protons Atomic Number (Z) – number of protons in the nucleus. Mass Number (A) – sum of the number of protons and neutrons

24. Radioactivity - the spontaneous decomposition of a nucleus forming a different nucleus and producing one or more additional particles. Nuclear Equation - shows the radioactive decomposition of an element. 14 6 C → 14 7 N + -1 e Nuclear Forces – strong nuclear force holds neutrons and protons together to form a nucleus. Weak nuclear force operates within individual nucleons and gives rise to some kinds of radioactivity. Cont..

25. Cont.… Radioactivity is essentially a nuclear phenomenon and is a drastic process because the element changes its kind. It is spontaneous and an irreversible self- disintegrating activity because the element breaks itself. Those elements which exhibit this activity are called radioactive elements. E xamples: Uranium,polonium,radium,radon,ionium,thorium,actinium a nd m e so t h e o r iu m

26. Cont.… Types of Radioactive Decay T he r a di o a c ti v e r a dia ti o ns e mitt e d b y the r a di o ac ti v e e l e m e nts a r e fou n d t o c on s ist of the foll o wi n g : A lp h a r a ys or a lp h a p a r ti c l e s B e ta r a ys or b e ta p a r ti c l e s g a mm a r a ys or ph otons

27. Cont.… Alpha-particle production An alpha particle is identical to that of a helium nucleus. It consists of two neutrons and two protons. Examples: Net effect is loss of 4 in mass number and loss of 2 in atomic number.

28. Cont.… Beta-particle production Beta particle occurs when a neutron changes in to a proton and an electron . Examples: Net effect is to change a neutron to a proton.

29. Cont.… Gamma R ay Gamma ray – high energy photon Examples: Net effect is no change in mass number or atomic number.

30. Application of Radio Active Decay Medical use: Many diseases such as cancer are cured by radio therapy. Sterilization of medical instruments and food is another common application of radiation. Scientific use : Alpha particles emitted from the radio isotopes are used for nuclear reactions. Industrial use: Radio isotopes are used as fuel for atomic energy reactors.

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