Nuclear Energy Dawn of Nuclear Age

1. Nuclear Energy Dawn of Nuclear Age

2. History • Introduction to Nuclear Energy • Atoms and radioactivity • Pros and Cons of Nuclear Energy • Future of Nuclear Power Overview

3. Early History of Nuclear Power

4. Development of nuclear power 1954 the first nuclear power plant in USSR 1957 first commercial nuclear power plant in USA At present there are more than 440 nuclear power plants in the World

5. 1938– Scientists study Uranium nucleus 1941 – Manhattan Project begins 1942 – Controlled nuclear chain reaction 1945 – U.S. uses two atomic bombs on Japan 1949 – Soviets develop atomic bomb 1952 – U.S. tests hydrogen bomb 1954: first commercial nuclear power program 1955 – First U.S. nuclear submarine History of nuclear power

6. Secret government project to create atomic weapons during World War II • After the war, the government encouraged “the development of nuclear energy for peaceful civilian purposes.” • This led to the technology used in nuclear plants today Manhattan Project

7. power was gradually increased until the first usable amount of electricity was generated, lighting four light bulbs and introducing nuclear generated power for the first time • In 1953, the EBR-1 was creating one new atom of nuclear fuel for every atom burned, thus the reactor could sustain its own operation • With this creation of new cores, enough energy was created to fuel additional reactors • A few years later, the town of Arco, Idaho became the world's first community to get its entire power supply from a nuclear reactor • This was achieved by temporarily attaching the town’s power grid to the reactor’s turbines

8. Atomic Energy Commission (AEC) established by Congress in 1946 as part of the Atomic Energy Act • AEC authorized the construction of Experimental Breeder Reactor I ( EBR-1) at a site in Idaho in 1949 Early Beginning of Commission

9. Began in 1953 and was designed by Eisenhower specifically to promote peaceful, commercial applications of atomic energy after the Manhattan Project and atomic bombings on Japan • Public support for nuclear energy grew, federal nuclear energy programs shifted their focus to advancing reactor technologies • With this came the support of utility companies, which saw nuclear energy as a cheap and environmentally safe alternative energy choice Program to justify nuclear technology Proposals for power, canal-building, exports First commercial power plant, Illinois 1960 Atoms for Peace

10. 17% of world’s electricity from nuclear power • U.S. about 20% (2nd largest source) • Leader is France • About 80% of its power from nuclear • 440+ nuclear plants in 31 countries • 103 of them in the U.S. • Built none since 1970s (Wisconsin as leader). Nuclear power Today around the globe

11. Countries Generating Most Nuclear Power

12. Introduction to Nuclear Energy

13. Previous studies have taught us that “matter and energy cannot be created nor destroyed” • We now need to understand that Matter and Energy are two forms of the same thing Matter and Energy

14. Matter can be changed into Energy • Einstein’s formula above tells us how the change occurs • In the equation above: E = Energy m = Mass c = Speed of Light (Universal Constant) • The equation may be read as follows: Energy (E) is equal to Mass (m) multiplied by the Speed of Light (c) squared • This tells us that a small amount of mass can be converted into a very large amount of energy because the speed of light (c) is an extremely large number E = mc2 Light Speed Energy Mass

15. Nuclear reactions deal with interactions between the nuclei of atoms • Both fission and fusion processes deal with matter and energy Introduction to Nuclear Energy

16. Nuclear energy • Energy released by nuclear fission or fusion • Nuclear fission • Splitting of an atomic nucleus into two smaller fragments, accompanied by the release of a large amount of energy • Nuclear fusion • Joining of two lightweight atomic nuclei into a single, heavier nucleus, accompanied by the release of a large amount of energy Introduction to Nuclear Energy

17. Fission is the process of splitting an atomic nucleus into fission fragments • The fission fragments are generally in the form of smaller atomic nuclei and neutrons • Large amounts of energy are produced by the fission process • Fissile nuclei are generally heavy atoms with large numbers of nucleons • The nuclei of such heavy atoms are struck by neutrons initiating the fission process • Fission occurs due to electrostatic repulsion created by large numbers of protons within the nuclei of heavy atoms Fission

18. A classic example of a fission reaction is that of U-235: U-235 + 1 Neutron 2 Neutrons + Kr-92 + Ba-142 + Energy • In this example, a stray neutron strikes an atom of U-235. It absorbs the neutron and becomes an unstable atom of U-236. It then undergoes fission. Notice that more neutrons are released in the reaction. These neutrons can strike other U-235 atoms to initiate their fission. Fission

19. Fusion is a nuclear reaction whereby two light atomic nuclei fuse or combine to form a single larger, heavier nucleus • The fusion process generates tremendous amounts of energy; refer back to Einstein’s equation • For fusion to occur, a large amount of energy is needed to overcome the electrical charges of the nuclei and fuse them together • Fusion reactions do not occur naturally on our planet but are the principal type of reaction found in stars • The large masses, densities, and high temperatures of stars provide the initial energies needed to fuel fusion reactions • The sun fuses hydrogen atoms to produce helium, subatomic particles, and vast amounts of energy Fusion

20. Way of the future?? • Produces no high-level waste • Fuel is hydrogen (plenty of it!) • Problems • It takes very high temperatures (millions of degrees) to make atoms fuse • Confining the plasma after it is formed • Scientists have yet to be able to create energy from fusion Fusion

21. Nucleus • Comprised of protons (+) and neutrons (neutral) • Electrons (-) orbit around nucleus • Neutral atoms • Same number of protons and electrons Atoms and Radioactivity

22. Atomic mass • Sum of the protons and neutrons in an atom • Atomic number • Number of protons per atom • Each element has its own atomic number • Isotope • Atoms of an element having same number of protons but different number of neutrons Atoms and Radioactivity

23. Unstable isotope • Radioactive Decay • Emission of energetic particles or rays from unstable atomic nuclei • Each isotope decays based on its own half-life • Half-life of U-238 is 4.468×109 years • Half life of U-235 is 7.04× 108 years Radioactive Isotope

24. Radioactive Isotope Half-lives

25. processes involved in producing the fuel used in nuclear reactors and in disposing of radioactive (nuclear) wastes Nuclear Fuel Cycle

26. How Electricity is Produced

27. Pros • Less of an immediate environmental impact compared to fossil fuels Pros and Cons of Nuclear Energy

28. Pros (continued) • Carbon-free source of electricity- no greenhouse gases emitted • May be able to generate H-fuel • Cons • Generates radioactive waste • Many steps require fossil fuels (mining and disposal) • Expensive Pros and Cons of Nuclear Energy

29. Cost is very high • 20% of US electricity is from Nuclear Energy • Affordable due to government subsidies • Expensive to build nuclear power plants • Long cost-recovery time • Fixing technical and safety issues in existing plants is expensive Cost of Electricity from Nuclear Energy

30. Meltdown • At high temperatures the metal encasing the uranium fuel can melt, releasing radiation • Probability of meltdown or other accident is low • Public perception is that nuclear power is not safe • Sites of major accidents: • Three Mile Island • Chornobyl (Ukraine) Safety Issues in Nuclear Power Plants

31. 31 countries use nuclear energy to create electricity • These countries have access to spent fuel needed to make nuclear weapons • Safe storage and handling of these weapons is a concern Nuclear Energy and Nuclear Weapons

32. Low-level radioactive waste- • Radioactive solids, liquids, or gasses that give off small amounts of ionizing radiation • High-level radioactive waste- • Radioactive solids, liquids, or gasses that give off large amounts of ionizing radiation Radioactive Waste

33. Licensed to operate for 40 years • Several have received 20-year extensions • Power plants cannot be abandoned when they are shut down • Three solutions • Storage • Entombment • Decommissioning (dismantling) Decommissioning Nuclear Power Plants