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Section 19. 3 Using the Nucleus as a Source of Energy Objectives 1. 2. Section 19. 3 Using the Nucleus as a Source of Energy Objectives 1. 2. 3. 4. 5. 6. To introduce fusion and fission as sources of energy To learn about nuclear fission To understand how a nuclear reactor works To learn about nuclear fusion To understand nuclear weapons To see how radiation damages human tissue

Section 19. 3 Using the Nucleus as a Source of Energy A. Nuclear Energy Section 19. 3 Using the Nucleus as a Source of Energy A. Nuclear Energy • Two types of nuclear processes can produce energy – Combining 2 light nuclei to form a heavier nucleus fusion – Splitting a heavy nucleus into 2 nuclei with smaller mass numbers - fission – Energy produced by conversion of mass, E = mc 2 • Sun converts 4 million tonnes per second Fusion and Fission POGIL

Section 19. 3 Using the Nucleus as a Source of Energy B. Nuclear Fission Section 19. 3 Using the Nucleus as a Source of Energy B. Nuclear Fission • Each atomic fission produces 3 neutrons • Releases 2. 1 1013 J/mol uranium-235 • (Burning methane produces 8. 90 x 105 J/mol)

Section 19. 3 Using the Nucleus as a Source of Energy B. Nuclear Fission Section 19. 3 Using the Nucleus as a Source of Energy B. Nuclear Fission • Chain reaction – self sustaining fission process caused by the production of neutrons that proceed to split other nuclei Chain Reaction Alternative CR • Critical mass – mass of fissionable material required to produce a chain reaction

Section 19. 3 Using the Nucleus as a Source of Energy C. Nuclear Reactors Section 19. 3 Using the Nucleus as a Source of Energy C. Nuclear Reactors

Section 19. 3 Using the Nucleus as a Source of Energy C. Nuclear Reactors Section 19. 3 Using the Nucleus as a Source of Energy C. Nuclear Reactors Reactor core Nuclear Power Plants

Section 19. 3 Using the Nucleus as a Source of Energy B. Nuclear Fission Section 19. 3 Using the Nucleus as a Source of Energy B. Nuclear Fission Chernobyl 1 Chernobyl 2 Chernobyl 3 Nuclear Energy in the US?

Section 19. 3 Using the Nucleus as a Source of Energy D. Nuclear Fusion Section 19. 3 Using the Nucleus as a Source of Energy D. Nuclear Fusion • Process of combining two light nuclei • Produces more energy per mole than fusion • Powers the stars and sun

Section 19. 3 Using the Nucleus as a Source of Energy D. Nuclear Fusion Section 19. 3 Using the Nucleus as a Source of Energy D. Nuclear Fusion • Atoms lighter than Fe. Deuterium used • Requires extremely high temperatures ~ 1 billion K • Currently not technically possible for use as a power source – issues with confinement • Used as “Hydrogen bomb” • Sun’s energy captured for our use

Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Binding Energy Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Binding Energy

Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Weapons Fission Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Weapons Fission Weapons (“Atomic Bombs”) − Enriched uranium or plutonium − Supercritical mass produced in bomb − Limited up to 500 kilotons of TNT − Twice used in warfare (Hiroshima and Nagasaki)

Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Weapons Fusion Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Weapons Fusion Weapons (“Thermonuclear / Hydrogen Bombs”) − deuterium and tritium − fission bomb compresses and heats hydrogen fuel − further stages of fission reactions (depleted uranium) − largest so far is 57 megatons (“Tsar Bomba” - USSR) Radioactive fallout can be regulated – salted, neutron bomb

Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Weapons “Now Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Weapons “Now I am become Death, the destroyer of worlds” Delivery − Gravity bombs − Missiles (land or submarine launch) − Multiple Independent Re-entry Vehicles − “Tactical” weapons: shells, torpedoes Strategy − “Cold War, Arms Race” − “Mutually Assured Destruction” − Missile Defense − Terrorist Threat WWII 1 2 3 4

Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Weapons Regulation Section 19. 3 Using the Nucleus as a Source of Energy Nuclear Weapons Regulation − UN, International Atomic Energy Agency − Test Ban and Nuclear Non-Proliferation Treaties − SALT’s and START’s (limitation and reduction) − Still enough to destroy most human life on Earth (23, 000 bombs equivalent to 150, 000 Hiroshima bombs) − US, Russia, China, UK, France, India, Pakistan, North Korea, Israel (? ), South Africa (X) − Obama (“World without nuclear weapons”)

Section 19. 3 Using the Nucleus as a Source of Energy E. Effects of Section 19. 3 Using the Nucleus as a Source of Energy E. Effects of Radiation Factors Determining Biological Effects of Radiation • • Energy of the radiation Penetrating ability of the radiation Ionizing ability of the radiation Cell repair, death (high dose / acute damage), incorrect repair (low dose / cancer) • Chemical properties of the radiation source − Strontium-90 and Radium-226 behave similarly to calcium so tend to accumulate in bones. Radioactive Iodine concentrates in the thyroid

Section 19. 3 Using the Nucleus as a Source of Energy Penetrating Ability of Section 19. 3 Using the Nucleus as a Source of Energy Penetrating Ability of Radiation Alpha radiation consists of helium nuclei and is readily stopped by a sheet of paper. Beta radiation, consisting of electrons or positrons, is halted by an aluminum plate. Gamma radiation is dampened by lead

Section 19. 3 Using the Nucleus as a Source of Energy E. Effects of Section 19. 3 Using the Nucleus as a Source of Energy E. Effects of Radiation Rem: the quantity of ionizing radiation whose biological effect is equal to that produced by one roentgen of x-rays. Roentgen is a defined amount of ionization of dry air

Section 19. 3 Using the Nucleus as a Source of Energy U. S. Nuclear Section 19. 3 Using the Nucleus as a Source of Energy U. S. Nuclear Regulatory Commission limit of 5, 000 mrem/year above background for nuclear industry workers

Section 19. 3 Using the Nucleus as a Source of Energy Section 19. 3 Using the Nucleus as a Source of Energy