n Discovery of the atom n n n

n Discovery of the atom n n n Electron Orbit energy levels – a quantum n n n Fluorescence, black lights LASERS The Nucleus n n n Parts of the atom Bohr Atom Mass has energy: E=mc 2 Debate over the age of the earth Nuclear Energy n Nuclear Power Plants n n n n How they work Typical Capacity The costs The future Diablo Canyon – Avila Beach 3 -mile Island Chernobyl Nuclear Submarines

How are electricity demands managed? n n n Satisfy base-loads with cheapest sources of power to operate Turn on and off sources that are easy to switch on and off to meet peak demands. Power Grid is one big circuit with suppliers of electrical power providing power and loads (cities and factories) which take power from the grid.

http: //currentenergy. lbl. gov/ca/index. php

http: //www. flexibleenergy. com

Photosynthesis consumes CO 2 while combustion of hydrocarbons produces CO 2 (Ethane) 2 C 2 H 6 + 7 O 2 4 CO 2 + 6 H 2 O (Propane) C 3 H 8 + 5 O 2 3 CO 2 + 4 H 2 O (Wood/sugar)C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O (gas) 1 C 7 H 16 + 22 O 2 7 CO 2 + 8 H 20

Carbon Cycle n n Burning takes in Oxygen and produces carbon by -products Fossil fuels are 100, 000 -year energy deposits that have transformed into energy sources with high energy density Burning fossil fuels releases carbon over a short time that took millions of years to build up. We produce more carbon than is consumed, therefore the carbon cycle is not in balance

CO 2 is a greenhouse gas Greenhouse gases are: water vapor carbon dioxide methane ozone nitrous oxide

How CO 2 contributes to atmospheric temperature n n n Mercury Venus Earth d = 0. 4 AU d = 0. 72 AU d = 1 AU T = -279 800 0 F No atmosphere T = 867 0 F CO 2 = 96% T = 59 0 F CO 2 = 0. 037%

CO 2 levels are rising Keeling Curve:

Earth’s temperatures are rising

Driving in Stabilization Wedges to reduce the release of carbon into the atmosphere http: //www. princeton. edu/~cmi/resources/CMI_Resources_new _files/CMI_Wedge_Game_Jan_2007. pdf

Replace CO 2 producing technologies with other technologies n n n Electing to use power sources that do not produce CO 2 Finding renewable fuel sources that consume carbon when produced Shift towards incentives for using technologies that are eco-gentle and low on greenhouse gas output Work with Japan, Europe, and other proactive nations to create global standards and consequences Sign UN’s International Treaty (Kyoto) to stabilize greenhouse gas emissions.

Nuclear Power – Can it help stabilize greenhouse gas emissions? n n The Atom Obtaining a Fuel source Process of getting power from Nuclear Fuel History n n n Safety n n n Chernobyl Three Mile Island Diablo Canyon Palo Verde Success: France and Canada Yucca Mountain True Costs Opportunities and Challenges today

www. solcomhouse. com

n n n A nucleus has protons and neutrons Elements are identified by the number of protons in their nucleus Protons have a charge of +1 Electrons orbit the nucleus Electrons – negatively charged The Nucleus doesn’t break apart because there is a strong force holding the protons together. The Atom http: //www. cfo. doe. gov

Periodic Table n n Each element has a unique number or protons The column location of an element indicates the arrangement of the outer electrons and how that element bonds with other elements

Electrons are confined to certain orbits. When electrons move from outer to an inner orbit, a packet of electromagnetic energy is emitted. This packet is called a photon. www. tulane. edu

n n n An atom’s diameter is roughly 100, 000 times bigger than its nucleus Atom is mostly empty space The mass of a proton or neutron is 2000 times the mass of an electron Nucleus is VERY tightly packed with protons and neutrons Nucleus gives atom its mass and electrons give atom its size and bonding behavior Chemistry is what happens at the electron level.

Fluorescence – an example of what happens when electrons move between energy levels n n When an object gives off light even when it is not hot Object absorbs Ultraviolet Light (non visible) and emits visible light Ex. “black light” gives off UV light. The fluorescent object absorbs this light, and an electron is raised to a higher energy level. When the electron falls back to a lower energy state, a photon in the visible spectrum is emitted.

Fluorescent Colors Neon Lights

Fluorescent Lights, TV screens, “glow in the dark”, etc. all contain Phosphors n n n Phosphors radiate visible light when energized Energized mercury atoms emit invisible UV Phosphor atoms are themselves energized by the UV photon When phosphor electrons jump to lower energy states, photons in the visible spectrum are emitted These electron Jumps are called quantum leaps

Most Elements are Stable n n Elements may react with other elements and be involved in chemical reactions but the majority of elements do not change into other elements. Chemistry deals with what is happening with the electrons – chemical bonding has no effect on the nucleus

Combustion – a chemical reaction where elements and electrons are rearranged + Heat, light, particulates, ashes CH 2 O + O 2 CO 2 + H 2 O BUT we have the same elements on both sides of the reaction.

Through Einstein’s work on relativity he found that mass is a form of energy E = mc 2 n n n E – energy m – mass c = 186, 000 miles/second (speed of light)

Everyday changes in Mass n n n With common, everyday chemical reactions, when energy is given off in a reaction, a tiny bit of mass is lost When objects are energized, a tiny bit of mass is gained These changes in mass are insignificant

What if 20% of a nucleus’ mass was converted to energy? n n n E = mc 2 Mass = E/c 2 It would take 0. 004 grams of mass to provide annual energy used by one American (10, 000 KWH)

Radioactive Elements n n n Elements that spontaneously decay into other elements Radioactive elements give off radiation Radiation can be electromagnetic waves and/or energetic particles with mass

How are electromagnetic waves produced? n n Produced from the motion of charged particles Accelerating charge produces a magnetic field A changing magnetic field produces an electric field (measured in voltage) A changing electric field produces a magnetic field, and so on…

Electromagnetic Spectrum

Radioactive Decay n n n Random process Mass is lost during decay E = mc 2 Mass is converted into energy It is a nuclear reaction not a chemical reaction (it is the nucleus that is getting rearranged not the electrons) The “parent” element turns into a “daughter element of less mass

Radioactive Radiation Alpha particles are Helium Atoms. Alpha particles gain kinetic energy from the mass of the “parent” atom Beta particles are electrons. Being of low mass, they penetrate deeper into objects but they can be stopped with a metal shield. Gamma Rays are high energy electromagnetic radiation. They have no mass. When charged particles are accelerated in the nucleus an electromagnetic wave is produced. This radiation is the most penetrating. Wikipedia

Alpha Particle http: //web. princeton. edu

Decays to Thorium

Beta Particle A neutron is converted into a proton, an electron, and a neutrino. The parent has an excess of neutrons. A neutrino has no charge and negligible mass.

Gamma Radiation after Beta Decay Produced when nucleus is rearranged Daughter nucleus is in an excited state. When the nucleus drops to a lower energy state gamma radiation is emitted.

Some E&M waves are ionizing

Ionizing and non-Ionizing Radiation Non-ionizing radiation does not have enough energy to ionize atoms. Ionizing radiation (particles or waves) has enough energy to knock an electron out of its orbit. This is usually harmful to living things because the atom can not longer bond in its normal way. This can effect cells and DNA.

Nuclear Reactions: n n Fusion Fission

Fission Reaction – the splitting of atoms n n Hiroshima Nagasaki 220, 000 died from explosions Many Casualties due to radiation exposure http: //en. wikipedia. org/wiki Nagasaki before and after

Fusion n The fusing of elements to form a heavier element n n The heat produced keeps the fusion going 1% of mass is lost in reaction The sun loses million tons of mass every second. http: //www. astronomy. com

First human-made Fusion reaction n n Hydrogen Bomb A Fission reaction produces the intense heat necessary to initiate the fusion reaction More powerful than fission bomb Not used in warfare but tested in 1952 north-east of Australia in the Marshall Islands Bikini Island uninhabitable http: //library. thinkquest. org

Fission Nuclear Reactor www. euron uclear. org

Thermal Energy Electricity Fission Products vary www. zamandayolculuk. com A neutron hits a Uranium-235 atom. U-235 splits into two equal size nuclei which in turn release neutrons. These neutrons will then bombard other U-235 atoms, thus starting a chain reaction.

Chain Reaction http: //www. youtube. com/watch? v=Jxz. PNvd. P_0&feature=related

Uranium 235 n n 0. 7% of all Uranium exists as this isotope Fuel pellets are enriched – 3% U-235 Uranium is extracted through chemical leaching http: //en. wikipedia. org Enriched fuel pellets

What is an isotope? n Different forms of the same element, each having a different atomic weight (different number of neutrons) 1% of carbon is Carbon-13 n 0. 0001% of carbon is Carbon-14 with a half life of 5700 years n After 5700 years, a dead object will have half of the Carbon-14 it started with n

Obtaining Fuel Pit or underground mines Moab, UT

Components of a Nuclear Power Plant 1. 2. 3. 4. The Fuel Core The Control System Steam turbine and generator Cooling System

Fuel Core n n Fuel pellets are put in Zirconium alloy rods to seal the radiation 200 -300 rods are bundled into assemblies 100 -200 assemblies are used in a reactor During reaction neutrons can move between fuel rods http: //www. oncor. com

http: //www. npp. hu

Control System Trojan Nuclear Power Plant, Oregon Demolished in 2006

Cooling

Diablo Canyon – San Luis Obisbo Concrete steel reinforced containments 2240 MWatts http: //cache. eb. com

Diablo Canyon n n n PG&E plans for plant in 1968 Plant comes on line in 1984 -1985 Plant costs $5. 8 billion Costs are 18 times original projections Major licensing problems due to public’s negative reaction and proximity to fault lines PG&E has major financial set-backs from the project 30 year license

Palo Verde Nuclear Generating Station n 3200 MWatts Serves 4, 000 people Largest Nuclear Power plant in the US NRC

3 -Mile Island – partial meltdown in 1979 with no release of radioactive material www. fda. gov

3 -mile Island sequence of events: 1. Feed Pump failed 2. Steam Generator got hot and so control rods were lowered into the reactor. 3. Reactor heated up and so the Pressurizer release valve opened. 4. Temperature in reactor dropped but release valve was “stuck” open. 5. The indicator light showed that the valve was closed. 6. Emergency feed pump would not operate 7. Reactor heats up as water in reactor has escaped. 8. Water was sent to the reactor but indicators showed there was water in the reactor so operators turned off entering water supply. 9. Fuel started to melt as no water is in the reactor, only steam. 10. Pressurizer release valve is discovered open and is then shut. 11. Water is fed into the reactor 12. 60% of core melted 13. Radiation is contained within the containment building

Multiple problems occur simultaneously resulting in disaster

Chernobyl, Ukraine n n n 1986 Worst nuclear power reactor disaster in history Explosion of containment structure Wikipedia

Nuclear Fuel enrichment and Nuclear power is complex with multiple steps and many safeguards that must not fail

Other Challenges n n n Costly to construct Radioactive waste must be stored Complexity leads to centralized power production Mistakes may be lethal Potential National Security Target Expensive to update or dismantle

Worth the effort and risk? n n n 0. 35 milligrams of fuel produces 8700 KWH of energy This is enough energy to power about 100 homes every month No CO 2 emissions Expensive form of power Waste remains radioactive for many years

Discarding Nuclear Waste n n n Yucca Mountain, Nevada East of Death Valley Scheduled to open 2017 Majority of Nevadans against facility 15% of Nevadans get electricity from Palo Verde Nuclear Power Plant in AZ (Why don’t they elect a green source? )

http: //en. wikipedia. org

Learning from the past before hailing nuclear power as a savior to the Global Warming problem n n What have we learned? Considering fuel processing, capital outlay for plant construction, waste storage, and maintenance, is this really an inexpensive form of electricity?

France has 59 Nuclear Reactors Smaller (1000 MWatts) and more distributed plants.

Nuclear Submarines n n In use since 1950’s Nuclear Power Plant on sub is shielded with steel and water. http: //www. fcnl. org

Smoke Detectors Contains a source of ionizing radiation – alpha particles

n n n Alpha particles ionize the air Smoke particles attach to the ions and neutralizes them The electrical current in the chamber drops How. Stuff. Works

New Fuel sources: Opportunities to lead Solar 1. a) b) Wind Power Nuclear Power Cleaner Coal – how clean is it and how to sequester CO 2? Making waste into energy - Biomass Reducing demand through cultural changes and greater efficiencies Hydrogen and Fuel Cells Flex Fuels (biodiesel, ethanol) Batteries used in Electric and Hybrid Vehicles 2. 3. 4. 5. 6. 7. 8. 9. a) b) c) 10. How much energy do we get from the sun? How efficient is it to convert light or heat energy into other forms? Prius GM’s Electric Car or similar Tesla Motors The export of new energy saving products to countries