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Chapter 4: Discovering the Secrets of the Nucleus From a Photographic Mystery to the Atomic Bomb © 2003 John Wiley and Sons Publishers Courtesy Fermilab/Peter.

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Presentation on theme: "Chapter 4: Discovering the Secrets of the Nucleus From a Photographic Mystery to the Atomic Bomb © 2003 John Wiley and Sons Publishers Courtesy Fermilab/Peter."— Presentation transcript:

1 Chapter 4: Discovering the Secrets of the Nucleus From a Photographic Mystery to the Atomic Bomb © 2003 John Wiley and Sons Publishers Courtesy Fermilab/Peter Arnold Inc.

2 Brain images with 123 I-labeled compound

3 Figure 4.1 © 2003 John Wiley and Sons Publishers

4 Antoine Henri Becquierel. © 2003 John Wiley and Sons Publishers Courtesy Culver Pictures, Inc.

5 Marie Sklodowska Curie with her daughter, Irene. © 2003 John Wiley and Sons Publishers Courtesy The Center for the History of Chemistry

6 Radioactive Isotopes A radioactive isotope has an unstable nucleus and emits radiation to become more stable. Isotopes of elements may be stable or unstable.

7 Alpha Decay When a radioactive nucleus emits an alpha particle, a new nucleus results. The mass number of the new nucleus is 4 less than that of the initial nucleus. The atomic number is decreased by 2.

8 Equation for Alpha Decay Write an equation for the alpha decay of Rn-222. 222 Rn new nucleus + 4 He 86 2  Determine the mass and atomic numbers of the new nucleus. Mass number: 222 – 4 = 218 Atomic number:86 – 2 = 84 Symbol of element 84 = Po  Complete the equation with the new symbol: 222 Rn 218 Po + 4 He 86 84 2

9 Beta Decay  A beta particle  Is an electron emitted from the nucleus.  Forms when a neutron in the nucleus breaks down. 1 n 0 e + 1 H 0 -1 1

10 Figure 4.5: Radioactive decay of tritium. © 2003 John Wiley and Sons Publishers

11 Figure 4.6: Radioactive decay of carbon-14. © 2003 John Wiley and Sons Publishers

12  Potassium - 42 is a beta emitter. 42 K new nucleus + 0 e 19 -1  The atomic number of the new nucleus increases by 1. Mass number : (same) = 42 Atomic number: 19 + 1 = 20 Symbol of element 20= Ca  The nuclear equation is 42 K 42 Ca + 0 e 19 20 -1 Writing An Equation for a Beta Emitter

13 Ernest Rutherford discovered α rays and β rays. © 2003 John Wiley and Sons Publishers Courtesy C.E. Wynn-Williams

14 Write the nuclear equation for the beta decay of Co-60. 60 Co 27 Learning Check

15 Write the nuclear equation for the beta decay of Co-60. 60 Co 60 Ni + 0 e 2728  1 beta particle Solution

16 Gamma radiation is energy emitted from an unstable nucleus indicated by m. In a nuclear equation for gamma emission, the mass number and the atomic number are the same. 99m Tc 99 Tc +  43 43 Gamma  Radiation

17 Summary of Radiation

18 Producing Radioactive Isotopes A nucleus is converted to a radioactive nucleus by bombarding it with a small particle.

19 What radioactive isotope is produced when a neutron bombards cobalt-59? 59 Co + 1 n ???? + 4 He 27 0 2 Learning Check

20 What radioactive isotope is produced when a neutron bombards cobalt-59? mass numbers = 60 = 60 59 Co + 1 n 56 Mn + 4 H e 27 0 25 2 = 27 = 27 atomic numbers Solution

21 Figure 4.2: The penetrating power of radiation. © 2003 John Wiley and Sons Publishers

22 Figure 4.3: Notation showing atomic number, mass number, and charge. © 2003 John Wiley and Sons Publishers

23 Gamma ray analysis of a fitting for a medical device shows it to be free of flaws. © 2003 John Wiley and Sons Publishers Courtesy Amersham Technology

24 Figure 4.4: The components of α rays, β rays, and γ rays. © 2003 John Wiley and Sons Publishers

25 Figure 4.7: The sequence of radioactive decay from 238-92U to 206-82Pb. © 2003 John Wiley and Sons Publishers

26 Figure 4.8: A typical fission reaction of U-235. © 2003 John Wiley and Sons Publishers

27 Nuclear Fission When a neutron bombards U-235, an unstable nucleus of U-236 undergoes fission (splits) to form smaller nuclei such as Kr-91 and Ba-142.

28 Chain Reaction  A chain reaction occurs when a critical mass of uranium undergoes fission so rapidly that the release of a large amount of heat and energy results in an atomic explosion.

29 Lise Meitner interpreted Otto Hahn’s experimental observations as confirmation that he had split a uranium nucleus. © 2003 John Wiley and Sons Publishers Courtesy Bibliothek Und Archiv zur Geschichte der Max-Planck-Gesellschaft, Berlin

30 Figure 4.10: Enrichment by gaseous diffusion. © 2003 John Wiley and Sons Publishers

31 Uranium-235, a source of nuclear power. © 2003 John Wiley and Sons Publishers Courtesy US Department of Energy

32 Figure 4.11: The operation of fission bombs. © 2003 John Wiley and Sons Publishers

33 The world’s first atomic explosion, July 16, 1945 at Alamogordo, New Mexico. © 2003 John Wiley and Sons Publishers Courtesy Scott Camazine/Photo Researchers

34 J. Robert Oppenheimer and Leslie Groves at the remains of the tower used in the test of the first atomic bomb. © 2003 John Wiley and Sons Publishers Courtesy Bettmann/Corbis Images

35 Remains of a building after the explosion of the uranium bomb at Hiroshima, August 6, 1945. © 2003 John Wiley and Sons Publishers Courtesy Shigeo Hayashi

36 A flare ejected from the surface of the sun. © 2003 John Wiley and Sons Publishers Courtesy NASA

37 Fusion involves the combination of small nuclei to form a larger nucleus. Nuclear Fusion

38 Indicate if each of the following is 1) nuclear fissionor 2) nuclear fusion ___ A. A nucleus splits. ___ B. Large amounts of energy are released. ___ C. Small nuclei form larger nuclei. ___ D. Hydrogen nuclei react. ___ E. Several neutrons are released. Learning Check

39 Indicate if each of the following is 1) nuclear fissionor 2) nuclear fusion 1 A. A nucleus splits. 1, 2 B. Large amounts of energy are released. 2 C. Small nuclei form larger nuclei. 2 D. Hydrogen nuclei react. 1 E. Several neutrons are released. Solution

40 Albert Einstein, he discovered the equation that relates mass and energy. © 2003 John Wiley and Sons Publishers Courtesy AP/Wide World Photos

41 Nuclear Power and Its Wastes Divan Fard This Way to Sustainability V Conference at California State University, Chico November 5-8, 2009

42 Acknowledgement Roy Gephart; Jim Amonette, Elsa Rodriguez, Jose Marquez (Pacific Northwest National Laboratory Richland, Washington USA) Department of Energy AAAS NRC IAEA Institute for Energy and Environmental Research American Nuclear Society Green Peace Physicians for Social Responsibility

43 What to read

44 Dr. Helen Caldicott’s message : “Every male in the Northern Hemisphere has a tiny load of plutonium in his testicles from nuclear (weapons) testing days,” Caldicott said, as men in the audience squirmed. March 24, 2011 8:45 p.m. http://www.metronews.ca/ottawa/business/article/813044--new-reactors-mean-more-cancer-critic

45 Wind, water and solar technologies can provide 100% of the world’s energy, eliminating all fossil fuels. Scientific American November 2009 Mark Z. Jacobson, Mark A. Delucchi http://www.scientificamerican.com/article.cfm?id=a-path-to-sustainable-energy-by-2030

46 Save 2.5 million to 3 million lives a year Halt global warming, Reduce air and water pollution Develop secure, reliable energy sources Nearly all with existing technology and at costs comparable with what we spend on energy today http://www.sciencedaily.com/releases/2011/01/110126091443.htm http://www.sciencedaily.com/releases/2011/01/110126091443.htm ScienceDaily (Jan. 27, 2011) why wouldn't you do it?

47 Key Concepts The authors’ plan calls for 3.8 million large wind turbines, 90,000 solar plants, and numerous geothermal, tidal and rooftop solar energy panels. The cost of generating and transmitting power would be less than the projected cost per kilowatt-hour for fossil fuel and nuclear power.

48 Nuclear Industry Global warming is a reality and fast action is needed. Nuclear industry sees opportunity to promote itself.

49 One pound of Uranium produces one million times more energy than one pound of coal. Claimed Economic Advantages

50 Emissions Free Nuclear energy annually prevents millions tons of sulfur millions tons of nitrogen oxide millions metric tons of carbon

51 Nuclear Fission 1934-Otto Hahn discover fission 1938– Scientists study Uranium nucleus

52 History of nuclear power 1934-Otto Hahn discover fission 1938– Scientists study Uranium nucleus 1941 – Manhattan Project begins 1942 – Controlled nuclear chain reaction discovere 1945 – U.S. uses two atomic bombs on Japan 1949 – Soviets develop atomic bomb 1952 – U.S. tests hydrogen bomb 1955 – First U.S. nuclear submarine

53 The legacy of Hiroshima August 6, 1945: city of Hiroshima the victim of the 1 st nuclear weapon 140,000 killed. August 9, 1945: Nagasaki the victim of the 2 nd nuclear weapon; 75,000 killed. Massive, systematic attacks on civilian populations becomes permissible means of waging war.

54 Concept of Half-Life

55 Decay Series

56 Types of Emissions

57 Units of Radioactivity Curie (Ci) = 3.7X10 10 disintegration /Second

58 Fuel rods are usually 4m long and 15cm in diameter

59 Nuclear Fuel Cycle Uranium mining and milling Conversion and enrichment Fuel rod fabrication POWER REACTOR Reprocessing, or Radioactive waste disposal

60

61 Uranium enrichment Uranium ore is 0.7 %U-235 –Fuel Rod: U-235 3% –Weapons grade: U-235 90% Enrichment needs CFC-114 CFC-114 is 10,000-20,000 times heat trapping than CO 2 The uranium enrichment plant in Paducah, Ky., and its sister facility in Ohio :have been by far the country's largest industrial emitters of a chemical that eats the Earth's protective ozone layer. More than 800,000 pounds of CFC-114 emitted in to atmosphere, in 1999. -- as another example of the hidden costs of nuclear power. CFC-114: 1,2-dichlorotetrafluoroethane

62 Types of Radioactive Waste Very low-level waste (VLLW): Radioactive waste that can be safely disposed of with ordinary refuse Low-level waste (LLW): Trash from routine operations, It does not usually require special handling, unless contaminated with alpha emitters. Intermediate (medium) level waste (ILW): Radioactive waste which has little heat output. These wastes usually require remote handling High-level waste (HLW): Comprise either spent fuel or the highly active wastes resulting from the first stage of fuel reprocessing. A high degree of isolation from the biosphere, is required

63 Composition of the Spent Fuel The spent nuclear fuel contains about 93% uranium (mostly U-238) about 1% plutonium less than 1% minor actinides (neptunium, americium, and curium) 5% fission products

64 Global Nuclear Wastes Typical reactor will generate 20 to 30 tons of high-level nuclear waste annually The global volume of spent fuel is,290,000 tons, and is growing by approximately 10,000 tons annually. Despite billion of dollars of investment in various disposal options, the nuclear industry and governments have failed to come up with a feasible and sustainable solution.

65 Radioactivity of plutonium Half life of plutonium (Pu-239) is 24000 years Life span of at least 240,000 years Neanderthal Man died out 30,000 years ago

66 U-238 decay chain (main branch) Uranium-238 (half-life: 4.46 billion years) alpha decay ==> Thorium-234 (half-life: 24.1 days) beta decay ==> Protactinium-234m half-life: 1.17 minutes) beta decay ==> Uranium-234 (half-life: 245,000 years) alpha decay ==> Thorium-230 (half-life: 75,400 years) alpha decay ==> Radium-226 (half-life: 1,600 years) alpha decay ==> Radon-222 (half-life: 3.82 days) ==> followed by radon decay products (polonium, bismuth, lead isotopes)

67 Thorium-232 Thorium-232 is, like U-238, has its own decay chain Dangerous decay products build up relatively quickly in Th-232 They are thorium-228, actinium-228 (a beta- emitter), radium-228, and radium-224 Radium-224 gives off radon-220 (which is similar to radon-222)

68 Repository capacity Three isotopes, which are linked through a decay process (Pu241, Am241, and Np237), are the major contributors to the estimated dose for releases from the repository, typically occurring between 100,000 and 1 million years, and also to the long-term heat generation that limits the amount of waste that can be placed in the repository

69 Nuclear Waste Generation, Pollution and Remediation at the Hanford Nuclear Reservation Divan Fard, Jim Amonette, Elsa Rodriguez, Jose Marquez and Roy Gephart

70 Hanford Today: Waste and Nuclear Materials Volume/galCuriesChemicals Tank Waste( 179) 54 million 200 million220,000 MT Solid Waste190, million 6 million65,000 MT Soil and 293 billion 1 million100,000 to 300,000 MT Groundwater Facilities1300 million 10 million ---- Nuclear Material*186,000200 million ---- * 2.5 million times the Nagasaki bomb Groundwater Waste tanks, ranging in size from 55000 to 1100000 gallons. Only 13 pounds of plutonium were used to destroy Nagasaki.

71 Drinking water mortality risks in millionth per Pico curie intake (Ref. value: Pu-239 = 2.85) U-238 decay chain (main risks) U-238: 1.13 U-234: 1.24 Th-230: 1.67 Ra-226: 7.17 Th-232 decay chain (main risks) Th-232: 1.87 Th-228: 1.82 Ra-228: 20.0 Ra-224: 2.74 Pico:10 −12 or 0.000000000001 www.ieer.org/comments/cotter.ppt

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74 Solid Waste 196 million gal of low-level and transuranic waste 6 million curies (1998) 360 kg of plutonium 580 MT of uranium Early YearsLater Years

75 Radio nuclide Releases to the Atmosphere 32M curies released 12M curies from reactors 20M curies from reprocessing plants Key Radionuclides Contributing to Dose (curies) Year I-131Ru-103/-106Ce-144Sr-90 Pu-239 1944-1949697,000 290 1740 30 2 1950-1959 43,000 1130 630 10 <1 1960-1969 460 130 1350 25 <1 1970-1972 <11 50 2 <1 99% of dose from I-1311% of dose from these radionuclides

76 History of Hanford Tank Waste 530 Million gal High-Level Waste Generated (1944-1988) Reprocessed 239,000 m 3 Disposed to Ground* 490,500 m 3 Leaked to Ground 3800 m 3 Evaporated 1.05 million m 3 53 million gal Remaining in Tanks (2000) *after radionuclide scavenging or cascading Started 1956 Started 1945 Started 1956 Started 1951

77 Ponds 1944-1990s Ponds, 1944-1990s

78 French Drains 1944-1980s French Drains 1944-1980s Reverse Wells, 1945 – 1955, (one to 1980)

79 Specific Retention Trenches 1944-1973

80 Cribs, 1944-1990s

81 Radioactive contaminants include: iodine-129, strontium-90, technetium-99, tritium, and uranium. Non-radioactive contaminants, chromium and chlorinated solvents. Remediation Techniques: Commonly sought Pump-and-treat method; Savannah river site In situ remediation Contaminants of Hanford Nuclear reservation groundwater:

82 History of U.S. Nuclear Waste Policy 1956: National Academy of Sciences concludes that a deep geologic repository is the best permanent solution for disposal of high-level nuclear wastes (HLW) 1977: Reprocessing of commercial spent nuclear fuel (SNF) is prohibited under President Carter 1982: Congress passes Nuclear Waste Policy Act (NWPA) –Made DOE responsible for the permanent disposal of U.S.’s SNF and HLW –Created Office of Civilian Radioactive Waste Management in DOE –Set up program to begin investigation of sites as potential geologic repositories and established site recommendation/approval process –Established Nuclear Waste Fund, and directed DOE to begin accepting commercial spent fuel for disposal in 1998 in exchange for utilities’ payment of fees into the fund

83

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85 24 years

86 Why Yucca Mountain? Yucca mountain

87 Repository Reference Design Concept Repository Concept N Waste Handling Building Waste Treatment Building Transporter Maintenance Building Surface Layout Waste Receiving North Portal Entrance Alcove #1 Enhanced Characterization Repository Block Drift Subsurface Layout Waste Emplacement To accommodate 70,000 metric tons, the proposed repository would include approximately 36 miles of tunnels which would hold approximately 10,000 waste packages.

88 Repository Program Schedule ActivityDate Submited Yucca Mt. License Application to NRC Feb 19, 2009 Begin Nevada rail construction (Caliente route,”) http://www.rgj.com/article/20090411/NEWS/904110320/1321 Oct. 2009 NRC authorizes repository construction Sept. 2011 Complete initial rail access Jun. 2014 Complete construction for initial repository operations Mar. 2016 Begin receipt of Nuclear Wastes Mar. 2017

89 How will Spend Nuclear Wastes and High Level Waste be Transported? Per 2004 Record of Decision, DOE will transport SNF and HLW mostly by rail, with additional limited truck and barge shipments

90 Drinking water mortality risks in millionth per Pico curie intake (Ref. value: Pu-239 = 2.85) U-238 decay chain (main risks) U-238: 1.13 U-234: 1.24 Th-230: 1.67 Ra-226: 7.17 Th-232 decay chain (main risks) Th-232: 1.87 Th-228: 1.82 Ra-228: 20.0 Ra-224: 2.74 Pico:10 −12 or 0.000000000001

91 April 26, 1986, Chernobyl disaster

92 3.5 million sick, one/third of them children Chernobyl 4,000 deaths in 20 years 4056 ( 03/24/11)

93 400 million people exposed in 20 countries

94 Health effects radiation exposure: -increased likelihood of cancer -birth defects including long limbs, -braindamage -conjoined stillborn twins -reduced immunity -genetic damage

95 Melt Down, Three-Mile Island PA 1979

96 Health around TMI In 1979, hundreds of people reported nausea, vomiting, hair loss, and skin rashes. Many pets were reported dead or showed signs of radiation Lung cancer, and leukemia rates increased 2 to 10 times in areas within 10 miles downwind Farmers received severe monetary losses due to deformities in livestock and crops after the disaster that are still occurring today.

97 Plants near TMI -lack of chlorophyll -deformed leaf patterns -thick, flat, hollow stems -missing reproductive parts -abnormally large leaf size TMI dandelion leaf at right

98 Animals Nearby TMI Many insects disappeared for years. –Bumble bees, carpenter bees, certain type caterpillars, or daddy-long-leg spiders –Pheasants and hop toads have disappeared.

99 Other reactor accidents (besides TMI and Chernobyl) 1952 Chalk River, Ontario –Partial core meltdown 1957 Windscale, England –Graphite reactor fire contaminates 200 square miles. 1975 Browns Ferry, Alabama –Plant caught fire 1976 Lubmin, East Germany –Near meltdown of reactor core. 1999 Tokaimura, Japan –Nuclear fuel plant spewed high levels of radioactive gas –March 11, 2011 Fukushima Daiichi Nuclear Accident

100 Sustainable Energy Alternatives Bioenergy: biomass, such as plant matter and animal waste, can yield power, heat, steam, and fuel. Geothermal: renewable heat energy can be harnessed from deep within the earth.Geothermal Wind: turbines turning in the air convert kinetic energy in the wind into electricity. Solar: the sun’s energy can be captured and used to produce heat and electricity.

101 Hydrogen: if produced by renewable sources, it can power fuel cells to convert chemical energy directly into electricity, with useful heat and water as the only byproducts. Tidal: using the movement of the ocean to power turbines and generate electricity.

102 End

103 © 2003 John Wiley and Sons Publishers What incorrect assumption did Becquerel make in beginning his investigation of uranium, sunlight, and photographic paper? What correct conclusion did he reach when he found spots on paper that was in contact with uranium exposed to the sun? What incorrect conclusion did he reach when he made this observation? What result caused him to turn the entire project over to Marie Sklodowska Curie for further investigation? QUESTION

104 © 2003 John Wiley and Sons Publishers Which component of radioactivity would be stopped by this single page? Which two components would be stopped (completely or almost completely) by this entire book? Which component would pass, almost undiminished, through both this single page and this entire book? QUESTION

105 © 2003 John Wiley and Sons Publishers How does an atom’s atomic number change when its nucleus loses a(n): (a) α particle, (b) β particle, (c)  ray? How does that atom’s mass number change with the loss of each of these? QUESTION

106 © 2003 John Wiley and Sons Publishers In what ways does the structure of an atom of antihydrogen differ from the structure of an atom of hydrogen? In what ways are the two atoms similar? QUESTION

107 © 2003 John Wiley and Sons Publishers When an atom of uranium –235 is bombarded with neutrons, one of the many fission reactions it can undergo produces barium and an additional element (as well as energy and additional neutrons) but no α particles or β particles. With this in mind, and with reference to the periodic table, name the additional element produced in this particular mode of fission. QUESTION

108 © 2003 John Wiley and Sons Publishers (a) What is the advantage to using U-235 rather than U-238 as the fissionable material in building a fission bomb? (b) What is the disadvantage to using U-235 rather than U-238 as the fissionable material? QUESTION

109 © 2003 John Wiley and Sons Publishers How was a critical mass achieved in the detonation of the U-235 bomb? In the detonation of the Pu-239 bomb? QUESTION

110 © 2003 John Wiley and Sons Publishers Using the Law of Conservation of Mass and the Law of Conservation of Energy, show why nuclear fission might not be viewed as a chemical reaction. QUESTION

111 © 2003 John Wiley and Sons Publishers Calculate the mass defect of an atom of Pu- 239. The measured mass of an atom of Pu-239 is 239.05 amu. QUESTION

112 © 2003 John Wiley and Sons Publishers Table 4.2 shows that the efficient burning of 1g of gasoline could keep a 100-watt light bulb burning for 8 minutes. How long would the energy obtained by the complete conversion of the gram of gasoline directly into energy keep the bulb lit? QUESTION


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