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Topics for Today Ionizing Radiation and Human Health –Finish up Nuclear Fission –The 1 st wartime atomic bomb –Cell Damage –Radiation Sickness.

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Presentation on theme: "Topics for Today Ionizing Radiation and Human Health –Finish up Nuclear Fission –The 1 st wartime atomic bomb –Cell Damage –Radiation Sickness."— Presentation transcript:

1 Topics for Today Ionizing Radiation and Human Health –Finish up Nuclear Fission –The 1 st wartime atomic bomb –Cell Damage –Radiation Sickness

2 Readings for Today Hazards Associated with Radioactivity Section 7.8 The DNA double Helix Section12.2

3 Topics for Friday –Radiation Sickness –Natural sources of radiation –Quiz #3

4 Readings for Friday Hazards Associated with Radioactivity Section 7.8

5 Announcements

6 Radon Disks! Are they in place? Are they still there?

7 Exam #1 NEXT Friday!

8 Exams will be “multi-formatted” Multiple Choice! Problems! Concept Questions!

9 Exams will be handed out as you enter the door You will have until the end of the period to complete the exam

10 Exams will be handed out as you enter the door You will have until the end of the period to complete the exam I will be there starting at the beginning of the passing period, 8:35.

11 As with quizzes… Non-memory calculators are OK Please sit in dark colored seats

12 Topics for Today Ionizing Radiation and Human Health –Finish Monday’s material –The 1 st wartime atomic bomb –Cell Damage –Radiation Sickness

13 Monday Review! Nuclear Fission…

14 What’s in the Cloud? Water Along with a lot earth, we find “fallout” What about the fission products from a power plant?

15 Each cylinder contains 14 TONS of nuclear waste. This waste is called “spent nuclear fuel” or (SNF).

16 These barrels contain fission byproducts, unfissioned U-235 and lots of U-238 and Pu-239. Where did Pu-239 come from?

17 Remember, U-235 is only 3-5% of the uranium in a nuclear power plant.

18 From Monday… Remember, U-235 is only 3-5% of the uranium in a nuclear power plant. The rest of the uranium is mainly U-238!

19 Review - Monday What happens when a neutron hits U-238?

20 UU n [ [ U [ [ Np + + β Np Pu+ β t 1/2 = 2.4 days t 1/2 = 24,100 years Is Pu-239 fissionabl e?

21 UU n [ [ U [ [ Np + + β Np Pu+ β t 1/2 = 2.4 days t 1/2 = 24,100 years Is Pu-239 fissionabl e? Can current nuclear power plants use Pu- 239 for energy?

22 A “standard” nuclear reactor does not produce too much Pu-239.

23 Breeder Reactor… Simultaneously creates energy from U-235 and enriches the new fissionable fuel (Pu- 239) from U-238. CREATES more fissile fuel than we started with!!

24 These barrels contain fission byproducts, unfissioned U-235, lots of U-238, and some Pu-239. Breeder reactors DRASTICALLY cut down on the amount of nuclear waste…

25 The technology is here; do we use them?

26 We used to use them (1950s up to 1977).

27 For fear of terrorists stealing the enriched nuclear fuel, President Carter banned the reprocessing of depleted fuels (1977).

28 Likely linked to the Cold War politics.

29 And with current political conditions…

30 This is what we are left with…

31 There are currently over 100 nuclear power plants in the US

32 Which state has the most nuclear reactors? There are currently over 100 nuclear power plants in the US

33 NOTE: No nuclear power plants in Alaska or Hawaii.

34 How much fuel is needed?

35 In 2005, Wisconsin used 24.6 THOUSAND TONS of coal for energy production.

36 How much fuel is needed? In 2005, Wisconsin used 24.6 THOUSAND TONS of coal for energy production. That’s 49,200,000 lbs of coal!!

37 How much fuel is needed? How much uranium would be needed for the same energy output in WI?

38 For every 1 pound of uranium fuel, you need to burn about 18,400 pounds of coal to get the same energy output. WI burned 49,200,000 lbs of coal in 2005 This would be 2,700 lbs of uranium annually in WI

39 Topics for Today Ionizing Radiation and Human Health –The 1 st wartime atomic bomb –Cell Damage –Radiation Sickness

40 HIROSHIMA First wartime atomic bomb blast August 6, 1945

41 Hiroshima was a city at work. The streets were filled. Children had reported to schools; it was a time when direct exposure in the open was at its peak…then, at 8:14 AM a prolonged and brilliant flash. Accompanying the flash of light was an instantaneous flash of heat traveling with the speed of light…duration probably less than one-tenth of a second, and its intensity sufficient to cause nearby things to burst into flames as far as four thousand yards from the hypocenter, with temperatures exceeding 1800 degrees Celsius…then a shock wave (Liebow 24).

42 Initial Blast 1945 Population of Hiroshima = 300,000 About 100,000 people were killed Nearly every structure within one mile of ground zero was destroyed

43 US Dept of Energy

44 Within minutes after the blast, 9 out of 10 people half a mile or less from ground zero were dead. US Dept of Energy Of those who did survive….

45 Several days after the blast, medical staff began to recognize the first symptoms of radiation sickness among the survivors Deaths from radiation sickness did not peak until three to four weeks after the attacks An estimated 30,000 extra deaths occurred within 4 months of the blast. “The pain of war can not exceed the woe of aftermath”

46 Radiation Sickness “...survivors developed symptoms that puzzled doctors, such as blood cell abnormalities, high fevers, chronic fatigue, diarrhea, vomiting, hair loss, and depression.” “Years later doctors noticed an increase in the incidence of cancer among the survivors...” US Dept of Energy

47 3 days after Hiroshima… Second wartime atomic bomb blast Nagasaki, Japan August 9, 1945

48 Video This video was taken shortly after the bomb blast in Hiroshima…

49 Video This video was taken shortly after the bomb blast in Hiroshima… Full-length Video

50 After Hiroshima When asked how he thought WWIII would be fought, Einstein replied

51 After Hiroshima When asked how he thought WWIII would be fought, Einstein replied “I don’t know how WWIII will be fought, but WWIV will be fought with sticks and stones.”

52 Why did the symptoms of radiation sickness take 1-2 weeks to manifest?

53 What was in the “black rain”? Akijiro Yashima 3,700 m from the hypocenter

54 Review – Nuclear Fallout What is nuclear fallout? What is nuclear fallout composed of? Is it radioactiv e? How does radioactivity affect people? Is anyone IMMUNE to the effects of radioactivity?

55 Review – Nuclear Fallout What is nuclear fallout? What is nuclear fallout composed of? Is it radioactiv e? How does radioactivity affect people? Is anyone IMMUNE to the effects of radioactivity?

56 H2OH2O Ionizing radiation (alpha, beta, or gamma) REVIEW Why water?

57 1.Water can range from % of your body mass 1.Depends on your sex and body structure 2.Gamma rays are more likely to interact with water molecules than fats, lipid, proteins, etc…

58 H2OH2O electron

59 H2OH2O H2OH2O + + Ionizing radiation + e-e-

60 In other words, H 2 O H 2 O.+ + e – Ionizing radiation

61 In other words, H 2 O H 2 O.+ + e – Ionizing radiation What does the. mean?

62 In other words, H 2 O H 2 O.+ + e – Ionizing radiation What does the. mean? H 2 O.+ is a free radical

63 A free radical is any atom or molecule or ion with an unpaired electron.

64 Free radicals (as we will soon see) are often VERY reactive.

65 We left off here H 2 O H 2 O.+ + e – Ionizing radiation

66 We left off here H 2 O H 2 O.+ + e – Ionizing radiation What will H 2 O.+ most likely react with?

67 We left off here H 2 O H 2 O.+ + e – Ionizing radiation What will H2O.+ most likely react with?

68 .+.+ DNA Inside a Cell

69 H 2 O H 2 O.+ + e – Ionizing radiation What will H 2 O.+ most likely react with? Another water molecule! H 2 O.+ + H 2 O. OH + H 3 O + Unpaired electron

70 H 2 O H 2 O.+ + e – Ionizing radiation This happens within FRACTIONS of a second H2O.+ + H 2 O. OH + H 3 O + Unpaired electron

71 CAUTION

72 Are these chemical reactions or nuclear reactions?

73 H 2 O H 2 O.+ + e – Ionizing radiation This happens within FRACTIONS of a second H2O.+ + H 2 O. OH + H 3 O + Unpaired electron

74 Another free radical…. OH is the hydroxyl radical. OH will react with just about anything.

75 Another free radical…. OH is the hydroxyl radical. OH will react with just about anything.. OH does not discriminate between molecules

76 Figure 12.8 Including our DNA


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