Chapter 9: Nuclear Chemistry

1. Chapter 9: Nuclear Chemistry • Radioactivity • Nuclear Equations • Radiation Detection • Half-Life • Medical Applications • Fission & Fusion

2. - - - + + + Isotopes of Hydrogen • Isotopes = Atoms of the same element but having different masses. 1 1 2 1 3 1 H H H Protium 99.99% Tritium Trace % Deuterium 0.01% Average Atomic weight of Hydrogen = 1.00794amu

3. 12 13 14 C C C 6 6 6 - - - - - - + + + - + + + + + + + + + - - + + + + + + - - - - - - - Isotopes of Carbon - - 98.89% 1.11% Trace % Average Atomic weight of C= 12.011amu

4. 14 3 1 C H 6 - - + + + + + - + + - - Radioactive Isotopes - - Hydrogen-3 Carbon-14 Nucleus is unstable So falls apart (decays) Giving radioactive particles

5. 123 53 131 53 I I 60 27 Co 99m Tc 43 Radioactive Isotopes in Medicine Diagnose thyroid function Treat hyperthyroid (destroys cells) Destroy tumors (g radiation) Diagnose bone, tissue (most common)

6. 210 84 210 84 206 206 Pb Pb Po Po 82 82 + + + + + + + + 4 2 4 2 He He Alpha Decay a Particle +

7. 14 6 14 - N C 7 + + + + + + + + 1 1 1 0 0 -1 0 -1 + e n H e + + + + Beta Decay b Particle + - + neutron proton electron

8. 14 6 14 6 14 14 - N N C C 7 7 + + + + + + + + 0 -1 0 -1 + e e + + + + Beta Decay b Particle + - +

9. 99m 43 99m 43 99 43 99 Tc Tc Tc Tc 43 + + + + + + + + + + + + Gamma Decay g decay g +

10. - Ionizing Radiation Radiation knocks off an electron An ion A radical Ions & radicals cause damaging chain reactions

11. - Geiger Counter Radiation knocks off an electron An ion Gas in instrument tube Ions detected by Counter

13. - + + Radiation: Penetration through Air a 4 cm b 6-300 cm 400 m g

14. - + + Tissue Penetration Depth a 0.05 mm 0.06-5 mm b >50 cm g

15. - + + Radiation: Shielding Heavy Cloth a Pb, thick concrete Paper Cloth b g

16. 4 2 4 2 He He Nuclear Equations a: Radon gas in Buildings 226 88 222 Rn + Ra 86 Gas 218 Po + 84 Cancer

17. 60 27 Co 0 -1 0 -1 e e 131 53 I Nuclear Equations b: Cancer Treatment 60 Ni + 28 b: Thyroid check & treatment 131 Xe + 54

18. Radiation Detection Activity # of disintegrations by of 1g Ra Curie (Ci): 1 Ci = 3.7 x 1010disintegrations sec Becquerel (Bq) 1 Bq = 1 disintegration sec

19. Radiation Detection Absorbed Dose

20. Tissue Penetration Depth - a 0.05 mm 0.06-5 mm b + + >50 cm g Radiation Detection: Biological Effect Radiation Absorbed Dose (Rad) (D): 1 rad = 1 x 10-2J kg tissue 1 rad = 2.4 x 10-3 cal kg tissue

21. - + + Tissue Penetration Depth a 0.05 mm 0.06-5 mm b >50 cm g Radiation Absorbed Dose (Rad) (D): 1 Gray = 1 J kg tissue 100 rad = 1 Gray

22. Radiation Detection Biological Damage

23. Radiation Equivalent for Man (rem) RBE 20 1 1 a b g 1 Rem = 1 Rad x RBE relative biological effectiveness

24. Annual Radiation Exposure in USA Total = 170 mrem / yr Cosmic = 40 mrem Air, H2O, Food = 30 mrem X-rays: Chest = 50 mrem Dental = 20 Smoking = 35 mrem TV = 2 mrem Radon = 200 mrem Wood,concrete,bricks = 50 mrem Ground = 15 mrem

25. Biological Effects of Radiation Dose in rem (at one time) 0-25genetic damage possible but usually undetected 25-100 decrease # of white blood cells (temporary) 100-200 mild radiation sickness (vomit, diarrhea, strong decrease # white blood cells) >300 (diarrhea, hair loss, infection) 500 LD50 for humans

26. Biological Effects of Radiation Dose in rem 300 LD50 for dogs 800 LD50 for rats 50,000 LD50 for Bacterium 100,000 LD50 for Insects 500 LD50 for humans

27. Therapeutic Doses of Radiation Dose in rem 4,500 Lymphoma 5,000 – 6,000 Skin cancer 6,000 Lung cancer 6,000 – 7000 Brain Tumor

28. FDA approved killing of bacteria with: 0.3 – 1 kGy ionizing radiation from Co-60 or Cs-137 (gamma producers) Strawberries left on counter for 2 weeks. The irradiated berries on right show no spoilage.

29. 131 53 I Half-Life t1/2 = Time for 1/2 sample to decay t1/2 = 8 days 8 days 5 g 10 g 20 g

30. Positron Emission Tomography (PET) 0 -1 0 +1 e e 11 6 - + C + + + 0 + + + + + 11 + B 0 5 + + 11 5 0 +1 e B electron 2g rays b+ Positron Detectable g rays  image Shows blood flow 11 6 C + positron

31. PET Scans Normal Alzheimer's

33. Known in Britain by the trade name ‘Pedoscope’. The machine produced an X-ray of the customer’s foot inside a shoe to ensure shoes fitted accurately, which both increased the wear-time of the shoe and with that, the reputation of the shoe shop. • The customer placed their foot over an X-ray tube contained within the wooden base of the Pedoscope. From this, a beam of X-rays passed through the foot and cast an image onto a fluorescent screen above. The screen could be observed via three viewing points – one for the shoe-fitter, one for the customer, and one for a third party (usually the guardian of a child being fitted). The accommodation for three viewing points may seem a little extravagant, but it may be an indication of the popularity of the Pedoscope and the interest the public had in the machine.

35. Shoe-Fitting Fluoroscope (ca. 1930-1940)

37. 91 36 Kr 235 92 236 92 1 0 U U n 142 56 Ba Fission Splitting atoms for Energy Energy + unstable • Uses: • Atomic Bomb • Nuclear Power

38. Fission Need critical mass of U-235 to sustain chain reaction to produce enough Energy for an explosion

39. Fission U-235 • Nuclear Power plants: • Controlled fission • avoids critical mass

40. Uranium oxide pellet used in nuclear fuel rods. Uranium is the fuel of the nuclear power plant in the US.  However, we can not just dump uranium into the core like we shovel coal into a furnace.  The uranium must be processed and formed into fuel pellets, which are about the size of a pencil eraser.  The fuel pellets are then stacked inside hollow metal tubes to form fuel rods.  Fuel rods are 11 to 25 feet in length.  Each UO2 pellet has the energy equivalent to burning 136 gal of oil, 2.5 tons of wood, or 1 ton of coal.

43. Trojan Nuclear Power Plant – Rainier, Oregon 46

44. May 21, 2006

45. Trojan Nuclear Reactor– Rainier, Oregon 48

46. Uranium oxide pellet used in nuclear fuel rods. Uranium is the fuel of the nuclear power plant in the US.  However, we can not just dump uranium into the core like we shovel coal into a furnace.  The uranium must be processed and formed into fuel pellets, which are about the size of a pencil eraser.  The fuel pellets are then stacked inside hollow metal tubes to form fuel rods.  Fuel rods are 11 to 25 feet in length.  Each UO2 pellet has the energy equivalent to burning 136 gal of oil, 2.5 tons of wood, or 1 ton of coal.

47. Yucca Mountain in Nevada – site for nuclear depository?

48. Conceptual Design of Yucca Mountain Disposal Plan • Canisters of waste, sealed in special casks, are shipped to the site by truck or train. • Shipping casks are removed, and the inner tube with the waste is placed in a steel, multilayered storage container. • An automated system sends storage containers underground to the tunnels. • Containers are stored along the tunnels, on their side.

50. Pros Department of Energy (DOE) • In a desert location • Isolated away from population centers (Las Vegas, the nearest metropolitan area, is 90 miles away) • Secured 1,000 feet under the surface • In a closed hydrologic basin • Surrounded by federal land • Protected by natural geologic barriers • Protected by robust engineered barriers and a flexible design