Chemeketa Community College Chapter 9: Nuclear Radiation Larry Emme Chemeketa Community College

Chapter Outline Radioactivity Nuclear Equations Radiation Detection Half-Life Medical Applications Fission & Fusion

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Biological Effects of Radiation Dose in rem (at one time) 0-25 genetic 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

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

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

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.

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

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

PET Scans Normal Alzheimer's

Known in Britain by the trade name ‘Pedoscope’ 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.

Shoe-Fitting Fluoroscope (ca. 1930-1940) Basic Description The shoe fitting fluoroscope was a common fixture in shoe stores during the 1930s, 1940s and 1950s. A typical unit, like the Adrian machine shown here, consisted of a vertical wooden cabinet with an opening near the bottom into which the feet were placed. When you looked through one of the three viewing ports on the top of the cabinet (e.g., one for the child being fitted, one for the child's parent, and the third for the shoe salesman or saleswoman), you would see a fluorescent image of the bones of the feet and the outline of the shoes.

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

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

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

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.

Trojan Nuclear Power Plant – Rainier, Oregon 46

May 21, 2006

Trojan Nuclear Reactor– Rainier, Oregon 48

Yucca Mountain in Nevada – site for nuclear depository?

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.

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

Cons: Nevada's Agency for Nuclear Projects Yucca's location in an active seismic (earthquake) region the presence of numerous earthquake faults (at least 33 in and around the site) and volcanic cinder cones near the site the presence of pathways (numerous interconnecting faults and fractures) that could move groundwater (and any escaping radioactive materials) rapidly through the site to the aquifer beneath and from there to the accessible environment. evidence of hydrothermal activity within the proposed repository block

Putting end to Yucca Mountain project ‘within reach,’ state commission says Jan. 21, 2013 http://www.lasvegassun.com/news/2013/jan/21/putting-end-yucca-mountain-project-within-reach-st/

The End

End of Chapter Learning Checks Try these after you have reviewed the chapter

Learning Check How many protons, neutrons and nucleons are found in the nuclide: 83 protons, 127 neutrons and 210 nucleons 210 protons, 83 neutrons and 127 nucleons 127 protons, 83 neutrons and 210 nucleons

Learning Check Answers How many protons, neutrons and nucleons are found in the nuclide: 83 protons, 127 neutrons and 210 nucleons 210 protons, 83 neutrons and 127 nucleons 127 protons, 83 neutrons and 210 nucleons

Learning Check A 4.0 g sample of Ra-226 decays to 1.0 g. If the half-life of Ra-226 is 1620 years, how much time has elapsed? 540 years 810 years 3240 years 4860 years

Learning Check Answers A 4.0 g sample of Ra-226 decays to 1.0 g. If the half-life of Ra-226 is 1620 years, how much time has elapsed? 540 years 810 years 3240 years 4860 years

Learning Check As the temperature of a solid radioisotope increases, its half-life Increases Decreases Remains the same

Learning Check Answers As the temperature of a solid radioisotope increases, its half-life Increases Decreases Remains the same

Learning Check Bismuth-210 decays by alpha decay to produce Tl-206 Au-206 Au-208 Au-214

Learning Check Answers Bismuth-210 decays by alpha decay to produce Tl-206 Tl-214 Au-206 Au-208 Au-214

Learning Check Carbon-14 is a beta emitter. What new nuclide is formed from the decay? B-14 N-14 Be-10

Learning Check Answers Carbon-14 is a beta emitter. What new nuclide is formed from the decay? B-14 N-14 Be-10

Learning Check Polonium-210 is both an alpha emitter and a gamma emitter. What is nuclide that forms as a result of this decay? Lead-206 Lead-214 Radon-206 Radon-214

Learning Check Answers Polonium-210 is both an alpha emitter and a gamma emitter. What is nuclide that forms as a result of this decay? Lead-206 Lead-214 Radon-206 Radon-214

Learning Check Which form of nuclear emission requires the greatest amount of shielding to provide protection from radiation injury? Alpha Beta Gamma

Learning Check Answers Which form of nuclear emission requires the greatest amount of shielding to provide protection from radiation injury? Alpha Beta Gamma

Learning Check What nuclide is formed when U-238 undergoes one alpha decay and two beta decays? U-238 U-234 Th-230

Learning Check Answers What nuclide is formed when U-238 undergoes one alpha decay and two beta decays? U-238 U-234 Th-230

Learning Check In an artificial transmutation process, a nucleus of Be-9 absorbs a proton, emits a particle, and is converted into Li-6. What was the particle emitted? A proton A neutron An electron An alpha particle

Learning Check Answers In an artificial transmutation process, a nucleus of Be-9 absorbs a proton, emits a particle, and is converted into Li-6. What was the particle emitted? A proton A neutron An electron An alpha particle

Learning Check A nucleus of U-235 absorbs a neutron, undergoes fission, and produces two fission fragments and two neutrons. One fission fragment is Xe-144, what is the other? Sr-90 Xe-91 Rb-88 Br-92

Learning Check Answers A nucleus of U-235 absorbs a neutron, undergoes fission, and produces two fission fragments and two neutrons. One fission fragment is Xe-144, what is the other? Sr-90 Xe-91 Rb-88 Br-92

Learning Check Which is true about ionizing radiation? It dislocates bonding electrons and creates ions It can damage DNA molecules Both large acute doses and small chronic doses are harmful All the above are true

Learning Check Answers Which is true about ionizing radiation? It dislocates bonding electrons and creates ions It can damage DNA molecules Both large acute doses and small chronic doses are harmful All the above are true