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Radiation Overview Presented by Capt. Colbrunn (Tank) Xenia Twp Fire Dept PowerPoint Presentation
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Radiation Overview Presented by Capt. Colbrunn (Tank) Xenia Twp Fire Dept

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Radiation Overview Presented by Capt. Colbrunn (Tank) Xenia Twp Fire Dept

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  1. Radiation Overview Presented by Capt. Colbrunn (Tank) Xenia Twp Fire Dept Used with permission from Wright-Patterson AFB Radiation Safety office -Unclassified -

  2. Ionizing Radiation Ionizing radiation consists of electromagnetic or particulate radiations capable of interacting with the atom causing removal of one or more electrons such that the atom has a resulting net positive charge

  3. DEFINITIONS • Radioactivity - a property of some species of atoms to spontaneously emit radiation(s) usually by disintegration of the nuclei of the atoms • Radiation - the energy or particles emitted when a radionuclide transforms or disintegrates (radiation is not the same as radioactivity) • Radionuclide - a nuclide that emits radiation(s)

  4. Ionizing Vs Non-ionizing x-ray machine microwave radar AM/FM gamma ray Ionizing Non-ionizing (Matching Game)

  5. Activity • curie (Ci) • The activity of 1 gram of 226Ra • 3.7 x 1010 disintegrations per second (dps) • becquerel • one disintegration per second (dps) • one dps is NOT synonymous with the number of particles emitted by the isotope in one second

  6. Half -life • The interval at which a radionuclide decays to one-half the original activity • Each radionuclide has its own characteristic half-life • Half-lives range from microseconds to billions of years RadionuclideHalf-life 57Co 270 days 241Am 433 years 63Ni 100 years 226Ra 1600 years 109Cd 464 days

  7. Decay Methods • Alpha (a) • Beta minus (b-) • Beta positive (b+) (positron) and Electron Capture • Gamma (associated with other types of decay)

  8. Line of Stability

  9. + + + Exposure • Roentgen (R) • the measure of the number of ion-pairs produced by gamma radiation in a certain volume of air

  10. DOSE • RAD (Radiation Absorbed Dose) • an absorbed radiation dose of 100 ergs per gram • energy deposited by any ionizing radiation in a unit mass of any absorber • Gray (Gy) • 1 Gy = 100 rads

  11. DOSE • REM (RAD Equivalent Man) • the absorbed dose (RAD) multiplied by a quality factor to equalize biological consequences • Sievert (Sv) • 1 Sv = 100 rems

  12. RadiationQuality Factor x-ray 1 gamma 1 beta 1 alpha 20 neutron (unknown energy) 10

  13. Exposure Vs Contamination • Exposure - the delivery of radiation to an individual that results in the receipt of a radiation dose • Contamination - radioactive material distributed in an unwanted place or location

  14. No biological sensors of ionizing radiation • Must depend on instruments • Interaction with matter principles used • Detection is dependent on type of radiation

  15. Dose Vs Dose Rate • Dose - generic term that means absorbed dose, dose equivalent, effective dose equivalent or total effective dose equivalent (mrem) • Dose Rate - the rate at which a dose is being delivered per a time interval (mrem per hour)

  16. Why does alpha have a higher quality factor? Radiation TypeIn AirTypical Shielding Material Used Alpha inches paper or aluminum foil Beta feet aluminum or Lucite Gamma hundreds lead or concrete of feet

  17. Internal Dose • Dose Equivalent (HT) - the product of the absorbed dose in tissue, quality factor, and all other necessary modifying factors at the location of interest. • Effective Dose Equivalent (HE) - the sum of the products of the dose equivalent to the organ or tissue (HT) and the weighting factors (WT) applicable to each of the body organs or tissues that are irradiated (HE = SWT HT)

  18. ORGAN DOSE WEIGHTING FACTORS 1 0.30 results from 0.06 for each of the “remainder” organs (excluding the skin and the lens of the eye) that receive the highest dose.

  19. Internal Dose • Committed Dose Equivalent (HT,50) - the dose equivalent to organs or tissues of reference (T) that will be received from an intake of radioactive material by an individual during the 50-year period following the intake • Committed Effective Dose Equivalent (HE,50) - the sum of the products of the weighting factors applicable to each of the body organs or tissues that are irradiated and the committed dose equivalent to these organs or tissues (HE,50 = SWT HT,50)

  20. Total Effective Dose Equivalent (TEDE) - the sum of the deep-dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures) TEDE = Deep Dose + CEDE

  21. Direct • ionization and excitation • radiation + H2O à H2O+ + e- à H+ + OH- • radiation + H2O à Ho + OHo (free radical) • occurs anywhere in body • Indirect • Radicals react with biological molecule and damage it • Radicals combine • OHo + OHo à H2O2 (hydrogen peroxide)

  22. Irradiated Cell Irradiated Cell Cell Division Parent Cell Division Growth No Division Daughter Cells Normal Mutant cells (death, altered DNA)

  23. Linear/Threshold Confirmed Data

  24. Most to least radiosensitive Immature male sex cells White blood cells Bone marrow cells Epithelial cells of the intestine Cells such as the skin covering external surfaces Cells that line the closed cavities of the body (i.e., heart, blood vessels) Bone cells Nerve cells Brain cells Muscle cells

  25. Radiation Effects Two types of exposure • Acute - a single accidental exposure to a high dose during a short period of time • Chronic - a long-term, low level exposure

  26. Acute Exposures • Factors • Type of radiation • Absorbed dose • Dose distribution • Age • Stages • Initial (nausea, vomiting) • Latent • Manifest illness • Recovery

  27. Acute Exposure Dose Effect 1 rad to bone marrow 20-50 rad (whole body) >90-150 rad (whole body) 300 rad (skin) 450 rads (whole body) 600-900 rad, (local to eye) >1000 -4000 rads (whole body) 10,000 rads (whole body) 1000-6000 (localized) risk of leukemia blood changes mild radiation sickness erythema LD 50/30 cataracts death in 1 to 2 weeks death in hours to days cancer treatments

  28. Chronic Exposure (Delayed Effects) • Cancer • leukemia • bone • lung • skin • etc. • Genetic • Life shortening

  29. Somatic - effects which occur to an individual being exposed during their lifetime • Genetic - effects that are act on the offspring of the individual being exposed

  30. Dose-Response Characteristics • Stochastic • effects that occur by chance • occur among unexposed as well as among exposed • in radiation, main effects are cancer and genetic effects • Non-Stochastic • certain minimum dose must be exceeded for effect • magnitude of effect increases with size of dose • clear causal relationship between exposure and effect

  31. RISKS • The human population has always received radiation exposure from natural sources such as cosmic, dietary, and soil. • Additional sources of exposure are medical exposures, occupations exposures and some industrial and consumer products.

  32. Annual effective dose equivalent in the U.S. population SourceAverage Dose (mrem) • Natural sources • Radon 200 • Other 100 • Occupational 0.9 • Nuclear fuel cycle 0.05 • Consumer products • Tobacco • Other 5-13 • Misc. Environ Sources 0.006 • Medical • Diagnostic x-ray 39 • Nuclear medicine 14

  33. Natural Radioactivity in Food Ref: http://www.physics.isu.edu/radinf/natural.htm

  34. Sources of Radiation Exposure Terrestrial 8% Internal 11% Cosmic 8% Medical X-rays 11% Nuclear Medicine 4% Consumer Products 3% Radon 55% Other <1% Occupational Nuclear Fuel Cycle Fall out Misc Average Exposure 360 mrem/yr

  35. Source of Radiation (excludes indoor radon) • 1. Cosmic Radiation: • 40 mrem a sea level • (Add 1 mrem for each 100 feet elevation) • 2. House Construction: • Wood: 35 mrem • Concrete: 50 mrem • Brick: 75 mrem • 3. Water and Food • a. U.S. average 25__ • b. Heavy smoker (add 30 mrem) • c. Drink beer • (add 1 mrem for each 100 bottles) _____ • 4. Air • a. Natural - U.S. average 5 • b. Weapons testing 2 • 5. Transcontinental Flights: • Add 4 mrem for each 5000 miles in flight • 6. Radium Dial Wrist Watch: (add 2 mrem) • Television: U.S. average 2__ • 8. Radioactivity in Human Body • a. Dose to yourself (K-40) 20__ • b. Sleep with spouse (add 0.3 mrem) • c. Dose to yourself (C-14) 0.2 9. Medical and Dental Diagnosis a. U.S. average 55 mrem or b. For each chest, teeth, head neck and bone x-ray, add 20 mrem c. For each spinal column and kidney x-ray , add 200 mrem d. For each stomach, intestines and gall bladder x-ray, add 250 mrem 10. Live in the vicinity of large coal-fired power plant (add 0.1 mrem) 11. Live in the vicinity of large geothermal power plant (add 1 to 100 mrem) 12. Nuclear Power Plants: a. If you live (1) At boundary fence (fraction of year spent times 5 mrem) (2) One mile away (fraction of year spent times 0.5 mrem) (3) Five miles away (fraction of year spent times 0.05 mrem ______ b. General U.S. population: Add 0.01 mrem Total mrem/year

  36. RISKS • It is estimated that if 100,000 persons of all ages received a whole body dose of 10 rad of gamma radiation in a single brief exposure, about 800 extra cancer deaths would be expected to occurduring their remaining lifetimes (BEIR V) • It is estimated that if 100,000 persons of all ages received a continuous lifetime whole body dose of 100 mrad per year, about 550 extra deaths would be expected. (BEIR V)

  37. Objectives of Radiation Protection • To prevent the occurrence of clinically significant radiation-induced deterministic effects by adhering to dose limits that are below the apparent threshold levels; and • To limit the risk of stochastic effects, cancer and genetic effects, to a reasonable level in relation to societal needs, values, benefits gained and economic factors NCRP No. 116

  38. External Radiation Protection Measures • Time • Distance • Shielding

  39. TIME • dose rate x exposure time = total dose 20 mRem/hr x 30 min = 10 mRem • Reduce time reduces exposure 1000 mR/hr for 2 minutes = ________________

  40. DISTANCE • Radiation exposure decreases with increasing distance • Decrease by inverse square law • Double the distance decrease the exposure by 4

  41. Alpha Beta Gamma and X-rays Neutron Shielding Lead Paper Plastic Concrete

  42. Response Actions • Fire, Explosion, Instrument Damage, etc. • Secure the area • Keep Unauthorized persons away • Alert people within the vicinity • Notify Department of Energy (DOE) • Initiate appropriate actions • Make appropriate written report • Loss or Theft • Immediate notification of DOE and Nuclear Regulatory Commission • Immediate notification of Radioisotope Committee • Make written report • Immediately begin search

  43. Susan, I see you have grown a foot since the last time I saw you !