nuclear safety

• Radioactive Sources


  • Radioactive Waste
  • Radon
  • X-Rays
  • Consumer Products
  • Nuclear Power
  • Nuclear Medicine
  • Solar Radiation
  • Cosmic Rays
  • Terrestrial Radiation
  • Food & Drink
  • Each Other
• Natural / Terrestrial Radiation


  • Common radionuclides created during formation of earth: Radioactive Potassium (K-40), Radioactive Rubidium (Rb-87)
  • Greatest contributor is 226Ra (Radium) with significant levels also from 238U, 232Th, and 40K
  • Igneous rock contains the highest concentration followed by sedimentary, sandstone and limestone
  • Fly ash from coal burning plants contains more radiation than that of nuclear or oil-fired plants
• Sea level - 30 mrem/year from cosmic radiation
• 10,000 ft. altitude - 140 mrem/year from cosmic radiation
• Man-made Radiation Sources


  • More sources of radiation in the consumer product category than in any other
  • Television sets - low energy x-rays
  • Smoke detectors
  • Treatment of agricultural products; long lasting light bulbs; building materials; static eliminators in manufacturing; and luminous dials of watches, clocks and compasses
• Annual Dose from Background Radiation: Total US average dose equivalent = 360 mrem/year
• ALARA


  As Low As Reasonably Achievable
• How to Implement ALARA

  1. Time

  2. Distance

  3. Shielding
• Time


  Less time = Less radiation exposure
• Distance


  Effective & Easy<|>Inverse Square Law: Doubling distance from source, decreases dose by factor of four<|>Tripling it decreases dose nine-fold<|>More Distance = Less Radiation Exposure
• Shielding


  Materials "absorb" radiation<|>Proper shielding = Less Radiation Exposure<|>Plexiglass vs. Lead
• Radiation Exposure Limits


  • Occupationally Exposed Worker: Whole body 5 rem, Eye 15 rem, Shallow 50 rem, Minor 0.5 rem, Pregnant Worker 0.5 rem
  • General Public: 100 mrem/year or 2mrem/hour
• Whole Body


  Total Effective Dose Equivalent (TEDE) = Internal + External<|>Limit = 5 rem / yr
• Ensuring Compliance to Radiation Exposure Limits

  1. Use established activity limit for each isotope

  2. Compare with similar situations

  3. Estimate with meter

  4. Calculate: Time, Distance, Shielding, Type, Energy, Geometry

  5. Measure: TLD Chip, Luxel
• Radiation Safety Practices


  1. Radiation use will be labeled on door, work area & storage area

  2. Safety can check for potential contamination prior to work in a lab that uses radioactive materials

  3. Wear gloves, safety glasses and wash hands
• Appropriate Lab Attire


  • Lab coat
  • Eye protection
  • Closed toe shoes
  • Personnel monitoring
  • Gloves
• Types of Badges Available


  • Those "likely" to exceed 10% of their annual limit are required
  • Those who would like a badge
  • Minors & Declared Pregnant Workers
• Laboratory Wipe Tests


  1. Fill out form RS-8

  2. Draw map of laboratory

  3. Take wipes of surfaces (10 cm2) throughout lab

  4. Run wipes monthly for possible contamination

  5. Document all information on form and place in Radiation Safety Binder
• Biological Effect


  Radiation may deposit Energy in Body, Cause DNA Damage, Create Ionizations in Body leading to Free Radicals which may lead to biological damage
• Radiation Effects on Cells

  • Radio sensitivity Theory of Bergonie & Tribondeau: Cells are radiosensitive if they have a high division rate, have a long dividing future, and are of an unspecialized type
  • Response to radiation depends on: Total dose, Dose rate, Radiation quality, Stage of development at the time of exposure
• Whole Body Effects


  • Acute or Nonstochastic: Occur when the radiation dose is large enough to cause extensive biological damage to cells so that large numbers of cells die off, Evident hours to a few months after exposure (Early)
  • Late or Stochastic (Delayed): Exhibit themselves over years after acute exposure, Genetic, Somatic, Teratogenic
• Most and Least Radiosensitive Cells

  • Low Sensitivity: Mature red blood cells, Muscle cells, Ganglion cells, Mature connective tissues
  • High Sensitivity: Gastric mucosa, Mucous membranes, Esophageal epithelium, Urinary bladder epithelium
  • Very High Sensitivity: Primitive blood cells, Intestinal epithelium, Spermatogonia, Ovarian follicular cells, Lymphocytes
• Comparison of Administrative, Regulatory and Biological Effect Doses


  • 100% of People Die, CNS Syndrome
  • Permanent Infertility
  • Whole Body Regulatory Limit (5 rem/yr)
  • Eye Regulatory Limit (15 rem/yr)
  • 50% of People Die (450 – 500 rad)
  • Nausea & Vomiting (10% of People)
  • Whole Body UTHSCH Administrative Limit (0.125 rem/month)
  • Eye UTHSCH Administrative Limit (0.375 rem/month)
  • Extremities UTHSCH Administrative Limit (1.275 rem/month)
  • General Public Whole Body Regulatory Limit (0.100 rem/yr)
  • No Clinical Symptoms Seen Below 10 rem
  • Cataract Formation
  • Loss of Hair
  • Skin Reddening
  • Decreased White Blood Cell Count
  • Ulcers on the Skin
  • Molecular Death (> 100,000 rad)
  • Gastrointestinal Syndrome
• Medical Treatment


  1. External Decontamination: Mild cleaning solution applied to intact skin, Never use harsh abrasive or steel wool

  2. Internal Decontamination: Treatment which enhances excretion of radionuclides
• Only 2% at the Level that Clinical Effects From Radiation Can be Seen
• Radiation does not give you super human powers
• Radiation will not make you glow in the dark