Radiation Safety

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Radiation Safety

• Principles and Program Overview

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Introduction

• Radiation and radioactive materials are valuable
  tools used in teaching and research at UCF
• Radio-labeling of biological materials
• Sealed sources in chemistry, engineering
  physics
• X-ray diffraction analysis of samples for
  chemistry and engineering research
• These are safe if used properly and simple
  precautions are followed

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Background Radiation Is Always Present

• Soil - Radon (primary source)
• Sunlight - Cosmic Rays
• Man-Made - Nuclear, Medical, Industrial
• We are constantly exposed to low levels of
  background radiation. Background levels can vary
  depending upon location.

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Annual Dose from Background Radiation
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What Is Radiation

• Definition Energy in the form of particles or
  waves
• Types of Radiation
• Ionizing removes electrons from atoms
• Particulate (alphas and betas)
• Waves (gamma and X-rays)
• Non-ionizing (electromagnetic) can't remove
  electrons from atoms
• infrared, visible, microwaves, radar, radio
  waves, lasers
• Radioactivity is the rate of electron emission

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Electromagnetic Spectrum

• Ionizing Radiation
• X-Rays
• Gamma Rays
• Beta Particles
• Alpha Particles
• Neutrons

• Non-Ionizing Radiation
• Microwaves
• Radio Waves
• Infrared
• Laser

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Types of Radiation

• Alpha Particles
• Heavy, only travel an inch or so in air.
• Beta Particles
• Can travel a few feet. Will not penetrate much
  beyond depth of skin.
• Gamma and X-Rays
• Travel at speed of light. Can only be stopped by
  lead or concrete.
• Neutrons
• Very fast. Penetrating capability varies greatly
  on their energy.

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Ionizing Radiation

• Radioactive Materials
• P-32
• S-35
• C-14
• H-3
• I-125
• Can be alpha, beta or gamma emitters
• Different half lives

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Ionizing Radiation

• X-Ray Generating Equipment
• X-Ray Machines
• Particle Accelerators
• Electron Microscopes
• Some Lasers
• X-Ray Diffractometers
• Ion Implanters

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Biological Effects

• Acute Effects
• Large Doses Receive in Short Time Period
• Short Term Effects
• Acute Radiation Syndrome (150 to 350 rad Whole
  Body Dose)
• Anorexia, nausea, erythema, fatigue, vomiting,
  diarrhea, death

• Chronic Effects
• Doses Received over Long Periods
• Long Term Effects
• Increased Risk of Cancer
• 0.07 per rem lifetime exposure
• Latency can vary by decades

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Biological Effects

• Genetic Effects
• Can occur if radiation damages the chromosomes of
  the hereditary material passed from parents to
  offspring
• Tetratogenic effects are more severe during organ
  development
• Weeks 8-17 of pregnancy

• Somatic Effects
• Effects which directly damage the body
• Cells often recover from damage
• Repeated Insults may cause damage to be permanent
• Cell Death
• Cell Dysfunction - tumors, cancer, cataracts,
  blood disorders
• Mitosis (Cell Division) Delayed or Stopped
• Chromosomal breaks
• Organ Dysfunction

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Susceptible Tissues
NOTE
Fetus is most susceptible
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Radiation Units

• Rad Radiation Absorbed Dose
• Gray (GY) Absorbed Dose
• (1GY 100 Rad)
• Rem Roentgen Equivalent Man
• Sievert (Sv) Equivalent Dose
• (1 Sv 100 Rem)
• Curie (Ci) Measures Radioactivity
• Becquerel (Bq) (1 Bq 3.7x1010)

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Instruments for Radiation Detection

• A radiation detector will not detect every
  disintegration from a source (i.e., they are not
  100 efficient.
• Counts per minute (cpm) is the number of
  disintegrations the detector sees.
• Disintegrations per minute (cpm) can be
  calculated if you know the efficiency of your
  instrument
• dpm gross cpm background cpm/efficiency

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Instruments for Radiation Measurement

• Geiger Mueller Counters
• Must be calibrated annually-Takes Direct Readings

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Instruments for Radiation Measurement

• Ionization Chambers
• Must be calibrated annually-Takes Direct Readings

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Instruments for Radiation Measurement

• Gas Proportional Counters
• Must be calibrated annually-Wipes Then Read

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Instruments for Radiation Measurement

• Liquid Scintillation Counters
• Must be calibrated annually-Wipes Then Read

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Use of Survey Instruments

• Check Physical Condition
• Cables, Connections, Damage
• Check for Current Calibration (License
  Requirement)
• Battery Check
• Select Proper Scale (lowest for surveying)
• Response Time (Fast or Slow?)
• Audio (On or Off)

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Dosimeters

• Film Badges
• Photographic film. Darkens with radiation
  exposure. Permanent record.

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Dosimeters

• Thermoluminescent dosimeter (TLD)

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Dosimeters

• Pocket Dosimeter
• Short term monitoring.
• Direct Reading

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Dosimeters

• Optically Stimulated Luminescence (OSL)

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Wearing Dosimeters

• Whenever working with radiation
• Must face outwards
• Rings should be on hand closest to source
• Keep at work

• Keep away from machines and sources
• Do not wear during medical tests
• Do not expose to heat
• Do not deliberately expose

only wear to record OCCUPATIONAL EXPOSURE
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Standards for Radiation Protection

• Radiation Protection Program Required
• Occupational Limits
• 5 rem per year whole body DDE
• 15 rem per year lens of the eye LDE
• 50 rem per year skin dose SDE
• Members of Public
• 100 mrem per year
• No more than 2 mrem in any one hour in
  unrestricted areas from external sources
• Declared Pregnant Females (Occupational)
• 500 mrem/term (evenly distributed)

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Controlling Dose

• Time
• The shorter the time of exposure the less dose
  received. Dose Dose rate x Time.
• Distance
• The greater the distance from the source the less
  the dose received.
• Shielding
• Use the correct shielding and the proper
  thickness to lower exposures .

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Protective Clothing

• Can be a very effective means of preventing skin,
  eyes, clothing from becoming contaminated
• Gloves (may want double layer)
• Lab Coat
• Eyewear to prevent splashes and provide shielding
  for high energy beta emitters
• Closed toe footwear
• It is much easier to remove contaminated clothing
  than to decontaminate your skin!

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Contamination Control

• Watch out where you put your hot hands during
  an experiment
• Monitor yourself and your work area frequently
  for radioactivity (gloves, hands, feet, etc.)
• Use most sensitive scale on meter (X0.1 or X1)
• Make sure to wash your hands frequently and after
  finishing an experiment
• Dont bring radioactive material to lunch or to
  your home!
• Monitor your work area before and after an
  experiment

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Regulations

• Federal Regulations
• Nuclear Regulatory Commission. Title 10Code of
  Federal Regulations. (10CFR)
• State Regulations
• Florida Department of Health. Agreement State
  FAC 64E-5.
• Local Regulations
• Radiation Safety Committee. Radiation Safety
  Manual

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Management Responsibilities

• Has overall responsibility for radiation safety.
  Includes training, emergency response planning,
  as well as policies, procedures and resources to
  ensure a safe work place

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Individual Responsibilities

• Observe the regulations and recommendations
• Report conditions that could lead to violations
• Keep exposures As Low As Reasonable Achievable
• Report expected over-exposures
• Follow Radiation Safety Manual

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Radiation Safety Program at UCF

• RSO must be notified of all orders. All
  shipments received and checked in at EHS
• All RAM areas must be locked when unoccupied
• Surveys done weekly and after each experiment.
  Must be documented
• Audits and inspections

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Radiation Waste

• Waste disposal through EHS
• Collect liquid, solid and scintillation vials
  separately
• Deface all radiation labels before putting into
  solid waste containers
• Scintillation cocktails must be nonhazardous/keep
  haz waste and rad waste separately

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Forms