Annual Refresher Training

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Annual Refresher Training

• Radiation Safety

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Training Requirements

• In order to work with radioactive material you
  must be properly trained on the safe use and the
  minimization of risk associated with each
  isotopes.
• To keep your radiation worker status, you must
  have radiation safety refresher training once a
  year

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Radiation is energy traveling through space, its
most familiar form is sunshine

• Cosmic Radiation high energy particles and
  photons from the sun and other celestial sources
• Terrestrial Radiation radioactive materials
  occurring naturally in the earths crust
• Internal Radiation from radioactive materials
  incorporated in the human body
• Inhaled Radiation primarily radon and its
  progeny

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Properties of Radiation

• Radioactivity is the natural property of certain
  nuclides to spontaneously emit energy, in form of
  ionizing radiation, in an attempt to become more
  stable.
• Ionizing radiation has the ability to remove
  electrons from atoms, creating ions. Ionization
  is the product of negatively charged free
  electrons and positively charged ionized atoms

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Ionizing Radiation

• Particles
• Alpha 2 protons 2 neutrons
• Beta electrons emitted from nucleus
• Neutrons classified by energy
• Photons
• Gamma no mass, no charge, speed of light

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Radiation Units

• Rad (radiation absorption dose) is a measure of
  energy imparted to the medium
• Roentgen (R) is a measure of energy imparted to
  air, and the rem or dose equivalent takes into
  account effects from different types of ionizing
  radiation.
• Rem stands for Roentgen Equivalent Man, a unit
  of biological dose deposited in the body. The
  number of rems of radiation is equal to the
  number of rads absorbed multiplied by the
  relative biological effectiveness. One rem 10
  seiverts
• Curie (Ci) is the unit to measure a
  radioactivity, often expressed in smaller units
  like thousandths (mCi) or one millionth (uCi)
• One curie(Ci) 3.7 x 1010 dps (disintegrations
  per second)
• One millicurie(mCi) 3.7 x 107 dps 1 x 10-3
  Ci
• One microcurie (µCi) 3.7 x 104 dps or 2.22 106
  dpm (1 x 10-6 Ci)
• Becquerel (Bq) is a unit to measure a
  radioactivity, 1 transformation in one second,
  hence there are 3.7 x 1010 Bq in one curie

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ALARA

• Primary goal of radiation safety is to avoid any
  unnecessary radiation exposure and to keep all
  exposure
• As Low As Reasonable Achievable
• Three mains ways to keep your doses ALARA is
• Time
• Distance
• Shielding
• Note Obtaining higher doses in order to get the
  experiment done quicker is NOT reasonable

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Time, Distance, Shielding

• Time Decrease exposure time decrease the
  radiation dose proportionately.
• Distance The radiation dose rate varies with
  the inverse square of the distance of the source.
  Thus doubling distance from source will decrease
  the dose by factor of four
• Shielding
• Alpha is not an external hazard
• Beta stopped by ¼ inch of plexiglass, not lead
• Gamma stopped by high density materials such as
  lead

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Preventing Internal Exposure

• INTERNAL RADIATION EXPOSURE CONTROLFollow the
  precautions below to minimize internal radiation
  exposure
• Prevent absorption by changing your gloves
  frequently. Avoid touching your eyes, nose or
  mouth while conducting experiments. Monitor your
  work area with survey meter, wash your hands, and
  check your hands and lab coat with a survey
  meter.
• Prevent inhalation by using fume hood when you
  are using any volatile sources of radioactivity.
• Prevent ingestion by never eating, or drinking in
  the laboratory. Never store food in refrigerators
  or freezers or other areas designated for
  chemical or radioactive material storage.

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Preventing Internal Exposure

• Use protective clothing. Always wear a
  laboratory coat, gloves, and closed-toe-shoes
  when working with unsealed radioactive materials
• Avoid spreading contamination. Do not touch
  telephones, light switches, faucet handles, or
  doorknobs with gloved hands.
• Look for contamination. Frequent monitoring of
  hands, surfaces, and equipment will alert you to
  contamination

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Exposure Limits

• These limits are to ensure the risks from
  occupational radiation exposure levels are
  indistinguishable from other risks encountered
  from an average day of living
• Trunk of the body 5 rem/ year
• Extremities 50 rem/year
• Lens of the Eye 15 rem/ year
• Organ dose 50 rem/ year

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Exposure Limits

• Declared Pregnant Worker
• The occupational dose level for a declared
  pregnant worker is limited to 500 mrem during the
  entire gestation period, or an average of 50 mrem
  per month.
• The pregnant worker can only be monitored if she
  declares her pregnancy in writing to the
  Radiation Safety Officer.

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Survey Meters

• Check battery condition needle should go to BAT
  TEST line on meter
• Turn large switch to the lowest scale turn on
  audio switch.
• Note meter background reading in a location
  away from radiation source.
• Place probe (window face down) about ½ inch from
  surface being surveyed.
• Try not to let probe touch surfaces being
  checked.
• Survey work area by slowly moving probe over
  surfaces, listen to audible clicks from survey
  meter speaker.

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Surveys

• Routine surveys of laboratory areas are the only
  means to ensure a safe and contamination free
  working environment
• Before and after each experiment, surveys of the
  radiation use area using Geiger counter or wipe
  tests
• Monthly wipe tests of use areas and Geiger survey
  of storage area must be recorded and kept in
  laboratory.

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Wipe Samples

• With a cotton wafer, wipe an area of
  approximately 100cm2 (about the size of a U.S.
  dollar bill). You should wipe about 1 of the
  accessible surface area in hot area.
• In clean areas, take wipes of frequently used
  items or areas calculators, phones, door knobs,
  high traffic floors, etc.
• Count the wafer with at least 3 ml of safe
  scintillation cocktail, along with a background
  sample consisting of a new/unused, damp, cotton
  wafer, in a liquid scintillation counter (set to
  open or wide window). The results should be
  reviewed and data taped on the appropriate lab
  schematic, sign and date the form.  

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Wipe Tests

• How do I determine if an area is contaminated?
• Note Take gloves off before entering room.
• If the open-window count exceeds 200 cpm above
  background, you should recount the wipe vial
  before making it public to the other users in the
  room.
• If result is still above 200 cpm, you must
  decontaminate the area and perform another wipe
  test.
•  A meter reading two times background in any part
  of your lab area that has no nearby radioactive
  material storage or radioactive waste storage
  needs to be decontaminated. If area cannot be
  cleaned after two attempts, contact Radiation
  Safety officer for assistance.

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Half-life

• Half-life (T½) is the amount of time required for
  radioactive material to decrease by one half.
• Each radioisotope has a unique Half-life time
  period.

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Common Radioactive Materials in Laboratories

• Phosphorus - 32 (P-32) Half life 14.29
  days
• Pure beta emitter Eavg 0.695 MeV max range in
  air 20 feet Emax 1.71 MeV max range in
  lucite .02 inch
• Hazard External skin Internal Detection
  Survey meter
• Phosphorus 33 (P-33) Half life 25.3 days
• Pure beta emitter max range in air 20 feet
• Hazard- Slight external max range in lucite
  .02 inch
• Detection Survey meter
• Iron - 59 (Fe-59) Half life 44.5 days
• Low energy gamma X-rays Typical shielding
  needed (0.5 mm of lead)
• Hazard Internal organs Detection Survey
  meter

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Common Radioactive Materials in Laboratories

• Iodine-125 (I-125) Half Life 60.14 days
• Low energy gamma X-rays Typical shielding
  needed (0.5 mm of lead)
• Hazard External Internal Detection Survey
  meter
• Calcium 45 (Ca-45) Half life 162.7 days
• Pure beta emitter max range in air 20 feet
• Hazard- Whole body and bone max range in lucite
  .02 inch
• Cadmium-109 (Cd-109) Half Life 462.6 days
• Gamma X-rays Typical shielding needed (0.5 mm
  of lead)
• Hazard External Internal Detection Survey
  meter

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Radiation Spill Scenario

• Youve just spilled radioactive material on your
  lab coat and arm.
• Remove contaminated clothing and place them in a
  plastic bag
• Rinse exposed area thoroughly with soap and
  water, do not scrub
• Obtain medical attention if necessary
• Report the incident to your supervisor, and to
  the Radiation Safety Officer

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Incidents/ Accident Response

• A Minor Incident is radioactive material has been
  spilled with no personnel contamination and your
  are confident in your ability to contain and
  clean the spill.
• Confine the spill and notify others in area
• Cover spill with absorbent paper
• Verify the isotope and estimate the activity
  involved
• Begin decontamination efforts, working from outer
  edge of the spill in to the center
• Notify your supervisor and the Radiation Safety
  Officer of the incident

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Incidents/ Accident Response

• A Major incident is one where the radioactive
  material has been spilled and there is some type
  of personal contamination, high activity, or
  large area contamination, or you just arent
  confident that you can contain the material
• Notify others in the are and confine the spill
  and contaminated personnel
• Start decontamination procedures and notify
  Radiation Safety Officer as soon as possible
• Clean up and decontamination will be supervised
  by RSO.

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Incidents/ Accident Response

• An Emergency is a situation where radioactive
  material has been spilled and the spill involves
  a fire, explosion, or personnel injury
• Evacuate the area and call 5-111 or 911
• In injury involved administer first aid
• Contact Radiation Safety Officer as soon as
  possible

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Security

• Radioactive material must be secured from
  unauthorized persons. This mean that your
  radioactive material must be stored and used in a
  way that prevents unauthorized persons from
  gaining access to it.
• Principal investigators must determine the means
  used to assure security

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The End

• Youre Done! See you next year.
• And dont forget to take the mandatory quiz.