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Annual Refresher Training

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Title: Annual Refresher Training


1
Annual Refresher Training
  • Radiation Safety

2
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

3
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

4
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

5
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

6
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

7
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

8
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

9
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.

10
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

11
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

12
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.

13
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.

14
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.

15
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.  

16
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.

17
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.

18
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

19
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

20
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

21
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

22
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.

23
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

24
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

25
The End
  • Youre Done! See you next year.
  • And dont forget to take the mandatory quiz.
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