Radioisotope Laboratory Safety UCSC

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Radioisotope Laboratory SafetyUCSC

• Conrad Sherman x9-3911
• RSO/Health Physicist
• Marcus Balanky x9-5167
• ARSO/ Health Physicist
• Vern Ares x9-5167
• Assistant Health Physicist
• Environmental Health Safety
• Radiation Safety
• [phone] Environmental Health Safety
• Radiation Safety
• [phone]

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Radiation Safety
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Training Requirements

• Academic training
• Principles and practices of radiation protection
• Radioactivity measurements, monitoring
  techniques, and using instruments
• Mathematics and calculations basic using and
  measuring radioactivity
• Biological effects of radiation.
• Appropriate on-the-job-training
• Observing authorized personnel using survey
  equipment, collecting samples, and analyzing
  samples
• Using survey equipment, collecting samples, and
  analyzing samples under the supervision and in
  the physical presence of an individual authorized
  to perform surveys.
• NUREG 1556 Volume 11 Appendix S

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You are here
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A Banana Slug
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Required reading
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What is the purpose of safety training?
To increase your knowledge to enable you to
perform your job safely by adhering to proper
radiation protection practices while working with
or around x-ray generating devices.
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Radiation Units

• Roentgen (R) The roentgen (R) is a unit of
  radiation exposure in air.
• It is defined as the amount of x-ray or g
  radiation that will generate 2.58E-4 coulombs/kg
  of air at standard temp and pressure.
• rad RAD stands for Radiation Absorbed Dose and
  is the amount of radiation that will deposit 0.01
  J/kg of material.
• A roentgen in air can be approximated by 0.87 rad
  in air, 0.93 rad in tissue, and 0.97 rad in bone.
  
• Dose
• The SI unit of absorbed dose is the gray (Gy),
  which has the units of J/kg. 1 Gy 100 rad.

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Radiation Units

• REM REM stands for Roentgen Equivalent Man. The
  REM is a unit of absorbed dose and is equal to
  the rad multiplied by a weighting factor which
  varies according to the type of radiation. The
  weighting factor for x-rays is equal to 1.
• For x-rays, one rem is equal to one rad.
• The SI unit used in place of the rem is the
  sievert (Sv). 1 Sv 100 rem.

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Radiation Sources

• X-ray diffraction is a source of very intense
  radiation.
• The primary beam can deliver as much as 400,000
  R/minute
• Collimated and filtered beams can produce about
  5,000 to 50,000 R/minute
• Diffracted beams can be as high as 80 R/hour

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Fundamental Radiation Physics

• Radioactivity spontaneous nuclear
  transformations
• Generally alpha particles and beta particles
• Often accompanied by gamma ray emission
• Radiation alpha particles, beta particles,
  gamma rays, etc.
• Ionizing Radiation radiation capable of
  producing charged particles (ions) in the
  material through which it passes

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Four principal kinds of ionizing radiation
Kind Atomic Mass Electrical Charge Range in Air Range in Body Tissue Attenuation Exposure Hazard
Alpha 4 2 lt inch Unable to penetrate skin Stopped by a sheet of paper or skin Internal
Beta 1/1840 -1 Several feet 1/3 inch Stopped by a thin sheet of aluminum Skin, eyes, and internal
Gamma / x-ray NA None Passes through Passes through Thick lead or steel External and internal
Neutron 1 Neutral Hundreds of feet About 10 goes through Several feet of water or plastic Primarily external
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Radiological Fundamentals
The basic unit of matter is the atom.
Nucleus
Electron
Nucleus
Neutrons
Protons
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X-RAY AND GAMMA ( ) RAY PROPERTIES

• Cloud Charge None
• Mass None
• Velocity 3 x 108 m/s
• Origin
• Rays Nucleus
• X Rays Electron Bremsstrahlung

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General Radiation

• Radiation is energy in transit in the form of
  high speed particles and electromagnetic waves.
  We encounter electromagnetic waves every day.
  They make up our visible light, radio and
  television waves, ultra violet (UV), and
  microwaves with a spectrum of energies. These
  examples of electromagnetic waves do not cause
  ionization of atoms because they do not carry
  enough energy to remove electrons from atoms.

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General Radiation

• Ionizing radiation is radiation with enough
  energy so that during an interaction with an
  atom, it can remove tightly bound electrons from
  their orbits, causing the atom to become charged
  or ionized. Ionizing radiation deposits energy
  at the molecular level, causing chemical changes
  which lead to biological changes. These include
  cell death, cell transformation, and damage which
  cells cannot repair. Effects are not due to
  heating.

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Visible Light

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X-rays on EM spectrum
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Background Radiation
Cosmic - 28 mrem
Radon - 200 mrem
Diet - 40 mrem
Terrestrial - 28 mrem
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Man-made Radiation
Cigarette smoking - 1300
Medical - 53
Fallout lt 1
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Dose Limits

• EPA Guidance for dose limits
• NRC Regulations for dose limits
• DOT Regulations for transport
• State Agreement States
• Licensee Institutional Admin Limits

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Regulatory Limits

• Radiation Worker
• Whole Body
• Extremities
• Skin and other organs
• Lens of the eye
• Non-Radiation Worker
• Embryo/fetus
• Visitors and Public

• 5 rem/year
• 50 rem/year
• 50 rem/year
• 15 rem/year
• 0.5 rem/year
• 0.5 rem/gestation period
• 0.1 rem/year

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ALARA Program

• As Low As Reasonably Achievable
• Responsibility of all employees
• Exposures shall be maintained ALARA
• Below regulatory limits
• No exposure without commensurate benefit

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Responsibilities for ALARA
Ultimately YOU are!
Management

• To establish a program
• Meet regulatory limits

Safety Organization

• Implementing a program
• Run the daily operation

Radiation Worker

• To follow program

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General Methods of Protection

• Time

• Distance

• Shielding

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What are x-rays?

• X-rays are photons (electromagnetic radiation)
  which originate in the energy shells of an atom,
  as opposed to gamma rays, which are produced in
  the nucleus of an atom.

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X-RAY AND GAMMA ( ) RAY PROPERTIES

• Charge None
• Mass None
• Velocity 3 x 108 m/s
• Origin
• Rays Nucleus
• X Rays Electron Cloud
  Bremsstrahlung

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Ionizing Radiation
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Legal Limits
ANNUAL OCCUPATIONAL DOSE LIMITS
EXTENAL mRem DEEP DOSE 5,000 EYE DOSE 15,000 SKIN
DOSE 50,000 EXTREMITY DOSE 50,000 ORGAN
DOSE 50,000
INTERNAL uCi H-3 80,000 C-14
2,000 P-32 900 P-33 8,000 S-35 10,000 I-
125 60 ALLOWED LIMIT OF
INTAKE (INHALATION-INGESTION)
Note DOSE INTAKE 5 REMS ALI
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Pregnancy Policy
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Ordering Procedures for Radioactive Material
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Receipt Record

• Sign for package on Receipt and Use Log form

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Receipt and Use Log

• Record
• Use (, volume, or activity)
• Name
• Date
• Purpose
• Use blank column for other units

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Waste Tracking Form
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Laboratory and Material Security

• Avoids deliberate misconduct
• Lock and key storage
• Lock lab
• Challenge response to unknown intruders

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Avoid Ingesting Radioactive Material

• NO
• Eating
• Drinking
• Smoking
• Applying Cosmetics
• Mouth Pipetting

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Protective Clothing

• Gloves
• Lab coat
• Eyewear
• Pants
• Closed toe footwear

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Instrumentation
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Liquid Scintillation Counter

• Excellent choice for detecting and measuring low
  energy beta
• Not portable - wipe or smears required for
  radiation survey use
• Requires more training to prepare samples and
  interpret results than other instruments

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General Tips LSC Wipe Survey

• Survey discrete areas so that if contamination is
  found the spot will be easy to identify
• Avoid cross contamination of samples
• Artifacts may cause false positives
• Static electricity
• Chemoluminescence
• Phosphorescence

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User Program 10

• EHS Radiation Safety provides a user program for
  wipe surveys.
• Please use this program for your routine
  laboratory wipe surveys.
• We can provide an efficiency for the isotope you
  are using.

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Calibration and Maintenance

• Annual calibration required
• Electronic calibration
• Calibration in a known radiation field
• Efficiency determination
• Routine operational checks
• Be sure to turn off the instrument when done.

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D
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View Video
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Contamination Defined

• What is background?
• Background a representative sample of an area
  that is not expected to have been contaminated,
  for example, the hallway wall, window pane in a
  lab, or office phone.
• Blank clean wipe filter paper that has not been
  swiped.  
• What is the 2X Background Rule?
• Contamination suspected if counts are 2-3x
  background

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Pipet use
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Radiation vs. Radioactive Contamination

• Radiation is particles or waves of energy emitted
  from unstable atoms.
• Radioactive Contamination is radioactive material
  usually in any location you do not want it.

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Monitoring for contamination
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Removing Your Gloves
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Documenting Surveys

• Contamination surveys must be documented
• Record the following
• date performed
• area(s) surveyed (a map helps!)
• results
• identity of surveyor
• instrument used
• action taken if contamination is found

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Decontamination Procedures

• Area and Material Decontamination
• Wear protective clothing
• Clean in an inward direction
• Personnel Decontamination
• Flush with water first
• Soap and water only!!!
• Report to Occupational Health before attempting
  any stringent measures

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Radioactive Waste Disposal Procedures

• Guidelines at UCSC
• Minimizing waste production
• Reducing mixed waste
• Decontamination
• Getting the lead out

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Radioactive Waste

• Research involving radioactive material generates
  contaminated waste. EHS Radiation Safety supplies
  containers and removes radioactive waste from
  campus labs.
• The laboratory staff is responsible for
  monitoring, labeling, maintaining and preparing
  their waste for disposal.

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Radioactive Waste Disposal Instructions
For Segregation

• PACKAGING DRY WASTE
• PACKAGING SCINTILLATION VIALS
• PACKAGING BULK AQUEOUS LIQUIDS
• PACKAGING ABSORBED LIQUIDS

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Disposal of Shipping Containers

• Containers should be disposed of as
  non-radioactive waste.
• Remove or deface any radioactive material labels
  before disposal.

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Storage of Radioactive Waste

• Each radioactive waste container must have a
  Caution Radioactive Materials sign/label
• Radioactive waste containers must be stored in a
  controlled area

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Dry Solid Radioactive Waste

• No sharps
• No Liquids
• No lead or metals
• No high activity (stock vials)

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Liquid Radioactive Waste

• Store in 2.5 gal plastic carboys with
  secondary-containment.
• pH must be adjusted to between 6 and 9.
• Identify chemical contents including
  non-hazardous and hazardous components.

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Radioactive Sharps

• Radioactive sharps are items such as razor
  blades, scalpels, syringes and hypodermic
  needles.
• Plastic and glass pipette tips, broken glassware,
  etc. should not be disposed of as radioactive
  sharps.
• Contact the Natural Science Stockroom for
  radioactive sharps containers.

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Emergency Procedures
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Small (Minor) Spill

• Most spills that occur in the lab are minor, and
  should be cleaned up by lab personnel ASAP.
• You do not need to inform EHS Radiation Safety
  in the event of a minor spill.

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Small Spill Procedures

• Confine the spill
• Decontaminate the area
• Notify your supervisor
• Make a record.

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Large Spills- What to Do

• Confine contamination do NOT track contamination
  outside the area.
• Restrict access to the spill area
• Notify EHS Radiation Safety (9-2553), then your
  supervisor.
• You will not be penalized for reporting a spill,
  but on the other hand...

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Other protocols
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iodination
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Were there for you.

• Environmental Health Safety x9-2553
• Conrad Sherman x9-3911
• RSO/Health Physicist
• Marcus Balanky x9-5167
• ARSO/ Health Physicist
• Vern Ares x9-5167
• Assistant Health Physicist
• Environmental Health Safety
• Radiation Safety
• [phone]

Web site http//www.ehs.ucsc.edu/
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Quiz

• Question Number 1- Biology
• In experiments with certain cells, it is found
  that survival is exponential as a function of
  dose. What dose is the lethal dose to half the
  cells?
• Question Number 2 Chemistry
• In experiments with P-32, it is found that the
  number of atoms remaining is exponential as a
  function of time. What time is required for half
  the atoms to disintegrate?
• Question Number 3 Physics
• In experiments with shielding it is found that
  the Cs-137 gamma ray photo attenuation is
  exponential as a function of density. What
  thickness of lead is required for half the
  photons to be attenuated?

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Quiz Question 1

• In experiments with certain cells, it is found
  that survival is exponential as a function of
  dose. The relative number of cells N/No that
  survive an absorbed dose D is given by N/No
  e(-kD), where k is a constant.
• If only 1 of the cells survive a dose of 3850
  rad, what is the numerical value of K?
• What dose is the lethal dose to half the cells?
• How is k related to the average dose for killing
  a cell?

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Quiz Question 1 Answer

• If only 1 of the cells survive a dose of 3850
  rad, what is the numerical value of K?
• N/No 0.01 e-3850k
• K 1.20 x 10-3 rad-1 0.00120/rad
• What dose D50 is the lethal dose to half the
  cells?
• N/No 0.50 e-0.00120D50
• D50 578 rad
• How is k related to the average dose for killing
  a cell?
• K is a quantity with the dimensions of reciprocal
  dose.
• The dose 1/k gives the survival level N/No e-1
  0.37 D37 or the dose that gives 37 survival.

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Quiz Question 2

• In experiments with P-32, it is found that the
  number of atoms remaining is exponential as a
  function of time.
• The relative (radio)activity A/Ao is given by
• A/Ao e(-?t),
• where ? is a constant called the decay constant.
• ? ln (2) t / t1/2
• What time (t) is required for half the atoms to
  disintegrate?
• What is the mean lifetime of a P-32 atom?
• Hint Enter the terms you see in this problem in
  a Google search, and eventually you will be able
  to work out the answer.

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Quiz Question 3

• In experiments with shielding it is found that
  the gamma ray photo attenuation is exponential as
  a function of density. What thickness of lead is
  required for half the photons to be attenuated?
• I/Io e(-µx),
• where µ is the attenuation coefficient
• and x is the thickness of lead.
• Hint Enter the terms you see in this problem in
  a Google search, and eventually you will be able
  to work out the answer.