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Radiation Safety Training for User

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Title: Radiation Safety Training for User


1
Radiation Safety Training for Users
Elayna Mellas Radiation Safety Officer Environment
al Health Safety Manager Clarkson
University Downtown Snell 155 Tel
315-268-6640 emellas_at_clarkson.edu
This training course has been partially
adapted from slides provided by Steve Backurz,
Radiation Safety Officer of The University of New
Hampshire
2
Table of Contents
Subject Slides
Nuclear Physics 3-30
Biological Effects 31-43
Radiation Exposure and Dose 44-60
Uses of Radioactive Material 61-66
Radiation Hazards 67-80
Radiation Detection 81-87
Lab Procedures at Clarkson 88-115
3
Introduction
  • Radiation and radioactive materials are valuable
    tools used in research at Clarkson
  • Radio-labeling of biological materials
  • Sealed sources in chemistry/engineering
  • X-ray diffraction analysis of samples for
    chemistry and engineering research
  • Radioactive materials and X-ray machines are very
    safe if used properly and simple precautions are
    followed

4
  • Review of Atomic Structure
  • Nucleus
  • Contains protons and neutrons
  • Small Size
  • Relatively large mass
  • Extremely large density
  • Large amount of stored energy
  • Orbiting Electrons
  • Large size
  • Low density
  • Orbit nucleus near speed of light
  • Small amount of energy relative to nucleus
  • Responsible for chemical bonds

5
  • Nomenclature for Elements

"X" Element Symbol "Z" Protons Each
element has a unique "Z "N
Neutrons Atomic Mass "A" "A" Z N
Protons Neutrons Isotope same Z, different
N, thus different A
A
X
Z
6
  • Phosphorous-32 Atom

7
  • Radioactivity ("Activity")
  • Definition A collection of unstable atoms that
    undergo spontaneous transformation that result in
    new elements.
  • An atom with an unstable nucleus will decay
    until it becomes a stable atom, emitting
    radiation as it decays
  • Sometimes a substance undergoes several
    radioactive decays before it reaches a stable
    state
  • The amount of radioactivity (called activity)
    is given by the number of nuclear decays that
    occur per unit time (decays per minute).

8
  • The Curie
  • A unit of activity defined by the number of
    radioactive decays from a gram of radium
  • 1Curie (Ci) 2.22 E12 disintegrations/minute
    (dpm)
  • Sub-multiples of the Curie
  • millicurie 1 mCi 2.22 E9 dpm
  • microcurie 1 uCi 2.22 E6 dpm
  • nanocurie 1 nCi 2,220 dpm
  • picocurie 1 pCi 2.2 dpm
  • Typical activities at Clarkson are in the ?Ci to
    mCi range

9
  • Other Units of Measure
  • Disintegrations per minute (dpm)
  • Disintegrations per second (dps)
  • The SI unit for activity is the becquerel (Bq)
  • 1 Bq 1 disintegration/second
  • 1 Curie (Ci) 3.7 E10 Bq or 37 GBq
  • 1 millicurie 37 MBq
  • 1 microcurie 37 kBq

10
  • Ion
  • Any atom or molecule with an imbalance in
    electrical charge is called an ion
  • In an electrically neutral atom or molecule, the
    number of electrons equals the number of protons
  • Ions are very chemically unstable, and will seek
    electrical neutrality by reacting with other
    atoms or molecules

11
  • 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

12
  • The Electromagnetic Spectrum

13
  • Alpha Particles
  • Alpha particles
  • High mass (4 amu) 2 protons 2 neutrons
  • High charge (2)
  • High linear energy transfer (cause great
    biological damage)
  • Travel a few centimeters in air
  • Stopped by a sheet of paper or protective layer
    of skin
  • Not an external hazard
  • Concern would be for ingestion or inhalation

14
  • Beta Particles
  • Low mass (0.0005 amu)
  • Low charge - can be positively or negatively
    charged (/- 1)
  • Travel 10 - 20 feet in air
  • Stopped by a book
  • Shield betas with low density materials such as
    lucite or plexiglass
  • Shielding high energy betas like P-32 with lead
    can generate more radiation than it shields due
    to Bremsstrahlung X-rays

15
  • Gamma Radiation
  • Wave type of radiation - non-particulate
  • Photons that originate from the nucleus of
    unstable atoms
  • No mass and no charge
  • Travel many feet in air
  • Lead or steel used as shielding

16
  • Review of Nuclear Decay

17
  • Examples of Nuclear Decay

32
32
Beta Minus Decay (neutron-excess nuclides)
-
?
S
P

16
15
0
22
22
?

Beta Plus Decay (neutron-deficient nuclides)
Na

Ne
0
11
10
206
4
?
210
Alpha Decay (Heavy nuclides above atomic number
82)
Pb

Po
2
84
82
18
  • Decay Scheme
  • A decay scheme is a graphical representation of
    radioactive decay
  • Depicts the parent/daughter relationship
  • Branching fractions and energy levels are shown

19
  • Decay Law Half-Life
  • Half life The time required to reduce the amount
    of a particular type of radioactive material by
    one-half
  • Example 120 Ci of P-32 (t 1/2 14 days)

20
  • X-Rays
  • Wave type of radiation - non-particulate
  • Photons originating from the electron cloud
  • Same properties as gamma rays relative to mass,
    charge, distance traveled, and shielding
  • Characteristic X-rays are generated when
    electrons fall from higher to lower energy
    electron shells
  • Discrete energy depending on the shell energy
    level of the atom
  • Bremsstrahlung X-rays are created when electrons
    or beta particles slow down in the vicinity of a
    nucleus
  • Produced in a broad spectrum of energies
  • Reason you shield betas with low density material

21
  • Bremsstrahlung Radiation

Energy is lost by the incoming charged particle
through a radiative mechanism
Beta Particle
Bremsstrahlung Photon
-


Nucleus
22
  • X-Ray Machine Components

23
  • X-Ray Machine Basics
  • kVp - how penetrating the X-rays are
  • Mammography - 20 - 30 kVp
  • Dental - 70 - 90 kVp
  • Chest - 110 - 120 kVp
  • mA - how much radiation is produced
  • Time - how long the machine is on
  • Combination of the above determines exposure

24
  • Types of Radiation

Mass (amu)
Charge
Travel Distance in Air
4.0000
Alpha
2
few centimeters
Beta Plus
0.0005
1
few meters
few meters
Beta Minus
0.0005
-1
Gamma
0.0000
0
many meters
0.0000
X-Rays
0
many meters
Neutron
1.0000
0
many meters
25
  • Radiation, Radioactive Material,
  • and Contamination
  • Radiation Energy in the form of particles and
    waves
  • Radioactive Material Material that is unstable
    and emits radiation
  • Contamination Radioactive material where it is
    not wanted
  • Campfire example burning logs (radioactive
    material), heat (radiation), burning embers that
    escape the controlled area (contamination)

26
  • Interaction of Radiation
  • with Matter
  • Radiation deposits small amounts of energy, or
    "heat" in matter
  • alters atoms
  • changes molecules
  • damage cells DNA
  • similar effects may occur from chemicals
  • Much of the resulting damage is from the
    production of ion pairs

27
Ionization
  • The process by which a neutral atom acquires a
    positive or negative charge

28
  • Ionization

Ionization by a Beta particle
-
ejected electron
Beta Particle
-
-
-
Colliding Coulombic Fields
The neutral absorber atom acquires a positive
charge
-
29
  • Gamma Interactions
  • Gamma interactions differ from charged particle
    Interactions
  • Interactions called "cataclysmic" - infrequent
    but when they occur lot of energy transferred
  • Three possibilities
  • May pass through - no interaction
  • May interact, lose energy change direction
    (Compton effect)
  • May transfer all its energy disappear
    (photoelectric effect)

30
  • Compton Effect

An incident photon interacts with an orbital
electron to produce a recoil electron and a
scattered photon of energy less than the incident
photon
Before interaction
After interaction
Scattered Photon
-
-
-
-
-
-
-
-
Electron is ejected from atom
Incoming photon Collides with electron
31
  • Biological Effects of Radiation

32
  • Acute Exposure
  • Large Doses Received in a Short Time Period
  • Accidents
  • Nuclear War
  • Cancer Therapy
  • Short Term Effects (Acute Radiation Syndrome 150
    to 350 rad Whole Body)
  • Anorexia Nausea Erythema
  • Fatigue Vomiting Hemorrhage
    Epilation Diarrhea Mortality

33
  • Effects of Acute Whole Body Exposure on Man

34
  • Chronic Exposure
  • Doses Received over Long Periods
  • Background Radiation Exposure
  • Occupational Radiation Exposure
  • 50 rem acute vs 50 rem chronic
  • acute no time for cell repair
  • chronic time for cell repair
  • Average US will receive 20 - 30 rem lifetime
  • Long Term Effects
  • Increased Risk of Cancer
  • 0.07 per rem lifetime exposure
  • Normal Risk 30 (cancer incidence)

35
Cellular Effects
  • Ionization within body tissues similar to water
  • Ionization causes many derivatives to be formed
  • Peroxides
  • Free Radicals
  • Oxides
  • These compounds are unstable and are damaging to
    the chemical balance of the cell. Various
    effects on cell enzymes and and structures occur.
  • Radiation is not the only insult responsible
  • Pollutants
  • Vitamin imbalance (poor diet)
  • Sickness and Disease

36
  • Cellular Effects (con't)
  • 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 at High Acute Doses

37
  • Variations in Sensitivity
  • Wide variation in the radiosensitivity of various
    species
  • Plants/microrganisms vs. mammals
  • Wide variation among cell types
  • Cells which divide are more sensitive
  • Non-differentiated cells are more sensitive
  • Highly differentiated cells (like nerve cells)
    are less sensitive

38
  • Effects on the Fetus
  • The fetus consists of rapidly dividing cells
  • Dividing cells are more sensitive to radiation
    effects than nondividing cells
  • Effects of low level radiation are difficult to
    measure
  • A lower dose limit is used for the fetus

39
  • Genetic Effects
  • It is possible to damage the hereditary material
    in a cell nucleus by external influences like
    Ionizing radiation, chemicals, etc.
  • Effects that occur as a result of exposure to a
    hazard while in-utero are called teratogenic
    effects
  • Teratogenic effects are thought to be more severe
    during weeks 8-17 of pregnancy - the period of
    formation of the bodys organs
  • A higher incidence of mental retardation was
    found among children irradiated in-utero during
    the bombings of Hiroshima and Nagasaki

40
  • Maternal Factors Pregnancy

Statistically, a radiation exposure of 1 rem
poses much lower risks for a woman than smoking
tobacco or drinking alcohol during pregnancy
41
  • Dose Response Curves

42
  • Rate of Absorption
  • Most important factor in determining when effects
    will occur
  • Recovery is less likely with higher dose rates
    than lower dose rates for an equivalent amount of
    dose more permanent damage
  • More recovery occurs between intermittent
    exposures less permanent damage

43
  • Area Exposed
  • The larger the portion - the more damage (if all
    other factors are the same)
  • Blood forming organs are more sensitive
  • A whole body dose causes more damage than a
    localized dose (such as in medical therapy).
  • Dose limits take this into consideration

44
  • Radiation Exposure Dose

45
  • Background Exposure
  • Your exposure to radiation can never be zero
    because background radiation is always present
  • Natural Sources - Radon
  • Cosmic
  • Terrestrial
  • Technologically Enhanced Sources (Man-Made)
  • Healing Arts Diagnostic X-rays,
    Radiopharmaceuticals
  • Nuclear Weapons Tests fallout
  • Industrial Activities
  • Research
  • Consumer Products
  • Miscellaneous Air Travel, Transportation of
    Radioactive Material

46
  • Annual Dose from
  • Background Radiation

47
  • Cosmic Radiation
  • 2 x 10 particles (mostly protons) per second are
    incident on the atmosphere
  • Energy greater than one BILLION ELECTRON VOLTS
  • Interact with atoms in the atmosphere and produce
    secondary particles
  • muons, electrons, photons, and neutrons
  • responsible for cosmic dose

18
48
  • Terrestrial
  • Major sources
  • Potassium - a few grams per 100 grams of ground
    material
  • Thorium and Uranium - a few grams per 1,000,000
    grams of ground material
  • Dose due mainly to photons originating near the
    surface of the ground

49
  • Radon
  • Naturally occurring radioactive gas
  • Second leading cause of lung cancer
  • Estimated 14,000 deaths per year
  • Easy to test for
  • short and long term tests available
  • EPA guideline is 4 pCi/L
  • Fixable
  • Radon in water from drilled wells can also be an
    entry method

50
  • Exposure, X
  • A measure of the ionization produced by
  • X or Gamma Radiation in air
  • Unit of exposure is the Roentgen

51
  • Absorbed Dose, D
  • Absorbed Dose (or Radiation Dose) is equivalent
    to the energy absorbed from any type of radiation
    per unit mass of the absorber
  • Unit of Absorbed Dose is the rad
  • 1 rad 100 ergs/g 0.01 joules/Kg
  • In SI notation, 1 gray 100 rads

52
  • Dose Equivalent, H
  • One unit of dose equivalent is that amount of any
    type of radiation which, when absorbed in a
    biological system, results in the same biological
    effect as one unit of low LET radiation
  • The product of the absorbed dose, D, and the
    Quality Factor, Q

H D Q
53
  • Units of Dose Equivalent
  • Human dose measured in rem or millirem
  • 1000 mrem 1 rem
  • 1 rem poses equal risk for any ionizing radiation
  • internal or external
  • alpha, beta, gamma, x-ray, or neutron
  • In SI units 1 sievert (Sv) 100 rem
  • External radiation exposure measured by dosimetry
  • Internal radiation exposure measured using
    bioassay sample analysis

54
  • Quality Factors for Different Radiations

Quality Factor
X and Gamma Rays
1
Electrons and Muons
1
Neutrons lt 10 kev
5
gt10kev to 100 Kev
10
gt 100 kev to 2 Mev
20
gt2 Mev
10
Protons gt 30 Mev
10
Alpha Particles
20
55
  • External Dose
  • 2 Standard reference points
  • Shallow Dose Live skin tissue at an average
    depth of .007 cm.
  • Deep Dose Internal organs close to the body
    surface, 1 cm.
  • Shallow Dose Equivalent, SDE
  • Alpha radiation not a hazard
  • consider beta and gamma radiation.
  • Deep Dose Equivalent, DDE
  • Alpha and Beta radiation not a hazard.
  • For gamma, SDE DDE (typically)

56
  • Internal Dose
  • All radiation types present a hazard
  • 2 Dose quantities
  • Committed Dose Equivalent, CDE (specific to a
    particular organ)
  • Committed Effective Dose Equivalent, CEDE (sum of
    all organs x weighting factor for importance or
    each specific organ)

57
  • Total Effective Dose
  • Equivalent, (TEDE)
  • Used to combine internal and external doses
  • Puts all dose on the same risk base comparison,
    whether from external or internal sources.
  • TEDE CEDE DDE
  • All units are in rems or Sieverts (Sv)
  • All regulatory dose limits are based on
    controlling the TEDE

58
Standards for Rad Protection
  • Radiation Protection Program Required
  • Occupational Limits
  • 5 rem per year TEDE
  • 50 rem per year CDE (any single organ)
  • 15 rem per year lens of the eye
  • 50 rem per year skin dose
  • 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)

59
  • Declared Pregnant Woman
  • Voluntarily informs her employer in writing of
    pregnancy
  • Estimated date of conception
  • Dose limit is 10 of occupational limit (500
    mrem)
  • Avoid substantial variation in dose
  • Form for declaring pregnancy is on web site

60
  • Clarkson Anticipated
  • Worker Radiation Exposure
  • Anticipated Exposures Less than the minimum
    detectable dose for film badges (10 mrem/month) -
    essentially zero
  • Average annual background exposure for U.S.
    population 360 mrem/year
  • State and Federal Exposure Limits 5000 mrem/year

61
  • Uses of Radioactive Material

62
Consumer Products
  • Building materials
  • Tobacco (Po-210)
  • Smoke detectors (Am-241)
  • Welding rods (Th-222)
  • Television (low levels of X-rays)
  • watches other luminescent products (tritium or
    radium)
  • Gas lantern mantles
  • Fiesta ware (Ur-235)
  • Jewelry

63
Smoke Detectors
  • Alpha particles from americium-241 (red lines)
    ionize the air molecules (pink and blue spheres).
    The ions carry a small current between two
    electrodes. Smoke particles (brown spheres)
    attach to ions reducing current and initiate
    alarm.

64
Research at Clarkson Using Radiation Sources
  • Radioactive Materials (both open and sealed
    sources such as S-35, P-32, C-14, H-3, Xe-133,
    Ra-226, Am-241)
  • Gas Chromatographs (sealed sources)
  • Liquid Scintillation Counters (sealed sources for
    internal standards)
  • X-ray Diffraction equipment
  • Electron microscopes

65
  • Medical
  • Diagnostic
  • X-rays
  • Nuclear Medicine (Tc-99m, Tl-201, I-123)
  • Positron Emission Tomography (PET)
  • Therapeutic
  • X-rays (Linear Accelerators)
  • Radioisotopes
  • Brachytherapy (Cs-137, Ir-192, Ra-226)
  • Teletherapy (Co-60)
  • Radiopharmaceuticals (I-131, Sr-89, Sm-153)

66
Industrial Radiography
67
  • Radiological Hazards

68
Radiation Protection Basics
  • Time minimize the time that you are in contact
    with radioactive material to reduce exposure
  • Distance keep your distance. If you double the
    distance the exposure rate drops by factor of 4
  • Shielding
  • Lead, water, or concrete for gamma X-ray
  • Thick plastic (lucite) for betas
  • Protective clothing protects against
    contamination only - keeps radioactive material
    off skin and clothes

69
  • External Radiation
  • Inverse Square Law

70
  • Gamma Ray Constant
  • Gamma Ray Constant to determine exposure rate
  • ??(mSv/hr)/MBq at 1 meter
  • Hint multiply (mSv/hr)/MBq by 3.7
  • to get (mrem/hr)/uCi
  • Exposure Rate Calculation, X (mrem/hr) at one
    meter

X ??????? Where, A Activity (?Ci)
? ??Gamma Ray Constant(mSv/hr)/Mbq
3.7 is the conversion factor
71
Sample Calculation
  • 5 Curie Cs-137 Source
  • Calculate Exposure Rate at 1 meter
  • ? 1.032 E-4 mSv/hr/MBq _at_ 1 meter
  • X 1.032 E-4 3.7 5 Ci 1000 mCi/Ci 1000
    uCi/mCi
  • X 1909 mrem/hour
  • X 1.91 rem/hour

72
  • Gamma Ray Shielding
  • Effectiveness increases with thickness, d (cm)
  • Variation with material, (1/cm)
  • attenuation coefficients µ
  • High Z material more effective
  • Water - Iron - Lead
  • good - better - best

73
  • Shielding Beta Emitters
  • Low energy betas (H-3, C-14, S-35) need no
    shielding for typical quantities at Clarkson
  • Higher energy beta emitters (P-32) should be
    shielded
  • Beta shielding must be low Z material (Lucite,
    Plexiglas, etc.)
  • High Z materials, like lead, can actually
    generate radiation in the form of Bremsstrahlung
    X-rays
  • Bremsstrahlung from 1 Ci of P-32 solution in
    glass bottle is 1 mR/hr at 1 meter

74
  • Contamination and
  • Internal Hazards
  • Units of Measure
  • activity/area (dpm/100 square cm)
  • Fixed vs Removable
  • Internal Hazards and Entry Routes
  • Ingestion
  • Inhalation - Re-suspension
  • Skin absorption
  • Wound Entry

75
  • 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!

76
  • 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)
  • Have meter out and handy
  • 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

77
  • Avoid Ingesting
  • Radioactive Material
  • Dont bring hands or objects near your mouth
    during an experiment
  • Eating, drinking, smoking, applying cosmetics are
    strictly prohibited in radioisotope use areas
  • Never mouth pipette
  • Never store personal food items in refrigerators
    or freezers used for radioactive material or
    other hazardous material storage

78
  • Avoid Inhaling
  • Radioactive Material
  • Make sure you have proper ventilation for your
    experiments
  • When using volatile materials such as Iodine-125
    and some Sulfur-35 compounds, be sure to use a
    fume hood that has been inspected and certified
    for proper airflow

79
  • DAC's ALI's
  • DAC Derived Air Concentration, an airborne
    concentration of of radioactive material which if
    inhaled for 2000 hrs per year will result in 5
    rem CEDE or 50 rem CDE.
  • Units are uCi/cc
  • Each DAC-hour gives 2.5 mrem of dose.
  • ALI Annual Limit on Intake, A quantity of
    radioactive material, which if inhaled or
    ingested, would result in the applicable annual
    dose limit.
  • 1 ALI 5 rem (CEDE) or 50 rem (CDE)
  • ALI and DAC Values listed for each nuclide in
    NHRCR (He-P 4090)

80
  • External vs Internal Dose
  • TEDE Total Effective Dose Equivalent
  • TEDE DDE CEDE
  • Total Dose External Dose Internal Dose
  • 1 rem internal (CEDE) same as 1 rem external
    (DDE)
  • Internal dose is protracted over several years
    but calculated over 50 years and assigned in the
    year of intake

81
  • Radiation Detection

82
Radiation Detector Types
  • Solid State Detectors
  • Germanium Lithium High Purity
  • Silicone Lithium
  • Silicone Diode
  • Cadmium Telluride
  • Gas Filled Detectors
  • Geiger Mueller (GM)
  • Gas Flow Proportional Counters
  • Ionization
  • Scintillation Detectors
  • Sodium Iodide (NaI)
  • Zinc Sulfide (ZnS)
  • Anthracene
  • Plastic Scintillators

83
  • Gas Filled Detectors
  • Ionization detectors
  • High Cost
  • Survey meters
  • Reference class calibration chambers
  • Proportional counters
  • High cost
  • Gross laboratory measurements
  • Contamination monitors
  • Geiger Mueller (GM) detectors
  • Low cost
  • Survey meters
  • Contamination monitors

84
  • Scintillation Detectors
  • One of the Oldest Detection Methods, Still Widely
    Used Today
  • Transducer Converts Radiation Energy to Visible
    Light
  • Visible Light Signals Amplified With
    Photomultiplier Tube
  • Output PM Tube Signal Processed
  • High Efficiency For Photon Detection Compared To
    Gas-Filled Detectors

85
  • Applications of
  • Scintillation Counting
  • Laboratory
  • Liquid Scintillation Counters
  • gross counting
  • spectroscopy
  • Quenching
  • Field
  • Low Level Radiation Survey Instruments
  • Thyroid monitoring for Iodine uptakes

86
  • Use of Survey Instruments
  • Check Physical Condition
  • Cables, Connections, Damage
  • Check for Current Calibration (License
    Requirement)
  • Battery Check
  • Zero Check
  • Response check prior to use
  • Select Proper Scale
  • Response Time (Fast or Slow?)
  • Audio (On or Off)

87
  • CPM DPM
  • 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 that a detector sees
  • The efficiency of a detector is determined by the
    following
  • Efficiency net cpm / dpm
  • gross cpm background cpm / dpm

88
Regulatory Agencies
  • U. S. Nuclear Regulatory Commission
  • Regulates the nuclear industry pursuant to the
    Atomic Energy Act
  • Regulatory guides published to describe methods
    for complying with regulations
  • Agreement States
  • Some states have entered into an agreement with
    the NRC to regulate by-product material (and
    small quantities of source and special nuclear
    material)
  • Currently, 30 states are agreement states
    including New York

89
Radioactive Material at Clarkson
  • Activities are licensed by the State of New York
  • Radiation Safety Committee has responsibility to
    review, approve, and oversee activities
  • Radiation Safety Officer (RSO) runs program
  • Clarkson is required to
  • Train individuals that use sources of radiation
  • Train non-radiation workers that work in the
    vicinity of radiation sources
  • Monitor and control radiation exposures
  • Maintain signs, labels, postings
  • Manage and properly dispose of radioactive waste

90
Ordering Receiptof Radioactive Materials
  • Only RSO is authorized to order radioactive
    material
  • Use the Radionuclide Purchase Request Form
  • Complete form and fax to RSO at 268-7118
  • Be sure to state any special ordering
    instructions (preferred delivery date, fresh
    batch, etc.)
  • Packages are received by RSO, checked for
    contamination, logged in, and delivered to the
    lab on the same day as receipt

91
  • Specific Radioactive Materials
  • Tritium (Hydrogen-3)
  • 12.3 year half life
  • Very low energy beta (0.0186 MeV max)
  • No shielding needed
  • Surveys by wipe method counted on LSC
  • Carbon-14
  • 5730 year half life
  • Low energy beta (0.156 MeV max)
  • Shielding not needed
  • Spot checks with GM are possible but
    contamination surveys using wipes are necessary

92
  • Specific Radioactive Materials
  • Phosporous-32
  • 14.3 day half life
  • High energy beta (1.710 MeV max)
  • Shield with low Z material such as plastics
  • Do not use lead shielding
  • Wear safety glasses to shield eyes
  • Ring badges are required for handling millicurie
    quantities
  • GM survey meter required
  • Avoid handling containers for extended periods

93
  • Specific Radioactive Materials
  • Sulfur-35
  • 87.4 day half life
  • Low energy beta (0.167 MeV max)
  • Same general precautions as for C-14
  • Should be handled in a fume hood
  • Nickel-63
  • 100.1 year half life
  • Low energy beta (0.066 MeV max)
  • Gas chromatographs with electron capture detector
    cells
  • No shielding needed

94
Posting Labeling Notices
  • Posting
  • New York Notice to Employees form
  • Caution Radioactive Materials or X-Rays
  • Labels
  • All containers (unless exempt) must be labeled
  • With Caution Radioactive Material
  • Should include radionuclide, quantity, date,
  • initials, radiation levels, etc.

95
  • Employee Rights
  • and Responsibilities
  • Right to report any radiation protection problem
    to state without repercussions
  • Responsibility to comply with the Radiation
    Protection Program and the RSO's instructions
    pertaining to radiation protection
  • Right to request inspection
  • in writing
  • grounds for notice
  • signed
  • Responsibility to cooperate with NY State
    inspectors during inspections and RSO during
    internal lab audits

96
  • Access Restriction
  • Required by License and NY Regulations
  • Security and Control of Radioactive Material

97
  • Security
  • Licensed RAM must be secured against unauthorized
    removal at all times
  • Must maintain constant surveillance for any
    radioactive material outside a restricted area
  • Lock labs containing radioactive material if last
    one out - even if its just for a minute
  • Challenge all unknown individuals with May I
    help you?
  • OK to ask for ID
  • Report to supervisor if suspicious

98
  • ALARA
  • The goal of radiation protection is to keep
    radiation doses As Low As Reasonably Achievable
  • Clarkson is committed to keeping radiation
    exposures to all personnel ALARA
  • What is reasonable?
  • Includes -State and cost of technology
  • -Cost vs. benefit
  • -Societal socioeconomic
    considerations

99
Safe Use of Sealed Sources
  • Source sign out/in logs
  • Physical inventories
  • Leak Tests
  • Alpha sources every 3 months
  • Others every 6 months
  • Lost, stolen, or damaged sources must be reported
    to RSO
  • May require notification of the State

100
Surveys and Monitoring
  • Clarkson Radiation Protection Program specifies
  • Monitor all work areas at least once a week
  • Instrument surveys and/or wipe surveys should be
    done after each experiment or more often if
    needed
  • Isotope storage area must be surveyed at least
    once per month if no work is in progress
  • Must keep records of all required surveys for
    inspection by RSO and state inspectors
  • Survey equipment calibration intervals (12 months)

101
General Survey Information
  • Randomly survey selected areas outside of normal
    radioisotope use areas at least once a month to
    ensure there is no spread of contamination
  • Using a form with map of your lab on it is
    strongly recommended to make documenting surveys
    easier
  • Check wherever human hands and feet can go.
  • A good rule of thumb for determining if
    contamination is present is to look for 2X
    background
  • Common contamination sites include soap/towel
    dispensers, phones, chairs, desk tops, drawer and
    door handles, refrigerator handles, pens and log
    books, and the survey meter itself

102
Contamination Surveys
  • Direct monitoring with a Gieger Mueller detector
    can be performed when using P-32 and other high
    energy beta or gamma emitters
  • Wipe surveys for removable contamination must be
    used for low energy beta emitters (H-3, C-14,
    S-35)
  • Wipes are counted in a liquid scintillation
    counter
  • Direct monitoring for low energy gamma emitters
    should be done with a low energy gamma
    scintillation probe (NaI crystal)

103
Wipe Test Surveys
  • Wear gloves
  • Although a moistened swab or filter paper is more
    efficient, a dry filter or soft absorbent paper
    be used
  • Use uniform moderate pressure and wipe an area of
    at least 100 cm2 (about 4 X 4 or standard S
    swipe)
  • Keep each wipe separate to avoid cross
    contamination
  • Keep a record of the area wiped so that you know
    where the contamination is located if the wipe
    comes up hot
  • Place the wipe into a liquid scintillation vial,
    add cocktail, and count according to
    manufacturers procedure or your lab specific
    procedure
  • Results should be in dpm/100 cm2

104
Documenting Surveys
  • Contamination surveys must be documented
  • Record the following
  • Date performed
  • Areas surveyed (map is best)
  • Results in dpm/100 cm2 or mR/hour as applicable
  • Initials or name of surveyor
  • Instrument used and date of calibration
  • Action taken if contamination is found
  • Be sure to document all post-spill clean up
    surveys very well!

105
Decay-In-Storage of Wastes
  • Only for isotopes with half-lives less than 100 d
  • Keep all isotopes separate
  • Must keep an inventory with amount of activity
  • Remove or obliterate all radioactive labels prior
    to disposal
  • Store in labeled receptacle with clear plastic
    liner
  • Hold for 10 half-lives
  • Survey with appropriate detector and confirm
    indistinguishable from background
  • Dispose of without regard to radioactivity

106
Liquid Scintillation Waste
  • Use environmentally friendly cocktail (water
    soluble)
  • If tolulene/xylene based media must be used, keep
    separate
  • Must keep an inventory with amount of activity
  • Keep LSC separate from other liquid wastes
  • Store vials in flats, and check with RSO
    regarding method of disposal
  • Do not mix these with cocktails containing other
    radioactive materials

107
Liquid Waste Disposal
  • Readily soluble or readily dispersable biological
    materials in water may go down the drain if
  • No other hazard is present
  • The concentration does not exceed the allowable
    monthly average concentration
  • The total amount of radioactivity does not exceed
    50 ?Ci/day
  • The sink has been approved by the RSO and is
    appropriately designated and labeled
  • Must keep an inventory with amount of activity

108
General Spill Procedure
  • When cleaning up a spill, place absorbent
    material around the edges of the spill and clean
    from the outside edges toward the center to avoid
    spreading
  • Place materials used to clean the spill into
    appropriate radioactive waste containers
  • Notify others in the lab of the spill to prevent
    inadvertent spread of contamination
  • After clean-up, monitor all work areas using
    survey meter or wipe surveys, as applicable
  • Survey your hands, feet, clothing and all other
    materials that may have come in contact with the
    spilled material

109
Minor Spills
  • A minor spill is one that involves small
    quantities, low activities, low energy, or low
    hazard radioactive materials that are confined to
    a relatively small area
  • Most spills that could occur in the lab would be
    minor and should be cleaned up by lab personnel
    ASAP
  • Use the general spill clean-up procedure and
    common sense
  • You do not need to notify the RSO in the event of
    a minor spill

110
Intermediate Spills
  • An intermediate spill is one that involves larger
    quantities of radioactive material spread over a
    larger area
  • Intermediate spills could also involve small
    amounts of more hazardous radioactive materials
    such as higher energy emitters or volatile
    compounds
  • A spill outside a restricted area may also be
    considered intermediate since controlling the
    area may be difficult
  • Use the general spill clean-up procedure and
    common sense

111
Intermediate Spills (contd)
  • Wear gloves, lab coats, dosimetry, and other
    protective clothing
  • Confine the contamination
  • Prevent the spread of contamination
  • Use a survey instrument to check yourself for
    contamination before leaving the area
  • Pay special attention to hands and feet
  • Restrict access to the spill area
  • Inform others in the immediate area and post
    notice if necessary
  • Contact the RSO (x6640) to report the situation

112
Emergency Response
  • Fire in radioactive areas
  • Notify Fire Department and RSO, clear the area of
    people. Remove any seriously wounded persons.
    Keep your distance
  • Theft of radioactive materials
  • Notify RSO (info is posted on lab door)
  • State notification required
  • Notify RSO if you suspect
  • Inhalation, ingestion or other intake of
    radioactive material
  • Accidental release of radioactive material into
    the environment

113
Inspections
  • Inspections
  • NY shall be afforded opportunity to inspect at
    all reasonable times
  • Records shall be made available
  • Inspector may consult with workers privately
  • Worker may bring matters to inspector privately
  • Workers can request inspection
  • Must be in writing
  • Name is not revealed

114
Internal Audits
  • Internal audits by Clarkson RSO are performed in
    all labs on campus
  • Looking for same things as state inspector
  • Security of radioactive materials - including
    waste
  • Surveys for loose contamination
  • Proper procedures in use
  • Postings, container labeling, use of protective
    clothing, dosimetry, survey meters, calibrations,
    records of surveys, sink disposal logs, solid
    waste container logs, etc.

115
  • Your Role
  • in Radiation Protection
  • Report anything that looks out of the ordinary or
    if you are uncertain about what to do, where to
    go, requirements, exposures
  • Call the people on the emergency list
  • Ask the Radiation Safety Officer (RSO)
  • Elayna Mellas
  • 268-6640
  • emellas_at_clarkson.edu

116
Acknowledgements
This training course has been adapted from
slides provided by Steve Backurz, Radiation
Safety Officer of The University of New
Hampshire
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