radiation safety capt. david ayre cap, swr-tx-176
TRANSCRIPT
Radiation SafetyCapt. David Ayre CAP, SWR-TX-176
RADIATION
The definition of radiation is the emission (sending out) of waves and/or particles thru space.
TYPES OF RADIATION
TYPES OF RADIATION
• heat
• light
• radio waves
• x-rays
• nuclear
IONIZING OR
NON - IONIZING
• non -ionizing• non - ionizing• non - ionizing• ionizing• ionizing
Nuclear Radiation
One source of radiation is the nuclei of an unstable atom. These radioactive atoms become more stable when the nuclei ejects or emits subatomic particles and/or high-energy photons (gamma rays).
This Is the Way the Atom Probably Looks
NucleusProton
Neutron
Electron
Atomic StructureAtomic Structure
Atomic NumberAtomic number (Z number)
is the number of PROTONS in the nucleus of an atom.
Atomic MassAtomic Mass
(A number),
is the number of PROTONS plus
the number of NEUTRONS in
the nucleus of an atom.
Mass and Charges of Basic Atomic Particles
MassMass ChargeCharge
Proton 1 amu + 1
Neutron 1 amu0 or
neutral
Electron1/2000 amu
- 1
ISOTOPEAtoms with the same atomic number,
but different atomic mass.
6 Protons
6 Neutrons
6 Protons
7 Neutrons
6 Protons
8 Neutrons
Carbon-12(6P + 6N)
Atomic Mass = 12
Carbon-13(6P + 7N)
Atomic Mass = 13
Carbon-14(6P + 8N)
Atomic Mass = 14
IODINE ISOTOPE EXAMPLE
Isotope Atomic MassAtomic Number
Number of Neutrons
I 123 123 53 70
I 125 125 53 72
I 131 131 53 78
Discovery of RadiationHenri Becquerel 1896
Marie Curie-To describe the behavior of uranium and thorium she invented the word “radioactivity” --based on the Latin word for ray.
Ernest Rutherford
Wilhelm Roentgen 1895
RUTHERFORD’S EXPERIMENT
Photographic Plate
TYPES OF RADIATION
Types of Radiation
Mass Charge Stopped By
Alpha 4 + 2 Thin Sheet of Paper
Gamma Ray
No Mass No Charge Several Inches of Lead or Steel
X Ray No Mass No Charge Several Inches of Lead or Steel
Beta 1/2000 - 1 Thin Aluminum
Neutron 1 0 High Hydrogen Content
Electromagnetic Spectrum
INDUSTRIAL USES OF RADIOACTIVE MATERIALS
Power Plants
Medical
Farming
Ranching
Textile
Auto
Soda Can
CASES OF HIGH OCCUPATIONAL EXPOSURE TO RADIATION
Early Scientists
Watch Dial Painters
Nuclear Weapons Research
Military Personnel
Emergency/Medical Personnel
Giga (G) = 1 billion
Mega (M) = 1 million
kilo (k) = 1 thousand
milli (m) = 1 thousandth
micro (u) = 1 millionth
COMMON PREFIXES
The SI UNIT is the_____Becquerel____
which is one nuclear transformation or one disintegration
per second.
Curie
A UNIT used to measure
the activity of a
radioactive source and
equals
37,000,000,000
disintegration's per
second.
UNITS OF MEASUREMENTUNITS OF MEASUREMENT
RoentgenA measure of theionization effect
Gammaand
X radiation have in AIR.
UNITS OF MEASUREMENT
REMA measure of the
biological effect
radiation has on man.
REM
stands for
Roentgen Equivalent Man
UNITS OF MEASUREMENT
Half-LifeThe time required for the amount of
radioactive material to decrease by one
half.
Original Material
Material after one Half-Life
Material after two Half-Lives
HALF-LIVES OF VARIOUS ISOTOPES
IsotopeHalf-Life
Am 241 454 Years
Cs 137 30 Years
Ra 226 1602 Years
I 131 8 Days
Co 60 5.2 Years
FILM BADGES
Radiation will expose film just as
light will.
The greater the dose of radiation the darker the film
will become.
Detecting Radiation and thePHOTOGRAPHIC PROCESS
0561420 T
N JAN 01, 1997 Z1
030000 T29 07469
John DoeLANDAUERLANDAUER
TLD’s use three chips that when
exposed to radiation store the energy.
When the chip is heated it gives off
light proportional to the radiation
absorbed.
THERMOLUMINESCENT THERMOLUMINESCENT DOSIMETERDOSIMETER
OSL’s use two thin Al2O3 strips which when exposed to radiation record Photons (X & d Rays) in the 5 keV / 40 MeV range & Beta Particles in the 150 keV / 10 MeV range.
During analysis, the Al2O3 is stimulated with selected frequencies of laser light, which cause it to become luminescent in proportion to the amount of radiation exposure received.
A third component, for the measurement of Neutrons, is also enclosed. This is a Neutrak 144 Allyl Diglycol carbonate solid state track detector. In this case measurement is made by chemical etching followed by track counting. Energies measured are between 100 keV / 30 MeV.
JOHNDOE
TRAINING
luxelLANDAUER
®
FRONT
OPTICALLY STIMULATED LUMINESCENCE (OSL) OPTICALLY STIMULATED LUMINESCENCE (OSL) DOSIMETERDOSIMETER
Dose Measurement Range
Photon 1 mREM to 1000 REM
Beta Particle 10 mREM to 1000 REMNeutron 20 mREM to 25 REM
Accuracy
Deep DoseDeep Dose = ±15% at the 95% confidence interval for photons above 20 keV
Shallow DoseShallow Dose = ±15% at the 95% confidence interval for photons above 20 keV and beta particles above 200 keV
01 - 01 - 99
0030000 T29 04839
Whole Body (chest)
0554677A2
3073
719
BACK
OPTICALLY STIMULATED OPTICALLY STIMULATED LUMINESCENCE (OSL) LUMINESCENCE (OSL)
DOSIMETERDOSIMETER
OPTICALLY STIMULATED OPTICALLY STIMULATED LUMINESCENCE (OSL) DOSIMETERLUMINESCENCE (OSL) DOSIMETER
The OSL is the principle deviceused to measure radiation exposure personnel.
The OSL will only measure what your body will receive and does not
“protect” from radiation.
A OSL will simply measure what you have been exposed to and willallow us to determine if you havereceived to much radiation.
JohnDoe
TRAINING
luxelLANDAUER
®
RADIATION MONITORING
Radiation Quality is an indication
of the type of radiation received
Radiation Quality Type of Radiation Received
P Gamma Only
CPN Combination Gamma and Neutron
NF Fast Neutron
M Minimal (Less than 1.0 mR)
MAXIMUM PERMISSIBLE MAXIMUM PERMISSIBLE EXPOSURESEXPOSURES
5 REM per Year
Lifetime Dose – ( Age - 18 ) * 5 REM
Recommended exposure while pregnant
500 mREM
Average exposure for Wireline
Logging & Perforating Personnel
150 - 250 mREM per Quarter
Detecting Radiation and the ENCLOSED GAS VOLUME PROCESS
Geiger-Mueller Counters
An enclosed tube has an anode and a cathode and usually an inert gas inside the tube. The radiation enters the tube ionizing the gas thus creating a current flow. The amount of radiation is proportional to
the current flow.
Electrical Current
Measuring Device
Anode +
Cathode -
+ -Voltage Source
Inert Gas
Incident Ionizing Radiation
Detecting Radiation and the SCINTILLATION CRYSTAL PROCESS
e-
e- e- e-
e-e-
P
Optical CouplingGrease
Scintillating Crystal
Preamp
HighVoltage
Dynodes
Photo-Cathode
GlassVacuum Tube
e- ElectronsP Photons
Gamma Ray
Photo-MultiplierTube
A
Milliroentgens
50 100 150 2000
EYEPIECE
D
LENS
C
B
+ +
+ +- -
- -
DIRECT - READING POCKET DOSIMETER
A. Charging Rod
B. Metal Support for Fibers
C. Movable Fine Metal Coated Quartz Fiber
D. Transparent Scale
LENS
Detecting Radiation and the Direct-Read Pocket Dosimeter
493VICTOREEN
mR/h
0
0.1
0.2 0.3
0.4
0.5VICTOREEN
c/m
PHONE
Switch positions are:
• Off
• bat.
• x100• x10• x1
Scale reads from0 to 0.5
VICTOREEN MODEL 493
Ludlum Model 2
01
2 34
5mR/h
ON F
OFF S
HV
OFF
LUDLUMMEASUREMENTS, INC.
SWEETWATER,TEXASMODEL 2
SURVEY METER
BAT
X 10
X 1
X 0.1
Scale Reads from:0 to 5
LUDLUM MODEL 2SURVEY METER
Switch Position Are:• OFF• BAT• X 10• X 1• X 0.1
AUD
What exposure rate is this meter reading?
X 1 _______mREM/hour
X 10 _______mREM/hour
X 100_______mREM/hour
What exposure rate is this meter reading?
X 0.1 ______mREM/hour
X 1.0 ______mREM/hour
X 10 ______mREM/hour
0
0.1
0.30.2
0.4
0.5
mR/h
VICTOREEN 493
LUDLUM MODEL 2
0
2 34
5
1
EXPOSURE RATE
_____ mREM/hour
100 mREM/year (General Public)
500 mREM/year (If Attended Awareness Training)
5 REM/year
OCCUPATIONAL DOSE RATES
BACKGROUND RADIATION DOSE
Source Radiation Received
Radon Gas 200 mREM/year
Daughter Products 28 mREM/year
Food & Water 40 mREM/year
Cosmic Rays 28 mREM/year
Medical Radiation 53 mREM/year
T.V. Consumer Products 7 mREM/year
TOTAL 356 mREM/year
RADIATION DOSES FROM OTHER SOURCES
SOURCE EXPOSURE• One Hour of Jet Flight at 37,000 Feet 2 mREM/hour
• Chest X-Ray or Dental Exam 10 mREM/hour
• Dose to Unborn Child Due to Background 200 mREM/hour
• Pelvic Exam 600 mREM/hour
• Lower GI Series 700 mREM/hour
• Areas of High Background Up to 5000 mREM/year
Biological Effects Due to ExposureCan Be Divided Into Two Groups
EARLY EFFECTS LATE EFFECTS
(ACUTE) (DELAYED)
Blood Count Changes Genetic Damage
Vomiting Increased Cancer Risk
Nausea Shortened Life Span
Death
Some Acute Effects of High Exposure Over a Short Period Are
DOSE (1 week)EFFECT (30 days)
• 30-150 REM Detectable changes in blood counts
• 150-250 REM Nausea and vomiting within 24 hours
• 250-350 REM Death may occur
• 350 REM 50% will Die within 30 days
• 350-600 REM Death will probably occur
• over 600 REM 100% will die within 30 days
Estimated Loss of Life Expectancy From Health Risks
HEALTH ESTIMATES OF DAYS OF
RISK LIFE EXPECTANCY
LOST, AVERAGE
Smoking 20 2370 (6.5 years)
Cigarettes/Day
OVERWEIGHT 435 (1.2 years)
(by 20 %)
RISK CHART CONTINUED
AUTO ACCIDENTS
200 DAYS
ALCOHOL CONSUMPTION
130 DAYS
RISK CHART CONTINUED
HOME ACCIDENTS
95 DAYS
DROWNINGS’
41 DAYS
RISK CHART CONTINUED
SAFEST JOBS
(SUCH AS ………………..)
30 DAYS
NATURAL
BACKGROUND
RADIATION (Calculated)
8 DAYS
RISK CHART CONTINUED
1 REM Occupational Radiation Dose
Calculated (Industry Average Is 0.34 REM/year)
1 DAY
1 REM/year for 30 Years, Calculated
30 DAYS
5 REM/year for 30 years, Calculated
150 DAYS
Everyday Items Containing Radioactive Materials
Scale Found on Oil Field Pipe
Brazil NutsSmoke DetectorsLantern MantlesSome CeramicsSalt Substitutes
ALARA PRINCIPLE
ALARA
stands for AS LOW AS REASONABLY
ACHIEVABLE
REDUCING YOUR EXPOSURE
The three most important safety rules to remember while
working with radiation areTimeTime
Distance Distance
ShieldingShielding
The Effect of Time on Radiation Exposure
EXPOSURE = DOSE RATE X TIME
For Example: 495 mREM per hour
1 HOUR = 495 mREM
2 HOURS = 990 mREM
3 HOURS = 1485 mREM
The Effect of Distance on Radiation Exposure
The Equation for Calculating
Radiation Exposure as a
Function of Distance:
I 1 x ( D1 ) 2 = I 2 x ( D 2 ) 2
OR
I 2 = I 1 x ( D 1 ) 2
( D 2 ) 2
SHIELDINGSHIELDINGDEFINITION
OF
SHIELDINGUsing some material as a
shield to reduce the radiation
exposure.
SHIELD
GAMMA RAYS
SHIELDING MATERIALS
ALPHA PAPER SKIN SEVERAL
INCHES OF
AIR
GAMMA LEAD STEEL GOLD
BETA TIN THIN DEPLETED
ALUMINUM URANIUM
NEUTRONS WATER WAX PARAFFIN