Radiation in a Radioactive World
Nuclear Physics and Engineering
By: Douglas Osborn
Is this what you think when I say nuclear?
Is this only thing something nuclear can do?
Do you think of these people when I say RADIATION?
Do you think of these things as well?
• Food• Space• Utilities• Consumer Products• Medicine
RADIOLOGICAL RADIOLOGICAL FUNDAMENTALSFUNDAMENTALSRADIOLOGICAL RADIOLOGICAL FUNDAMENTALSFUNDAMENTALS
Atomic Structure
Definitions
Types of Ionizing Radiation
Units of Measure
Atomic Structure
Definitions
Types of Ionizing Radiation
Units of Measure
Atomic Structure
• Atomic Structure Particles
• Elements & Isotopes
• Stable vs. Unstable
• Standard Nomenclature
• Ions
Atomic StructureAtomic StructureParticlesParticles
Protons (positive)Nucleus
Proton Neutron
Electron
Nucleus
NP+ e-
Electrons (negative)
Neutrons (neutral)
ElementsElements
• If the number of protons changes, the element changes
• The number of protons in the nucleus determines the element
hydrogenhydrogen
P+
heliumhelium
P+
N
P+
N
lithiumlithium
N N
N N
P+
P+
P+
IsotopesIsotopes• Isotopes - atoms of the same element which
have the same number of protons, but a different number of neutrons
• Isotopes have the same chemical properties; however, the nuclear properties can be quite different
HydrogenHydrogen(protium)(protium)
P+
N
HydrogenHydrogen(deuterium)(deuterium)
P+
N
HydrogenHydrogen(tritium)(tritium)
P+N
Stable vs. Unstable AtomsStable vs. Unstable AtomsIf there are too many or too few neutrons for a given number of protons, the nucleus will not be stable
HydrogenHydrogen(protium)(protium)
P+
e-
STABLESTABLE““Non-Radioactive”Non-Radioactive”
UNSTABLEUNSTABLE““Radioactive”Radioactive”
N
HydrogenHydrogen(tritium)(tritium)
P+
e-N
Standard NomenclatureStandard Nomenclature
XX Repr esent s Repr esent s elementelement
AA# of pr ot ons # of pr ot ons and neut r onsand neut r ons
ZZ# of pr ot ons# of pr ot ons
CoCo6060
2727
IonsIonsIons are atoms with positive or negative charge:
IonsIons
NeutralNeutral
N N
N N
P+
P+
P+
e- e-
e-
PositivePositive
N N
N N
P+
P+
P+
e-
e-
NegativeNegative
N N
N N
P+
P+
P+
e-
e-e-
e-
Definitions• Ionization
• Radiation
• Ionizing vs. Non-Ionizing
• Radioactivity & Radioactive Decay
• Radioactive Half-Life
• Radioactive Material
• Radioactive Contamination
IonizationIonizationThe process of removing electrons from neutral atoms
AND
Free ejectedelectron
RadiationRadiation• Energy released from unstable atoms and
some devices in the form of rays or particles
• Can be either ionizing or non-ionizing
UNSTABLE
ATOMPARTICLE
RADIATION
ENERGY
Ionizing RadiationIonizing Radiation• Radiation that possesses enough energy
to cause ionization in the atoms with which it interacts
• Released from unstable atoms and some devices in the form of rays or particles
- alpha
- beta
- gamma/x-ray
- neutron
0n1
Non-Ionizing RadiationNon-Ionizing Radiation
• Radiation that doesn’t have the amount of energy needed to ionize the atom with which it interacts
• Examples:
- radar waves - infrared radiation
- microwaves - ultraviolet radiation
- visible light
Radioactivity
The process of unstable (or radioactive) atoms becoming stable by emitting radiation. This event over time is called radioactive decay.
NP+P+N
e-
N
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
NP+P+
N
NP+
Large, unstable nucleus
Excess
Energy
Release
d
alpha
beta
gamm
aneutron
Decay ChainDecay Chain
UU2323889292
ThTh2323449090
PaPa2323449191
After 18 decays we arrive at stable:After 18 decays we arrive at stable:
PbPb2020668282
The time it takes for one half of the radioactive atoms present to decay
Example: Co-60 = 5 years
Co-60
Radioactive Half-LifeRadioactive Half-Life
100 atomstoday
50 atomsafter 5 yrs
25 atomsafter 10 yrs
12 atomsafter 15 yrs
Co-60
Ni-60Ni-60
Co-60
Ni-60
Co-60
Radioactive Decay
Develop a model for radioactive decay.
Call it the radioactive decay law.
How do we describe the rate of de-energization?
Observations in Nature: Decay / De-energization
Occurs
Number of Radioactive Nuclides decreases with time
De-energization of a single nuclide is a statistical process
Let’s perform a simulation
Rules• DON’T OPEN the packages until I give you
instructions !!• Need one volunteer from each table group You are
the data runner.• Carefully open the package.• Pour the contents onto your desk – carefully. DO NOT
EAT THEM!• Determine the total number in the bag.
– Report this number to the data runner.• Count those with the “M” UP and return them to the
bag.– Report this count to the data runner.– Eliminate (eat?) those not returned to the bag.
• Calculate and record total counts• Shake the bag and repeat the above.
Counting Period
Counts From Table
Group 1
CountsFrom Table
Group 2
CountsFrom Table
Group 3
Counts From Table
Group 4
Total Counts
One Sigma ErrorNormalized
Value
(Semilog Plot)
(Linear Plot)
Initial Count 844 677 968 685 3174 56.3 1.8 1.000
Count 1 435 331 456 316 1538 39.2 2.5 0.485
Count 2 201 163 250 187 801 0.252
Count 3 96 81 111 86 374 19.3 5.2 0.118
Count 4 53 42 72 51 218 0.069
Count 5 21 28 36 21 106 10.3 9.7 0.033
Count 6 13 12 17 16 58 0.018
Count 7 5 4 12 4 25 5.0 20.0 0.008
Count 8 3 2 2 3 10 0.003
Count 9 2 0 1 0 3 1.7 57.7 0.001
Count 10 2 0 0 0 2 0.001
Count 11 1 0 0 0 1 1.0 100.0 0.000
Count 12 0 0 0 0 0 0.000
N %*100N
N
Graphical Outputs
0
500
1000
1500
2000
2500
3000
3500
1 3 5 7 9 11 13
1
10
100
1000
10000
1 3 5 7 9 11 13
Next Question:What have we observed?
• Decay / De-energization Occurs• Number of Radioactive Nuclides decreases with
time• De-energization of a single nuclide is a statistical
process– This being the case, at the beginning of the de-
energization process when a lot of radioactive nuclides are present, the statistics are much better
– Thus sample counting statistics are much better in the beginning than after most of the nuclides have de-energized
– Why is this?
Counting Statistics: Randomness
• De-energization events are random– Quantity per unit time depends on the total number of
radioactive nuclides present– Thus the quantity decreases with time
• Detection events also are random within the counting media depending on random processes associated with the detector– Probability of penetration into the detector– Probability of interaction in the detector
• Variability and precision of repeated counts can be described with reasonable rigor based solely on the total number of detected events
Counting Statistics – Variability• Variability refers to the distribution of a number of repeated
counts around a true value or a mean value• Repeat counts follow a Poisson Distribution, but when a large
number of repeat counts are taken, the Normal Distribution is a good approximation
• The shape of the Normal curve can be described by using only the mean, , and the standard deviation, s or
• The mean is the arithmetic average of all counts• In the normal distribution, about
– 68% of all counts will fall within one standard deviation– 95% within 1.96 standard deviations– 99% within 2.58 standard deviations
• A property of the Poisson Distribution is that the Standard Deviation is simply the square root of the mean
Precise Example of a Normal Distribution
• Note the symmetry
• Note how the “counts” are distributed
Counting Statistics – Precision• Precision refers to the repeatability of a single count
– How close will a repeated count be to the previous count – or to the next count?
– How close will one count be to the “true mean” of many repeated counts?
– If we have only one count, we expect the true mean is probably different from our one count
• Probability that the true mean lies within specific limits around the count is determined from the shape of the normal error curve, the Normal Distribution– The obtained (measured) count, N, is taken as the mean value, and the
standard deviation, s or , is then the square root of the measured count:
– Thus there is a 68% probability that the true mean lies within one standard deviation, or the square root of the measured count
• The “error” in a given count is then generally considered to be: %100% x
N
NError
Ns
Counting Statistics: Precision Decision• How good is good enough in practice?
– Analyzing the %Error formula clearly says that the more counts you are able to obtain, the more precise your measurement will be.
– The %Error formula states there is a 68% probability that the true value lies within + one standard deviation of the single measured count
– This can also be stated as being within the 68% Confidence Interval– This is a good estimate for general applications
• For more precise work, it’s preferred to be within the 95% Confidence Interval
• And for critical work, you may need to be within the 99% Confidence Interval%100
96.1% x
N
NError
%10058.2
% xN
NError
Counting Statistics – Examples
N NN NN96.1 NN58.2
Sample Confidence Interval Error Estimates68% C.I. 95% C.I. 99% C.I.
Measured Counts, N
20 4.5 0.224 0.438 0.577
50 7.1 0.141 0.277 0.365
100 10.0 0.100 0.196 0.258
200 14.1 0.071 0.139 0.182
1,000 31.6 0.032 0.062 0.082
5,000 70.7 0.014 0.028 0.036
10,000 100.0 0.010 0.020 0.026
40,000 200.0 0.005 0.010 0.013
70,000 264.6 0.004 0.007 0.010
Derivation of the Radioactive Decay Law• Define
A Decay of RateActivity
N(t)dt
dN(t) A
Constant Decay eRadioactiv
• Mathematically
• Need a constant of proportionality
• Why do we have a minus sign in the formula?
N(t)-N(t)dt
dN(t) A
Where N(t) is the number of radioactive nuclei present at time t
Activity (Continued)
N(t)-dt
dN(t) A
Rearrange the terms
N(t)
N
t
0o
dtN
dNdt
N
dNdt
N(t)
dN(t)
t o
t
ooNtN
N
N(t)t
N
N(t)ln ee
N(t)-N(t)dt
dN(t) A
Units of Activity
• Curie– The traditional unit of activity– 1 Ci = 3.7x1010 disintegrations/second– Based on the disintegration rate of 1 gm of Ra-
226
• Becquerel – SI Unit– 1 Bq = 1 dis/sec
Half-life
• Half Life Definition
• Derivation => initial conditions:
amount. initial its of 1/2 todecrease oactivity tor size
sample for the required timeofamount average The
21tt:
2
NN(t) o
1/21/2
1/2tt
oo
t
693.0
t
)2ln(
t)2ln(2
1N
2
N1/21/2
ee
693.0
2/1 t
Mean Lifetime
• Half life is the average amount of time for half of a large sample of nuclides to de-energize
• Mean lifetime is the average (statistical mean) amount of time a single nucleus exists before de-energizing– It can be shown that this is
1
Radioactive Decay on aLinear Scale
Normalizing has been done for illustration only. It is NOT necessary!!
Radioactive Decay on aSemi-Log Scale
Normalizing has been done for illustration only. It is NOT necessary!!
Summary of Concepts
N A Activity
Radioactive Decay Law (Two identical expressions)
Half Life and the Radioactive Decay Constant
1/21/2 t
693.0
t
)2ln(
693.0
2/1 t
t oNtN e t
oAtA e
Radioactive MaterialRadioactive Material
Radioactive material is any material containing unstable atoms that emit radiation
Radioactive ContaminationRadioactive Contamination• Radiation is energy
• Radioactive material is the physical material emitting the radiation
• Radioactive contamination is radioactive material that is uncontained and in an unwanted place
• Exposure to radiation does not result in contamination
Types of Ionizing RadiationTypes of Ionizing Radiation
• Alpha (- particle
• Beta (- particle
• Gamma ( - ray
• Neutron ( - particle
Alpha Radiation (Alpha Radiation ())
CharacteristicsCharacteristics
RangeRange
ShieldingShielding
HazardsHazards
SourcesSources
Particle, Large Mass,+2 Charge
Very Short1 - 2” in air
PaperOuter layer of skin
Internal
Plutonium, Uranium,Americium
Beta Radiation (Beta Radiation ())
CharacteristicsCharacteristics
RangeRange
ShieldingShielding
HazardsHazards
SourcesSources
Particle, Small Mass,-1 Charge
12ft / MeV in air
Plastic, glass,aluminum, wood
Internal and theskin and eyes
Tritium, Sr-90,Fission products
Gamma Rays (Gamma Rays () and X-Rays) and X-Rays
CharacteristicsCharacteristics
RangeRange
ShieldingShielding
HazardsHazards
SourcesSources
No mass, no chargeelectromagnetic
Hundreds of feetin air
Lead, SteelConcrete
Co-60, Kr-88, Cs-137
External SourceWhole Body Penetrating
Neutron Radiation (Neutron Radiation ())
CharacteristicsCharacteristics
RangeRange
ShieldingShielding
HazardsHazards
SourcesSources
Particle withno charge
Hundreds of feetin air
Hydrogenousmaterial -
water, polyethylene
Uranium, Plutonium,Californium
External SourceWhole Body Penetrating
Units of MeasureUnits of Measure
• RadiationRadiation
• RadioactivityRadioactivity
• ContaminationContamination
Energy
Rate
Spread
Roentgen, RAD, REM
dpm, Curie
RadioactivityArea or volume
Roentgen (R)Roentgen (R)• Unit for measuring exposure
• Defined only for ionization in air
• Applies only to gamma and x-rays
• Not related to biological effectsWilhelm Roentgen
1845 -1923Discovered X-rays
RAD (Radiation Absorbed Dose)
• Unit for measuring absorbed dose in any material
• Applies to all types of radiation
• Does not take into account the potential effect that different types of radiation have on the body
REM (Roentgen Equivalent Man)• Unit for measuring dose equivalence
• Most commonly used unit
• Pertains to the human body
• Takes into account the energy absorbed (dose) and the biological effect on the body due to the different types of radiation
Quality Factor (QF)Quality Factor (QF)The QF is used as a multiplier to reflect the relative amount of biological damage caused by the same amount of energy deposited in cells by the different types of ionizing radiation.
remrad x QF = Alpha
20
Neutrons2 - 11
Betas1
Gamma &X-rays 1
Conversion of rem to Conversion of rem to milliremmillirem
1 rem = 1000 millirem (mrem)
500 mrem = rem
0.8 rem = mrem
0.25 rem = mrem
0.50.5
800800
250250
Dose vs. Dose RateDose vs. Dose Rate
• Dose rate is the rate at which you receive the dose
• Dose rate = dose divided by time (rad/hr, mrad/hr)
• Dose is the amount of radiation you receive
Dose Rate
mrem/hr
0 0 00
mrem
1 52
Dose
Measuring RadioactivityMeasuring RadioactivityA measure of the number of disintegrations radioactive material undergoes in a certain period of time
We measure the rate of decay which will lead us to the quantity of radioactive material present
Radioactivity UnitsRadioactivity Units
Basic unit disintegration per minute (dpm) derived from the number of counts
measured by instrument and the efficiency of the instrument
Traditional unit Curie (Ci) 1 Ci = 3.7 x 1010 dpm
Marie Curie1867 - 1934Discovered
radium & polonium
Contamination UnitsContamination UnitsHow spread out is the radioactive material?
Radioactivity
Area or Volume
10 cm
10 cm
dpm
100 cm2
Radioactivity
L X W X H
microcurie
milliliter
BIOLOGICAL EFFECTSBIOLOGICAL EFFECTS
• Background Sources
• Radiation Effects
• Prenatal Exposure
• Risks in Perspective
Background Sources
• Manmade• Natural
• U.S. Average
Background RadiationBackground Radiation
We are constantly exposed to background radiation, from both natural and manmade sources
Background = natural + manmade
Background Radiation SourcesBackground Radiation Sources
RADON
COSMIC
TERRESTRIAL
INTERNAL
MEDICALMEDICAL
CONSUMER PRODUCTSCONSUMER PRODUCTSINDUSTRIALINDUSTRIAL
ATMOSPHERIC TESTINGATMOSPHERIC TESTING
COSMIC
TERRESTRIAL
INTERNAL RADON
NATURALNATURAL MANMADEMANMADE
MEDICAL
CONSUMER PRODUCTSINDUSTRIAL
ATMOSPHERIC TESTING
Natural Background SourcesNatural Background Sources
SOURCE AVG DOSE
28 mrem/yrCOSMIC - outer space
28 mrem/yrTERRESTRIAL - Earth
INTERNAL - our body 40 mrem/yr
RADON - Earth 200 mrem/yr
Manmade Background SourcesManmade Background Sources
SOURCE AVG DOSE
54 mrem/yrMEDICAL
10 mrem/yrCONSUMER PRODUCTS
INDUSTRIAL USES <3 mrem/yr
ATMOSPHERIC Testing <1 mrem/yr
Medical ProceduresMedical Procedures
PROCEDURE AVG DOSE
600 rem to tumorTHERAPY
5.8 rem to headCAT SCAN
MAMMOGRAM 0.4 rem to breast
CHEST X-RAY 10 mrem
Consumer Products
PRODUCT AVG DOSE
1.3 rem/yrTOBACCO PRODUCTS
60 rem/yr - gumsDENTURES
TINTED GLASSES 4 rem/yr - eyes
BUILDING MATERIALS 7 mrem/yr
Radium Dial Factory
U.S. AverageU.S. Average
The average annual doseto the general population
from natural background andmanmade sources is about:
360 mrem.
The average annual doseThe average annual doseto the general populationto the general population
from natural background andfrom natural background andmanmade sources is about:manmade sources is about:
360 mrem360 mrem..
Radiation EffectsRadiation Effects
•Cell Damage
•Cell Sensitivity
•Possible Effects on Cells
•Radiation Damage Factors
•Acute vs. Chronic
•Somatic vs. Heritable
Cell DamageCell Damage
The human body is made up of many organ systems. Each system is made up of tissues. Specialized cells make up tissues. Ionizing radiation can potentially affect the normal function of cells.
Cell Damage (cont.)Cell Damage (cont.)
The method by which radiation causes damage to human cells is by ionization of atoms in the cells. Any potential radiation damage begins with damage to atoms.
Cell DamageCell Damage (cont.)(cont.)Ionizing radiation can directly rupture membranes that surround the cells
Ionizations result in the formation of free radicals which can recombine to form harmful chemicals such as hydrogen peroxide
Cell SensitivityCell Sensitivity
Some cells are more sensitive than others to environmental factors such as:
– Viruses– Toxins– Ionizing radiation
Highest SensitivityHighest Sensitivity
• Actively dividing cells
• Non-specialized cells
• Cells that form sperm
• Hair follicles
• Blood forming cells
Lowest SensitivityLowest Sensitivity
• Less actively dividing cells
• More specialized cells
• Muscle cells
• Brain cells
Possible Effects of Possible Effects of Radiation on CellsRadiation on Cells
• There is no damage
• Cells repair the damage and operate normally
• Cells die
• Cells are damaged and operate abnormally
Radiation Damage FactorsRadiation Damage Factors
• Total DoseTotal Dose
• Dose RateDose Rate
• Type of RadiationType of Radiation
• Area of Body ExposedArea of Body Exposed
• Individual SensitivityIndividual Sensitivity
Total DoseTotal Dose
In general, the greater the dose, the greater the potential for biological effects.
Dose
Effects
Dose RateDose Rate
The faster the dose is delivered, the less time the body has to repair itself.
Type of RadiationType of RadiationCell damage varies with the type of radiation. For example, internally deposited alpha emitters are more damaging than beta or gamma emitters for the same energy deposited.
1 MeV Alpha particle creates 7000 ion pairs per 0.1 cm of travel
1 MeV Beta particle creates 60 ion pairs per 1 cm of travel
vs.
Area of Body ExposedArea of Body Exposed• In general, the larger the area of the body
that receives a dose, the greater the biological effect.
• Extremities are less sensitive than blood forming and other critical organs.
Individual SensitivityIndividual Sensitivity
• Age
The human body becomes less sensitive to ionizing radiation with increasing age; however, elderly people are more sensitive than middle-aged adults.
• Genetic make-up
Some individuals are more sensitive to environmental factors.
Acute vs. Chronic DoseAcute vs. Chronic DosePotential biological effects depend on how much and how fast a radiation dose is received.
Radiation doses are grouped into:
Acute - high dose of radiation received in a short period of time (seconds to days)
Chronic - a small dose of radiation received over a long period of time (months to years)
short periodshort period
longlong periodperiod
high dosehigh dose
smallsmall dosedose
Acute DoseAcute DoseThe body’s cell repair mechanisms are not as effective for repairing damage caused by an acute dose.
– Damaged cells will be replaced by new cells and the body will repair itself, although this may take a number of months.
– In extreme cases the dose may be high enough that recovery would be unlikely.
100 - 200 rem Radiation Sickness
Slight Blood Changes25 - 50 rem
Annual Limit5 rem
Acute Exposure EffectsAcute Exposure EffectsDAMAGEAVG DOSE
> 5000 rem Death Within 2 -3 Days
> 500 rem Gastrointestinal Damage
LD 50-60450 - 600 rem
Blood System Damaged200 - 500 rem
Effects of High-Level Acute Effects of High-Level Acute Doses (Skin/Extremities)Doses (Skin/Extremities)
• Burns
• Necrosis
• Loss of fingers
Chronic DoseChronic DoseA small dose of radiation received over a long period of time.
Typical examples are:The dose we receive from natural
backgroundThe dose we receive from occupational
exposure
Body is better equipped to tolerate chronic doses
backgrounbackgroundd occupationoccupation
alal
Effects of Chronic DosesEffects of Chronic Doses
• Increased risk of cataract formation
• Increased risk of developing cancer
• Somatic effects appear in the exposed individual. Some examples:– Cells may become cancerous– Increased risk of cataract formation– Possible life shortening
• Heritable (genetic) effects appear in future generations– Not yet observed in human populations
Somatic vs. HeritableSomatic vs. Heritable
exposedindividual.
future generations
Prenatal ExposurePrenatal Exposure
• Prenatal SensitivityPrenatal Sensitivity
• Potential Prenatal EffectsPotential Prenatal Effects
Prenatal SensitivityPrenatal Sensitivity
Embryo/fetus cells are rapidly dividing, which makes them sensitive to many environmental factors including ionizing radiation.
Potential Prenatal EffectsPotential Prenatal Effects for Entire Pregnancy for Entire Pregnancy
1.1. Slightly Smaller Head Slightly Smaller Head SizeSize
2.2. Lower Average Birth Lower Average Birth WeightWeight
3.3. Increased Incidence of Increased Incidence of Mental RetardationMental Retardation
4.4. Increased Risk of Increased Risk of Childhood CancerChildhood Cancer
Although no effects were seen in Japanese children conceived after the atomic bomb, there were effects seen in some children who were in the womb when exposed to radiation.
Risks in PerspectiveRisks in Perspective
• Cancer Risk InfoCancer Risk Info
• Comparison of Health RisksComparison of Health Risks
• Occupational Risk ComparisonOccupational Risk Comparison
Cancer Risk InformationCancer Risk Information• Health effects have been observed in humans
at acute doses in excess of 10 rem.
• No increase in cancer has been observed in individuals who receive a dose of ionizing radiation at occupational levels.
• The possibility of cancer induction cannot be dismissed even though an increase has not been observed.
Cancer Risk (cont.)Cancer Risk (cont.)
• Current rate of cancer death among Americans is about 20%.
• An individual who receives 25,000 millirem over a working life increases his/her risk of cancer by 1% to about 21%.
• The average annual dose to DOE workers is less than 100 millirem.
Comparison of Health RisksComparison of Health RisksHealth RiskHealth Risk Days LostDays Lost
3500Unmarried Male
2250Tobacco User
Unmarried Female 1600
Overweight Individual 777
Alcohol Consumer 365
Motor Vehicle Driver 207
100 mrem/yr for 70 yrs 10
Comparison of Occupational RiskComparison of Occupational RiskIndustryIndustry Days LostDays Lost
328Coal Miner
277Farmer
Transportation Worker 164
U.S. Average 74
Manufacturer 43
Radiological Worker 40
EO9
Trades Employee 30
HOW RADIATION EFFECTS YOUR BRAIN
Nuclear Applications
• Food
• Industry
• Medicine
• Space
• Electricity
Food
Industry
• C-14 dating• Smoke Detectors – Am-241• Soft drink bottles - radioisotopes are used to measure and
control how much soda there is in soft drink bottles• Shrink wrap film/plastic insulation on wires - the plastic is
shrunk by radiation instead of using heat, which damages the insulation
• Investigators, police, and other security groups use neutron activation to detect explosives, such as mines, and to detect drugs and weapons
• Companies who process materials such as coal or concrete use neutron activation to analyze the material for quality
Medicine
• Nuclear Medicine – about 1/3 of all medical procedures involve radiation or radioactive materials
• An estimated 10 to 12 million nuclear medicine diagnostic and therapeutic procedures are performed each year in the U.S. alone
• Examples:
– X-rays– NMRI– PET Scans– Radioactive Tracers– Gamma Knife– Cancer Therapy
Space
• Nuclear Jet Engine
• Radioisotope Thermoelectric Generator
• Gas Core Reactor Propulsion
Electricity
• Energy is generated from coal, gas, oil, water, wind, solar, and nuclear. Part of that energy is used to produce electricity. Electrical generation plants use the heat or motion of those primary sources to generate electricity. One way of doing this is by using nuclear power.
Alvin W. Vogtle NPP
Pressurized Water Reactor
Boiler Water Reactor
CANDU Reactor
Liquid Metal Reactor
Gas Cooled Reactor
Three Mile Island
• Middletown, PA
• March 28, 1979
• First meltdown of a full scale nuclear power plant
• Mechanical Failure followed by human error
Chernobyl
• Ukraine
• April 26, 1986
• First commercial reactor to have radiation related deaths
• Human error and lack of safety culture
• 56 deaths directly related to accident (47 emergency workers)
F4 Sled Test
F4 Sled Test Slow Motion
Spent fuel Cask Testing (Train)
Train vs. Truck Cask Results
Spent Fuel Cask Testing (Truck)
Truck Crash Result