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