Nuclear Engineering ANS Outreach
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Transcript of Nuclear Engineering ANS Outreach
What is Nuclear Engineering?
American Nuclear SocietyPurdue Student Chapter
1
This is it, right?
2
What is Nuclear Engineering?
Nuclear engineering is harnessing the power of the atom to do work
3
Early History
450 BC: Democritus termed atomos as the “smallest indivisible particle of matter”Early models of the atom:John Dalton, 1803: ‘Cannonball’ like atomsJJ Thomson, 1904: Plum pudding model
After his 1897 discovery of the electron
Discovering the Nucleus
Bad news for ThomsonPlum pudding was disproved by Rutherford with his classic backscattering experimentThis proved the existence of the nucleus in 1911
Discovering Electrons
Enter Niels BohrElectrons must have energy levelsProposes planetary model of the atom based on Rutherford’sMath checks out for light elements
Discovering Radiation
1896: Henri Becquerel discovers that uranium emits gamma rays
In the following years, Marie Curie finds more radioactive elements, like radium
Discovering Fission
Hahn and Meitner discover fission in 1938
Fermi conducts first successful chain reaction at the University of Chicago in December, 1942
First Nuclear Weapons
Manhattan Project (1945)
“Little Boy” – uranium device dropped on Hiroshima
“Fat Man” – plutonium device dropped on Nagasaki
First Nuclear Power
1951: EBR-1 in Idaho is first reactor to generate electricity
1957: Shippingport Reactor in Pennsylvania is the first commercial nuclear power plant in U.S.
RadiationNuclear Engineering is…
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The Atom
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electronsprotonsneutronsnucleus
γ
Gamma Radiation
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Alpha Radiation
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α
Beta Radiation
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β
Neutron Radiation
16
n
Radiation Damage
How does radiation damage happen?
4 kinds of radiation: Alpha, Beta, Neutron Gamma
¾ are PARTICLES Primary mode of
damage: COLLISIONAL ~ Billiard Balls
Damage is a function of: KINETIC ENERGY TRANSFER [1
]
Biological Radiation Damage
The damage process Incident particles
interact with the material
Cause ionizations Change/Destroy
Molecules Biological materials
do not have a crystal lattice to add strength Much more readily
damaged
[3]
Biological effects, continued [4] With incident radiation cells can be:
Unchanged Damaged▪ Damage can be repaired, can return to normal
functioning▪ Damage can be repaired, cell functions are off-normal▪ Can damage other cells, can reproduce unhealthy cells,
can be unable to reproduce
Killed The number and type of cells damaged or
killed determines the impact of a radiation does to biological materials
How do you protect yourself from radiation?
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ShieldingDistanceTimeAmount
Radiation Shielding
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n
β
α
γ
paper aluminum lead atom
How do you detect radiation?
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Answer: Detectors
There are many types of detectors
Today we will use a Geiger-Müller Counter
Basic concept: Radiation enters chamber Ionizes the gas Creates ions that are
attracted to the wire
Geiger Counter
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click!
Radiation is everywhere
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earth
concrete
x-rays
cosmicrays
food
Quantum mechanics
Want to split an atom? Look at your Television!
CRT (giant TV’s) take electrons and speeds them up.
They’re smashed into phosphor molecules on the screen
Collision releases energy and lights the TV screen
http://science.howstuffworks.com/atom-smasher2.htm
How a high- energy accelerator works
Differences from the TV? Particles are bigger Particles move faster
(near speed of light!) Move in a circular
track Collision results in
more subatomic particles
How it works? Particles are
accelerated using EM waves like a surfer riding a swell
The more energetic the particle, the easier it is to see the structures.
Example? If you hit a cue ball in pool and make it go faster the rack of balls will scatter faster and further.
http://science.howstuffworks.com/atom-smasher2.htm
What is detected?
There are many types of detectors
Things that can be detected: Number of particles Energy Mass
http://science.howstuffworks.com/atom-smasher9.htm
Nuclear energy
Nuclear Engineering is…
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U-235U-236
neutrons
Tc-99
I-135
Fission
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Fission Chain Reaction
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H-3
H-2αn
Fusion
BWR: Boiling Water Reactor
Nuclear Power Plants in the U.S.
Nuclear Power Facts
Even though no new plants have been built, the percentage of US electricity generated has increased!
Radiation from nuclear power has never caused a death or cancer in the United States
A nuclear power plant cannot undergo a nuclear explosion
Inertial Confinement Fusion
Magnetic Confinement Fusion
Challenges for Nuclear Fusion Power
Materials challenges First wall High-power superconducting magnets High energy neutron fluxes▪ Lithium blankets, neutron absorbers
Control of plasma We can do this if we solve the materials
challenges
Nuclear Fuel Cycle
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Mining & Milling – Uranium Oxide (U3O8)
Conversion to UF6Enrichment to 3-4% U-235Fabrication in to Fuel Assemblies Burned in ReactorStorage in Spent Fuel PoolDry Cask StoragePermanent Underground StorageReprocessing to Make New Fuel
Energy Equivalence
1 Uranium Pellet
3 Barrelsof Oil
1 Ton of Coal17,000 Cubic Feetof Natural Gas
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Energy Equivalence
1000 MWeNuclear Power Plant
1 km2
1000 Windmills
100 km2
Solar Cells
5000 km2
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Nuclear Power vs. Nuclear Bomb
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U-235
U-238
Solving Problems
Nuclear Engineering is…
Radioactive Waste
Low-level waste: items that have become contaminated or radioactive Contaminated protective shoe covers and
clothing Wiping rags, mops, filters, tools Luminous dials Medical tubes, swabs, injection needles,
syringes, and laboratory animal carcasses and tissues
Low-level waste is disposed underground
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Spent Nuclear Fuel
About 1/3 of the core is removed every 12-18 months
Spent fuel is extremely radioactive!
Stored in spent fuel pool at plant for 5 years to cool
Moved to dry storage once pool is full
Currently have 60,000 metric tons of spent fuel (covers a football field, 7 yards deep)
What are we going to do with it?
Nuclear Non-Proliferation Nuclear material from the nuclear fuel cycle
could be diverted to a weapons program Atomic Bomb▪ Need to chemically separate or enrich material▪ Takes a lot of time, money, and technology
Dirty Bomb: disperse radioactive materials International Atomic Energy Agency
(IAEA) Facilitates peaceful use of nuclear technology Protects nuclear material around the world and
verifies that it is not diverted
Homeland Security
CIA works with IAEA to detect nuclear weapons
Seismic monitoring can detect nuclear weapons testing (like in North Korea)
Portal radiation monitors scan incoming cargo
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Nuclear Medicine
What is Nuclear Medicine?
Nuclear Medicine is a branch of medicine that uses radioisotopes to: diagnose, treat, and track diseases in the human body.
Basic Principle: Certain organs and tissue uptake specific
isotopes or chemical compounds Radioisotopes are combined with
pharmaceuticals that will be absorbed in the tissue or organ in question
Diagnose
Imaging based on function and physiology, not solely on anatomy.
Scan types: Planar SPECT: Single Photon Emission
Computed Tomography PET: Positron Emission Tomography
CAT and MRI scans do not use radioactivity
Abnormal PET/CT
Treatment
Radiopharmaceuticals emit ionizing radiation that travels a short distance in the body
Minimizes unwanted side effects and damage to noninvolved organs and tissues
Some Examples: Iodine-131 : hyperthyroidism Yttrium-90: Lymphoma Strontium-89: bone pain treatment
How it Works
IMAGING
Administration IV Inhaled as a gas Swallowed
The tracer accumulates, and then is imaged with gamma cameras
TREATMENT
Administration IV Inhaled as a gas Swallowed
The tracer accumulates, and then decays, delivering localized dose
What happens after invivo treatment?
Treatments are generally outpatient treatments
The treatment will continue to decay while in your body
Isotopes are choose with have short half lives, so they decay quickly
Your body also has a natural “filtration system” that removes the tracers from your system, known as a biological half-life.
Applications of Nuclear Technology
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Space Application: Power Radioisotope Thermoelectric
Generators (RGT) Long life power source
(months-100yr) Alpha decay heats
thermocouples for electricity
New HorizonsMission to Pluto
Apollo 14
RTG
Space Application: Power Fission Surface Power
Source Fission Reactor to be used on
the surface of the moon or mars
Would be used to power a permanent outpost
Liquid metal coolant used instead of water
Space Applications: Propulsion Nuclear Thermal
Rocket Engines Propellant gas
(hydrogen) is heated in a reactor and is pushed through a nozzle
Ion Propulsion Ionized hydrogen gas
(protons) are accelerated by a strong electric field powered by a nuclear reactor or RTG
NERVA rocket
Ion Engine
Consumer Products: Smoke Detectors
Smoke Detectors An alpha emitter
(Am-241) is used in smoke detection circuit
Alphas ionize an electric plate
Smoke stops ionization of the plate which sets off alarm NOTE: To properly dispose of a smoke detector, just send it back to the manufacturer.
Consumer Products: Self-Powered Lighting Beta emitters
(such as Tritium) are combined with a phosphorescent material to produce light Can make lights
that run continuously for 20 years
Example products
Watch dials
Emergency signs
Gun scopes
Consumer Products: Irradiated Gemstones Color in gemstones is caused by small
imperfections in the crystal structure Most types of radiation (especially
neutrons) can effectively change the color of a gemstone to something more desirable
Manufacturing: Radiation Hardening
Radiation causes small defects in a material which hardens it
Gamma radiation is most commonly used because it can penetrate deep into materials
Examples: Polymerization of
plastics Protective coatings
for hard wood floors
Food Irradiation
Food irradiation: Does not “kill” or spoil the food (it is already
dead) Does not make the food radioactive Does kill living things in the food (bacteria,
viruses) Irradiation can prevent:
Food borne diseases Food infestation Food contamination and spoilage
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Imaging
Neutron radiography Neutron imaging can be
used to find cracks in thick materials such as bridges or aircraft wings
Neutrons can also provide clearer images than X-rays
• Ground Imaging– Neutrons are used in oil
well logging– Neutrons are also used
to determine the water concentration of soil before building heavy structuresNeutron image X-ray image
Careers Opportunities
More nuclear professionals are needed
The demand exceeds the supply of graduates trained in nuclear science and technology
Many nuclear professionals are retiring and need to transfer their knowledge to the next generation of experts.
Scholarships, awards, and honors exist for student education and research
Nuclear Engineers have the 3rd highest median income among the engineering professions at $102,000/year
Government and National Security
Nuclear Regulatory Commission Department of Energy
Research at national labs Homeland security
Central Intelligence Agency NASA
Military Navy Department of
Defense Naval reactor
research and development
Nuclear Power Plants
Reactor Operator Core Designer Safety Analysis Radiation
Protection
Power Industry
Reactor vendors Engineering firms Designer, core
analysis, engineering support of nuclear power plants
Medical
Hospitals or research Nuclear Pharmacy (radioactive tracers) Radiation Therapy (cancer) Positron Emission Tomography (PET) Boron Neutron Capture Therapy (BNCT) DNA Sequencing
Purdue Nuclear Engineering
Research Areas Ultraintense Laser Science and Technology Center for Materials Under Extreme
Environment Radiation Materials and Surface Interactions Nuclear Detection and Remote Sensing Radiation Shielding for Space Applications Thermal Hydraulics and Reactor Safety Fuel Cycle and Waste Management Hydrogen and Fuel Cell Nuclear Systems Simulation Applied Intelligent Systems Reactor Fusion Reactor Physics
First Year Engineering
Introduction to Engineering Calculus I and II Chemistry I and II Physics I and II English Communications Computer Science
Nuclear Engineering Curriculum Math (4) Intro to Nuclear
Engr. Mechanical Engr.
(3) Radiation Lab Materials (2-3 &
Lab) Neutron Physics
(2) Thermal-
Hydraulics (2) Fluid Mechanics
Lab
Linear Circuit Analysis
Reactor Lab Nuclear Power
Systems Nuclear Reactor
Theory Colloquium Series Technical Electives
(6) General Electives
(6) Senior Design (2)
PUR-1
• Only nuclear reactor in Indiana• Used for
research and teaching• Get to operate
it senior year!
Questions?Nuclear Engineering is…
?
Sources
American Nuclear Society U.S. Department of Energy U.S. Nuclear Regulatory Commission Nuclear Energy Institute International Atomic Energy Agency American Wind Energy Association World Nuclear Association NASA
Three Mile Island Accident – Pennsylvania 1979 Cooling malfunction
caused part of the core to melt, destroyed reactor
Some radioactive gas was released a couple of days after the accident, but not above background levels to local residents
No injuries or adverse health effects
http://www.teachersparadise.com/ency/en/wikipedia/t/th/three_mile_island.html
Chernobyl Accident – Ukraine 1986 Flawed reactor design, operated by
inadequately trained personnel, unsafe operation
Steam explosion and fire released 5% of the radioactive reactor core into the atmosphere
28 people died within four months from radiation or thermal burns, 19 have subsequently died, and about 9 deaths from thyroid cancer: total 56 fatalities
Damaged reactor currently contained in sarcophagus
New sturdy steel containment to be built soon http://blog.kievukraine.info/uploaded_images/5436-
708397.jpg