Radiation• V. Hassell •No one is sure

about the effects of low doses of radiation

• In every animal species, radiation has been shown to cause mutations

Reactions

Chemical reactions Nuclear Reactions

• Occur when bonds are broken and formed

• atoms remain unchanged, though may be rearranged

• involve only valence electrons

• associated with small energy changes

• reaction rate is influenced by temp, pressure, conc. & catalysts

• Occur when nuclei emit particles and/or rays

• atoms are often converted into atoms of another element

• may involve protons, neutrons, & electrons

• associated with large energy changes

• reaction rate is not normally affected by temp, pressure or catalysts

                                                                                                                              

An atom consists of a nucleus surrounded by electrons.

The electrons are negatively charged.

The atom is held in place by an electric

force of attraction between the positively

charged protons and negatively charged

electrons.

A positively charged electron is called a

positron and can be found in beta

radiation. A positron is also known as an

antiparticle or a particle of antimatter.

An atom that has more or less NEUTRONS than normal or found in nature is called an isotope.

The force of attraction between the protons and neutrons is called the strong force.

Strong nuclear force- acts on subatomic particles to hold the nucleus together

overcomes electrostatic repulsion between protons

To remove a proton or neutron from the nucleus of an atom, we must have a force that is greater than the strong force and therefore, work is required.The amount of work required to remove a proton or neutron is called the binding force.

The strong nuclear force acts on protons and neutrons within a nucleus to

hold the nucleus together.

Unstable protons and neutrons that emit radiation are called radioactive.

Atom- the material stuff is made from- about 105 element

• Transmutation- the

changing of one

element to another

• Transuranium

elements- 93 and greater

radioactive

• Nucleons- the

particles in the nucleus

of the atom (protons &

neutrons)

• Radioactivity- spontaneously decompose

• Radiation- penetrates biological tissues-

leaves no marks, can’t be felt. It breaks down

molecules in cells

• Radioisotopes -isotopes of atoms with

unstable nuclei, emit radiation to attain more

stable atomic configurations

• Radioactive Decay- The strong nuclear force

acts on protons and neutrons within a nucleus

to hold the nucleus together.

• Background radiation is

always present

Emissions

• positron emission-

• radioactive decay

process involving

emission of a positron

• electron capture- occurs

when the nucleus of an

atom draws in a

surrounding electron-

usually from the lowest

energy level

• Alpha decay 42He

• beta decay = 0-1e

• positron emission= 01 β

• electron capture = X-

ray photon

• gamma emission 00γ

Radioactive Decay•Alpha and Beta are

made up of

particles while

gamma is made up

of energy.

The uranium-238 decay series

• one of three

series in which

a radioactive

isotope having

a

long half-life

undergoes a

series of

natural radio-

active changes

and ends as a

stable lead

isotope.

Radiation• V. Hassell

Radiation- continuously decay to form new elements- giving off high-energy radiation. • Ionizing-

• injure atoms

•cancer or

genetic defects

• Certain parts of the

body are more sensitive

• Ionizing Radiation-

Radiation which causes

the things which come in

contact with radiation to

become radioactive.

• Non-ionizing Radiation-

do not cause surrounding

things to become

radioactive

Damage is dependent on• The type of cell and tissues-

somatic/germ, thyroid/hands

• type of rad.-alpha, beta, gamma

• area or volume involved

• total dose & energy of radiation

▫ time for the accumulation of the

dose

When exposed to radiation

▫ Somatic- (body cells) may cause

cancer

▫ Germ cells-(egg & sperm) affect the

formation of children. Birth Defects

• Rad- measure of

radiation dosage

• Rem- measure of the

effect on humans

• Rem-Based on dosage

and damage.

• Rem-Rads X Biological

=Damage Factor

Human Effects of Radiation

Rads Symptoms Results

00-250 fatigue, vomit,hairless, diarrhea

most recovercompletely

400-500 similar symptoms goes awayReturns 3 weeks later

LD-50

2000 rads begins the same-2nd week- very ill

all die

• 1920’s

• Radium-• sold as an over the

counter medication to

treat aches & pains

• In 1932 Eben Byers'

died from using

Radithor starting in

1928 at age 51 &

used several

bottles/ day

• In 1931 his bones

deteriorated,

causing his jaw to

be removed with

other disfiguring

effects, leading to a

notorious death

Radioactive substances

in the 1930’s treated

• Rheumatism

• high blood

pressure

• menstrual

problems

• Depression

• It was used in face

cream, and other

consumer products

1920’s- The Radium Girls

Physicians were baffled and misdiagnosed their conditions as

heart disease and even syphilis.

• the worlds' first mass experience with injury and death

caused by exposure to atomic radiation.

• Judge had economic interest in company- low reward

• Painted watch faces with

radium-based glow in the

dark paint

• Corp Encouraged workers to

use tongues to keep a sharp

point on their paint brushes

• It collected in the bones

causing tumors later-

agonizing deaths, cancer

Fluoroscopes 1920 - 1950• used cutting-edge

technology-the x-ray-to reveal the bones and soft tissue of the foot inside the shoe, ostensibly for a better fit.

• Children loved the quirky machines, going into shoe stores just to stick their feet in the machines: "Seeing the greenish yellow image of your bones was great fun."

Health- x-ray’s used

• 1940s -X-rays with dosages

often 50 to 100 times those

used today.

• As recently as the 1960s

mammograms to detect

breast cancer sometimes

delivered more than 100

times the maximum

allowed radiation dose

today

• routine well-baby pediatric

exams

• to diagnose & treat enlarged

thymus glands

• X-ray exams of pregnant women

- can safely deliver

• monitor lung collapse therapy for

TB.

• As a result, adults and many

children received repeated doses

of ionizing radiation that today

would be considered hazardous.

Human Testing

• $4.8 million paid for human tests in

1940s- Times-Picayune Nov 20 1996

A-4

• U.S. Govt.- injected 12 humans in the

1940’s with uranium & plutonium

without their knowledge in a

radiation experiment.

• See how human body reacts to atomic

bombing

• scientists claim they were terminally

ill anyway and would not survive 10

years

• caused urinary tract infections &

painful osteoporosis (bones looked

like Swiss cheese)

• One woman received 43 X avg

lifetime dose & lived another 38

years.

• Recruited to join the

science club -

received a special diet

• Would get candy every time they

drew blood

• As boys, they were used as guinea

pigs & fed radioactive oatmeal to

test how the body absorbed

nutrients like calcium & iron.

Chain Reactions

• Theses nuclear chain

reactions are self

sustained which means

they do not need additional

energy once the reaction

is started.

• These nuclear chain

reactions is what makes

nuclear reactors and

bombs.

When neutrons split into

smaller particles it is called

fission.

When one neutron splits it

bumps into other neutrons

and causes them to split.

This is called a Nuclear

Chain Reaction.

In fusion, two small nucleus are combined to form a larger nucleus.

•Nuclear fusion is the

source of energy for

the stars, like our

sun.

•To achieve fusion,

nucleus must be

heated to millions of

degrees.

Half-life & chain Reactions

• Chain reaction -a domino

effect

• critical mass- the amount

of a fissionable material

that will support a self-

sustaining chain reaction

• Half-life - A is the time required

for half the atoms in a radioactive

sample to decay.

Every radioisotope has a

characteristic half-life.

Nuclear fission• A neutron strikes U-235, splitting it

& forming new elements -releasing

several neutrons causing a chain

reaction & releases a lot of energy

• the splitting of a heavy atom like

Uranium or Plutonium.

• One pound(U-235)=1000 tons coal

• Problems

• Needs tritium (radioactive), which

is not abundant and difficult to

contain.

• It causes embrittlement

• High Thermal Pollution

Nuclear power plants

• control fission through neutron

moderation and neutron absorption

• use nuclear fission to generate steam.

• steam is used to drive turbines that

produce electrical power.

• Embrittlement

• - the metals making up the nuclear power

plant become brittle because of neutron

bombardment and makes it unsafe

• Decommissioned

• the shutting of a plant down by sealing

the entire containment building for an

indefinite period of time.

Coolant- usually water- removes heat to keep the fuel rods and other materials from melting

Core- contains of fuel rods packed with U-235 as the fuel

Control rods- of cadmium or boron- absorb neutrons &

regulate reaction

Moderator- water, graphite or heavy water is used to slow

down the neutrons emitted by the fission process

Types of Reactors

•Fission-Fuel-Uranium/Plutonium byproduct-radiation

•Fusion- Fuel = Hydrogen, Byproduct =helium(inert, nonradioactive)

•Breeder- creates more fuel than it consumes

no longer considered a good choice for the future b/c

• Construction takes longer,

needs multiple safeguards, must

meet higher safety standards.

• expensive & relatively short

supply

• Biggest Default on public bonds

• fears

• Medical affects

• China Syndrome

• - a loss of coolant accident-

After 45 sec, the core

temperature will rise to 1480

degrees C.

• It can react to produce

• Hydrogen gas -explosive.

Fear-

A MAJOR NUCLEAR ACCIDENT ANYWHERE IS A

NUCLEAR ACCIDENT EVERYWHERE

3 Mile Island

• human error, blocked

valves, broken pumps-

• The reactor was partially

uncovered & 50 % melted.

Unknown amounts of

radiation escaped.

• 50,000 were evacuated.

• The Nuclear Regulatory

Commission (NRC)

required 300 safety

improvements to

nuclear reactors after

the incident

Leaks-

• From Weapons Plants-

Hanford, WA &

Savannah River

• 3 Mile Island Nuclear

Power

• Chernobyl

• Insects radioactive, but don’t

let it bug you. Times Picayune- Oct, 22, 1998

• Washington state- close to Hanover Nuclear power plant

• officials claim radioactivity is slight & no threat

• ants, flying insects, tumble weeds, flies, gnats

• might indicate an increase in radioactivity in soil or

ground water (claim it is from radioactive garbage)

Chernobyl- 1986

•A massive explosion blasted tons of hazardous materials high into the air

•By 1994 it caused 8,000 premature deaths

One of the great failures of Chernobyl was that the government of the Soviet Union did not immediately take steps to protect the public, especially the vulnerable—children and pregnant mothers—from potential radioactive fallout.

Cesium 137 is man made and does not occur naturally in nature.

• The March 2011 tsunami off Japan flooded the

Fukushima Dai-Ichi nuclear plant, causing

radiation-contaminated water to spill into the

Pacific. Airborne radiation was detected in milk

and rainwater in the U.S. soon afterward. But

things move much more slowly in the ocean.

• http://

www.scmp.com/news/asia/article/1443158/japanese-investigator-says-lessons-fukush

ima-disaster-ignored

Fukishima Japan- An earthquake caused a tidal wave that led to reactor damage.•http://

www.ne.anl.gov/jp/fukushima-facts-and-myths.shtml

•BBC ghost town/dead zone video 2014•http://www.bbc.com/news/world-asia-2652

4772

Types of nuclear waste

• low level – slightly

contaminated- clothing

high level- spent reactor

fuel rods

disposal of radioactive

wastes and thermal

pollution are unsolved

problems.

• Nuclear Waste

• no safe method of long term disposal and no

permanent disposal site in the U.S.

• used to produce nuclear weapons

• we purchase it from other countries.

• Spent fuel rods removed from nuclear cores

are stored in on-site pools

• Outdoor Cement Casks store spent nuclear

rods- built to withstand missiles,

earthquakes, etc.

Dry Cask storage-25 tons for 10,000 years

Atomic Bombs

• uncontrolled release of nuclear energy

• ceases when all fissionable nuclear material is

used up.

• 1945-1st bomb test & Hiroshima – Fission reaction

• Nagasaki-killed over 200,000

• testing-atomic veterans/ships

• http://www.youtube.com/watch?v=yjiWBkiBZQU

Atomic Blast

• Heat rays cast a permanent

shadow of a bridge rail

• Person’s shadow left behind

where they were sitting

Hiroshima, Japan

Atomic Blast

• Temp several million o C

• heat- 3 sec (1.5 miles-

clothes spontaneously

combust, wood burns

from the inside out

• Pressure (Shock wave)

• Vacuum

• Depends on if it is an air

blast or on the surface

• Duck & Cover

Drills

• run in the 1960’s

in school in the U.S.

Bay of Pigs

(Cuban Crisis)

Atomic Veterans

• Difficult to ID whose who should be medically tested

• Screening might do more harm b/c cancers often are benign causing needless worry

March 1, 1954-• 23 atomic tests 1000 X more powerful than Hiroshima

• 1946-58 effect of radiation on ships, planes, goats, etc.

• Fallout landed on Rongelap Atoll-100miles off

• 2 days later -radioactive snow covered it

• 167 natives left - declared safe- returned & evacuated

• still radioactive -planning on clearing land to scrape &

spread potassium over it

• People evacuated, returned & left due to radioactive

illnesses.

•  The atoll's soil remains contaminated by radioactive

cesium, a metal by-product of the blast. For that reason

visitors are told not to eat coconuts or anything else grown

on the island. All of Bikini's food is imported.

• In 201o, Bikini Atoll is still deemed uninhabitable because

of dangerous radiation levels. The native citizens remain

displaced on nearby islands, compensated by the US

Government.

• The biggest draw for divers is the vast number of sunken

American and Japanese WWII ships that were used as

targets (including the only submerged aircraft carrier in the

world). Many also enjoy seeing the abundant species

of three-eyed fish

H-Bomb accidentally fell in 1957

• A 42,000 pound hydrogen bomb

accidentally fell from an Air Force

plane 29 years ago

• no one injured- crater 12 feet deep,

25 ft in diameter

• minor radioactive contamination

• more than 10 megaton yield? 1

megaton=1 million tons of TNT

• 625 X more than Hiroshima

• soldier fell against controls & it

released it?

Suicide squads reportedly were

trained to use nuclear backpacks

•Dallas Morning News- Wed, July 27, 1994 pg. 4A Supposed to

deliver, arm and then watch the

device until it went off to ensure

that enemy forces did not interfere

with the explosion

• “Although demolition units likely

were to perish, , delay in the onset

of effects...may permit some

personnel to remain effective long

enough to influence a specific

operation; the training manual

states.

In fusion, two small nucleus are combined to form a larger nucleus.

• Process -powering the

stars

• Millions of degrees are

needed for the reaction

to occur-

• cause a containment

problem due to the high

temperature and

pressure needed.

Geiger Counter-• particles in tube are

ionized by radiation

striking them. The more

radiation, the more

ionization and the

stronger the current

which flows through the

tube. A counter produces

clicks as indicator of the

radiation around

Geiger Counter Demo

• Radiation may be

detected with a

Geiger counter or

a scintillation

counter.

• A film badge

monitors radiation

exposure of

individuals who

work with

radioactive

materials.

Measuring RadioactivityElectroscope

Cloud Chamber-

• detects electric charge- leaves repel when charged radiation causes charged air (ionization)

• alcohol in container with dry gas- ions formed (alpha produce a visible track in the cloud chamber

Bubble Chamber- •liquid hydrogen at its

boiling temp with reduction in pressure cause bubbles to appear along the path of the particle. Condensation trails- (like path of jet air craft) are formed.

Hadron Collider

•The worlds largest•Lies in a tunnel

27 kilometers (17 mi) around and 175 meters down. Franco-Swiss border near

•It is designed to collide opposing particle beams at high energy

•Hadron refers to particles composed of quarks

Particle Accelerators

•Use magnetic fields and electromagnetic waves to accelerate charged particles

•cyclotron- electromagnetic devise for accelerating protons and deuterons in a spiral path (electrodes switch charges)

•deuteron- deuterium nuclide

Tracers- radioactive material whose path may be followed•Detect ground water movement through

soil•paths of industrial pollutants in air &

water•shifting of sand along coastline• test of durability of components & ID

structural weaknesses of equipment•medicine- diagnosis & treatment• irradiation of food-long term storage w/o

refrigeration (kills bacteria & molds which cause spoilage.

Photosynthesis• Green plants absorb carbon in the form of carbon

dioxide. A % of this is C-14. Once the plant dies, the photosynthesis stops and no more CO2 is absorbed. The decay of C-14 continues. By measuring the amount of radioactivity of C-14 a once-living plant yields- its age can be determined. The half-life of C-14 is 5700 yrs.

• The age of the earth is determined by measuring the quantity of uranium-238 and of lead or helium found in minerals. The amounts of carbon-14 and carbon-12 found in organic remains are used to estimate their ages up to 60 000 years.

Radioisotope target organ

• Chromium 51 spleen• Iodine 131 thyroid gland, lungs,

kidneys• gallium 67 lymph glands• selenium 75 pancreas• technetium 99 brain, lungs,

liver, spleen, bones

• Iron -59 used to produce this image of a patient’s circulatory system

Isotope depends onDosagehalf-lifechemical activity

PET-• positron emission

tomography- expensive- requires radionuclides w/short half-life's

• must maintain a cyclotron to produce as needed

Synchrotron-

a ring of focusing

electromagnets- 2 km/hr.

betatron- circular

accelerator- electrons for

bombardment or production

of high energy x-rays

linear accelerator- doesn’t

use magnetic fields

Medical diagnosticsSPECT- MRI

• single photon emission computed tomography diagnose malfunctions more accurately than X-ray move common place than PET

• Magnetic Resonance Imaging

A recent Cincinnati Enquirer headline read SMELL OF BAKED BREAD MAY BE HEALTH HAZARD

• The article went on to describe the dangers of the smell of baking bread.

• The main danger, apparently, Is that the organic components of this

• aroma may break down ozone (I'm not making this stuff up) .I was horrified. When

• are we going to do something about bread-induced global warming? Sure. we

• attack tobacco companies, but when 1s the government going to go after Big Bread?

• Well, I've done a l1ttle research, and what I've discovered should make anyone think twice

1: More than 98 percent of convicted felons are bread eaters.

2: Fully HALF of all children who grow up in bread -consuming households score below average on standardized tests.

3: In the l8th century, when virtually all bread was baked in the home, the average life expectancy was less than 50 years; infant mortality rates

were unacceptably high; many women died in childbirth; and diseases such as typhoid, yellow fever and influenza ravaged whole nations.

4: More than 90 percent of violent crimes are committed within 24 hours of eating bread.

5: Bread is made from a Substance called -dough.- It has been proven that as little as one pound of dough can be used to suffocate a mouse. The average American eats more bread than that in one month!

6: Primitive tribal societies that have no bread exhibit a low occurrence of cancer, Alzheimer's. Parkinson's disease and osteoporosis.

7: Bread has been proven to be addictive. Subjects deprived of bread and given only water to eat, actually begged for bread after only two days.

Fusion• Fusion Reactor

Experiments Reveal Details of Cooling Process

• http://www.laboratoryequipment.com/videos/2013/04/fusion-reactor-experiments-reveal-details-cooling-process