Chapter 4: Discovering the Secrets of the Nucleus From a Photographic Mystery to the Atomic Bomb © 2003 John Wiley and Sons Publishers Courtesy Fermilab/Peter

Chapter 4: Discovering the Secrets of the Nucleus

From a Photographic Mystery to the Atomic Bomb

© 2003 John Wiley and Sons Publishers

Courtesy Fermilab/Peter Arnold Inc.

Brain images with 123I-labeled compound

Figure 4.1


Antoine Henri Becquierel.


Courtesy Culver Pictures, Inc.

Marie Sklodowska Curie with her daughter, Irene.


Courtesy The Center for the History of Chemistry

Radioactive Isotopes

• A radioactive isotope has an unstable nucleus and emits radiation to become more stable.

• Isotopes of elements may be stable or unstable.

Alpha Decay

• When a radioactive nucleus emits an alpha particle, a new nucleus results.

• The mass number of the new nucleus is 4 less than that of the initial nucleus.

• The atomic number is decreased by 2.

Equation for Alpha Decay

Write an equation for the alpha decay of Rn-222. 222Rn new nucleus + 4He 86 2

Determine the mass and atomic numbers of the new nucleus.

Mass number: 222 – 4 = 218Atomic number: 86 – 2 = 84Symbol of element 84 = Po

Complete the equation with the new symbol:222Rn 218Po + 4He

86 84 2

Beta Decay

A beta particle Is an electron

emitted from the nucleus.

Forms when a neutron in the nucleus breaks down.1n 0e + 1H0 -1 1

Figure 4.5: Radioactive decay of tritium.


Figure 4.6: Radioactive decay of carbon-14.


Potassium - 42 is a beta emitter.42K new nucleus + 0e19 -1

The atomic number of the new nucleus increases by 1.

Mass number : (same) = 42Atomic number: 19 + 1 = 20Symbol of element 20 = Ca

The nuclear equation is42K 42Ca + 0e19 20 -1

Writing An Equation for a Beta Emitter

Ernest Rutherford discovered α rays and β rays.


Courtesy C.E. Wynn-Williams

Write the nuclear equation for the beta decay of Co-60.

60Co 27

Learning Check

Write the nuclear equation for the beta decay of Co-60.

60Co 60Ni + 0e 27 28 1

beta particle

Solution

• Gamma radiation is energy emitted from an unstable nucleus indicated by m.

• In a nuclear equation for gamma emission, the mass number and the atomic number are the same.

99mTc 99Tc + 43 43

Gamma Radiation

Summary of Radiation

Producing Radioactive Isotopes

• A nucleus is converted to a radioactive nucleus by bombarding it with a small particle.

What radioactive isotope is produced when a neutron bombards cobalt-59?

59Co + 1n ???? + 4He 27 0 2

Learning Check

What radioactive isotope is produced when a neutron bombards cobalt-59?

mass numbers

= 60 = 6059Co + 1n 56Mn + 4H e

27 0 25 2

= 27 = 27atomic numbers

Solution

Figure 4.2: The penetrating power of radiation.


Figure 4.3: Notation showing atomic number, mass number, and charge.


Gamma ray analysis of a fitting for a medical device shows it to be free of flaws.


Courtesy Amersham Technology

Figure 4.4: The components of α rays, β rays, and γ rays.


Figure 4.7: The sequence of radioactive decay from 238-92U to 206-82Pb.


Figure 4.8: A typical fission reaction of U-235.


Nuclear Fission

• When a neutron bombards U-235, an unstable nucleus of U-236 undergoes fission (splits) to form smaller nuclei such as Kr-91 and Ba-142.

Chain Reaction

A chain reaction occurs when a critical mass of uranium undergoes fission so rapidly that the release of a large amount of heat and energy results in an atomic explosion.

Lise Meitner interpreted Otto Hahn’s experimental observations as confirmation that he had split a uranium nucleus.


Courtesy Bibliothek Und Archiv zur Geschichte der Max-Planck-Gesellschaft, Berlin

Figure 4.10: Enrichment by gaseous diffusion.


Uranium-235, a source of nuclear power.


Courtesy US Department of Energy

Figure 4.11: The operation of fission bombs.


The world’s first atomic explosion, July 16, 1945 at Alamogordo, New Mexico.


Courtesy Scott Camazine/Photo Researchers

J. Robert Oppenheimer and Leslie Groves at the remains of the tower used in the test of the first atomic bomb.


Courtesy Bettmann/Corbis Images

Remains of a building after the explosion of the uranium bomb at Hiroshima, August 6, 1945.


Courtesy Shigeo Hayashi

A flare ejected from the surface of the sun.


Courtesy NASA

• Fusion involves the combination of small nuclei to form a larger nucleus.

Nuclear Fusion

Indicate if each of the following is

1) nuclear fission or 2) nuclear fusion

___ A. A nucleus splits.

___ B. Large amounts of energy are released.

___ C. Small nuclei form larger nuclei.

___ D. Hydrogen nuclei react.

___ E. Several neutrons are released.

Learning Check

Indicate if each of the following is

1) nuclear fission or 2) nuclear fusion

1 A. A nucleus splits.

1, 2 B. Large amounts of energy are released.

2 C. Small nuclei form larger nuclei.

2 D. Hydrogen nuclei react.

1 E. Several neutrons are released.

Solution

Albert Einstein, he discovered the equation that relates mass and energy.


Courtesy AP/Wide World Photos

Nuclear Power and Its Wastes

Divan Fard

This Way to Sustainability V Conference at California State University, Chico

November 5-8, 2009

Acknowledgement

• Roy Gephart; Jim Amonette, Elsa Rodriguez, Jose Marquez (Pacific Northwest National Laboratory Richland, Washington USA)

• Department of Energy• AAAS• NRC• IAEA• Institute for Energy and Environmental Research• American Nuclear Society• Green Peace• Physicians for Social Responsibility

What to read

http://www.helencaldicott.com/books.htm

Dr. Helen Caldicott’s message :

• “Every male in the Northern Hemisphere has a tiny load of plutonium in his testicles from nuclear (weapons) testing days,” Caldicott said, as men in the audience squirmed.March 24, 2011 8:45 p.m.

• http://www.metronews.ca/ottawa/business/article/813044--new-reactors-mean-more-cancer-critic

http://www.metronews.ca/ottawa/business/article/813044--new-reactors-mean-more-cancer-critic

Wind, water and solar technologies can provide 100% of the world’s energy, eliminating all fossil fuels.

Scientific American November 2009Mark Z. Jacobson, Mark A. Delucchi

http://www.scientificamerican.com/article.cfm?id=a-path-to-sustainable-energy-by-2030

Save 2.5 million to 3 million lives a year Halt global warming, Reduce air and water pollution Develop secure, reliable energy sources

Nearly all with existing technology and at costs comparable with

what we spend on energy today http://www.sciencedaily.com/releases/2011/01/110126091443.htm

ScienceDaily (Jan. 27, 2011)why wouldn't you do it?

http://www.sciencedaily.com/releases/2011/01/110126091443.htm

Key Concepts

• The authors’ plan calls for 3.8 million large wind turbines, 90,000 solar plants, and numerous geothermal, tidal and rooftop solar energy panels.

• The cost of generating and transmitting power would be less than the projected cost per kilowatt-hour for fossil fuel and nuclear power.

Nuclear Industry

• Global warming is a reality and fast action is needed.

• Nuclear industry sees opportunity to promote itself .

One pound of Uranium produces one million times more energy than one pound of coal.

Claimed Economic Advantages

Emissions Free

• Nuclear energy annually preventsmillions tons of sulfur

millions tons of nitrogen oxide

millions metric tons of carbon

Nuclear Fission

1934-Otto Hahn discover fission1938– Scientists study Uranium nucleus

History of nuclear power1934-Otto Hahn discover fission

1938– Scientists study Uranium nucleus

1941 – Manhattan Project begins

1942 – Controlled nuclear chain reaction

discovere

1945 – U.S. uses two atomic bombs on Japan

1949 – Soviets develop atomic bomb

1952 – U.S. tests hydrogen bomb

1955 – First U.S. nuclear submarine

The legacy of Hiroshima

• August 6, 1945: city of Hiroshima the victim of the 1st nuclear weapon 140,000 killed.

• August 9, 1945: Nagasaki the victim of the 2nd

nuclear weapon; 75,000 killed.

• Massive, systematic attacks on civilian populations becomes permissible means of waging war .

Concept of Half-Life

Decay Series

Types of Emissions

Units of Radioactivity

• Curie (Ci) = 3.7X1010 disintegration /Second

Fuel rods are usually 4m long and 15cm in diameter

Nuclear Fuel Cycle

• Uranium mining and milling

• Conversion and enrichment

• Fuel rod fabrication

• POWER REACTOR

• Reprocessing, or

• Radioactive waste disposal

Uranium enrichmentUranium ore is 0.7 %U-235

– Fuel Rod: U-235 3%– Weapons grade: U-235 90%Enrichment needs CFC-114

• CFC-114 is 10,000-20,000 times heat trapping than CO2

The uranium enrichment plant in Paducah, Ky., and its sister facility in Ohio :have been by far thecountry's largest industrial emitters of a chemical that eats the Earth's protective ozone layer.

• More than 800,000 pounds of CFC-114 emitted in to atmosphere, in 1999. -- as another example of the hidden costs of nuclear power.

CFC-114: 1,2-dichlorotetrafluoroethane

Types of Radioactive Waste• Very low-level waste (VLLW): Radioactive waste that can be

safely disposed of with ordinary refuse

• Low-level waste (LLW): Trash from routine operations, It does not usually require special handling, unless contaminated with alpha emitters.

• Intermediate (medium) level waste (ILW): Radioactive waste which has little heat output. These wastes usually require remote handling

• High-level waste (HLW): Comprise either spent fuel or the highly active wastes resulting from the first stage of fuel reprocessing. A high degree of isolation from the biosphere, is required

Composition of the Spent Fuel

• The spent nuclear fuel contains about 93% uranium (mostly U-238)

• about 1% plutonium

• less than 1% minor actinides (neptunium, americium, and curium)

• 5% fission products

Global Nuclear Wastes

• Typical reactor will generate 20 to 30 tons of high-level nuclear waste annually

• The global volume of spent fuel is ,290,000 tons , and is

growing by approximately 10,000 tons annually.

• Despite billion of dollars of investment in various disposal options, the nuclear industry and governments have failed to come up with a feasible and sustainable solution.

Radioactivity of plutonium

• Half life of plutonium (Pu-239) is 24000 years

• Life span of at least 240,000 years• Neanderthal Man died out

30,000 years ago

U-238 decay chain (main branch)

• Uranium-238 (half-life: 4.46 billion years) alpha decay ==>

• Thorium-234 (half-life: 24.1 days) beta decay ==>• Protactinium-234m half-life: 1.17 minutes) beta decay ==>• Uranium-234 (half-life: 245,000 years) alpha decay ==>• Thorium-230 (half-life: 75,400 years) alpha decay ==>• Radium-226 (half-life: 1,600 years) alpha decay• ==>• Radon-222 (half-life: 3.82 days) ==> followed by radon

decay products (polonium, bismuth, lead isotopes)

Thorium-232

• Thorium-232 is, like U-238, has its own decay chain

• Dangerous decay products build up relatively quickly in Th-232

• They are thorium-228, actinium-228 (a beta-emitter), radium-228, and radium-224

• Radium-224 gives off radon-220 (which is similar to radon-222)

Repository capacity

• Three isotopes, which are linked through a decay process (Pu241, Am241, and Np237), are the major contributors to the estimated dose for releases from the repository, typically occurring between 100,000 and 1 million years, and also to the long-term heat generation that limits the amount of waste that can be placed in the repository

Nuclear Waste Generation, Pollution and

Remediation at the Hanford Nuclear

Reservation Divan Fard, Jim Amonette,

Elsa Rodriguez, Jose Marquez and Roy Gephart

Hanford Today:Waste and Nuclear Materials

Volume/gal Curies Chemicals

Tank Waste( 179) 54 million 200 million220,000 MT

Solid Waste 190, million 6 million65,000 MT

Soil and 293 billion 1 million 100,000 to 300,000 MT

Groundwater

Facilities 1300 million 10 million ----

Nuclear Material *186,000 200 million ----

*2.5 million times the Nagasaki bomb

Groundwater

Waste tanks, ranging in size from 55000 to 1100000 gallons. Only 13 pounds of plutonium were used to destroy Nagasaki.

Drinking water mortality risks in millionth per Pico curie intake (Ref. value: Pu-239 = 2.85)

• U-238 decay chain (main risks)

• U-238: 1.13• U-234: 1.24• Th-230: 1.67• Ra-226: 7.17

• Th-232 decay chain (main risks)

• Th-232: 1.87• Th-228: 1.82• Ra-228: 20.0• Ra-224: 2.74

Pico:10−12 or 0.000000000001

www.ieer.org/comments/cotter.ppt

http://www.ieer.org/comments/ComplexSPEIS.pdf


Solid Waste

• 196 million gal of low-level and transuranic waste

• 6 million curies (1998)

• 360 kg of plutonium

• 580 MT of uranium

Early Years Later Years

Radio nuclide Releases to the Atmosphere

32M curies released•12M curies from

reactors•20M curies from reprocessing plants

Key Radionuclides Contributing to Dose (curies)

Year I-131 Ru-103/-106 Ce-144 Sr-90Pu-239

1944-1949 697,000 290 1740 30 2

1950-1959 43,000 1130 630 10 <1

1960-1969 460 130 1350 25 <1

1970-1972 <1 1 50 2 <199% of dose from I-

1311% of dose from these radionuclides

History of Hanford Tank Waste530 Million gal

High-Level Waste Generated (1944-1988)

Reprocessed239,000 m3

Disposed to Ground*

490,500 m3

Leaked to Ground 3800 m3

Evaporated 1.05 million

m3

53 million galRemaining in Tanks

(2000)*after radionuclide scavenging or cascading

Started1956

Started1945

Started1956

Started1951

Ponds1944-1990s

Ponds, 1944-1990s

French Drains1944-1980s

French Drains1944-1980s

Reverse Wells, 1945 – 1955, (one to 1980)

Specific Retention Trenches 1944-1973

Cribs, 1944-1990s

Radioactive contaminants include: • iodine-129, strontium-90, technetium-99,

tritium, and uranium. Non-radioactive contaminants, chromium and chlorinated solvents.

Remediation Techniques:• Commonly sought Pump-and-treat method;

Savannah river site• In situ remediation

Contaminants of Hanford Nuclear reservation groundwater:

History of U.S. Nuclear Waste Policy

• 1956: National Academy of Sciences concludes that a deep geologic repository is the best permanent solution for disposal of

high-level nuclear wastes (HLW)

• 1977: Reprocessing of commercial spent nuclear fuel (SNF) is prohibited under President Carter

• 1982: Congress passes Nuclear Waste Policy Act (NWPA)– Made DOE responsible for the permanent disposal of U.S.’s SNF and HLW

– Created Office of Civilian Radioactive Waste Management in DOE

– Set up program to begin investigation of sites as potential geologic repositories and established site recommendation/approval process

– Established Nuclear Waste Fund, and directed DOE to begin accepting commercial spent fuel for disposal in 1998 in exchange for utilities’ payment of fees into the fund

24 years

Why Yucca Mountain?

Yucca mountain Yucca mountain

Repository Reference Design Concept

Repository Concept

N

Waste Handling Building

Waste TreatmentBuilding

TransporterMaintenance

Building

Surface Layout Waste Receiving

North Portal Entrance

Alcove #1

Enhanced Characterization Repository Block

Drift

Subsurface LayoutWaste Emplacement

To accommodate 70,000 metric tons, the proposed repository would include

approximately 36 miles of tunnels which would hold approximately

10,000 waste packages.

Repository Program Schedule

Activity Date

Submited Yucca Mt. License Application to NRC

Feb 19, 2009

Begin Nevada rail construction (Caliente route,”) http://www.rgj.com/article/20090411/NEWS/904110320/1321

Oct. 2009

NRC authorizes repository construction

Sept. 2011

Complete initial rail accessJun. 2014

Complete construction for initial repository operations

Mar. 2016

Begin receipt of Nuclear WastesMar. 2017

http://www.nrc.gov/waste/hlw-disposal/yucca-lic-app.html

http://www.rgj.com/article/20090411/NEWS/904110320/1321

How will Spend Nuclear Wastes and High Level Waste be Transported?

• Per 2004 Record of Decision, DOE will transport SNF and HLW mostly by rail, with additional limited truck and barge shipments

Drinking water mortality risks in millionth per Pico curie intake (Ref. value: Pu-239 = 2.85)

• U-238 decay chain (main risks)

• U-238: 1.13• U-234: 1.24• Th-230: 1.67• Ra-226: 7.17

• Th-232 decay chain (main risks)

• Th-232: 1.87• Th-228: 1.82• Ra-228: 20.0• Ra-224: 2.74

Pico:10−12 or 0.000000000001



April 26, 1986 , Chernobyl disaster

http://en.wikipedia.org/wiki/File:Chernobyl_Disaster.jpg

3.5 million sick,

one/third of them children

Chernobyl

4,000 deaths in 20 years

4056 ( 03/24/11)

http://www.who.int/mediacentre/news/releases/2005/pr38/en/index.html

400 million people exposed in 20 countries

Health effects radiation exposure:

-increased likelihood of cancer

-birth defects including long limbs,

-braindamage

-conjoined stillborn twins

-reduced immunity

-genetic damage

Melt Down, Three-Mile Island PA 1979

http://commons.wikimedia.org/wiki/Image:Three_Mile_Island_%28color%29.jpg

Health around TMI

• In 1979, hundreds of people reported nausea, vomiting, hair loss, and skin rashes. Many pets were reported dead or showed signs of radiation

• Lung cancer, and leukemia rates increased 2 to 10 times in areas within 10 miles downwind

• Farmers received severe monetary losses due to deformities in livestock and crops after the disaster that are still occurring today.

Plants near TMI

-lack of chlorophyll

-deformed leaf patterns

-thick, flat, hollow stems

-missing reproductive parts

-abnormally large leaf sizeTMI dandelion leaf at right

Animals Nearby TMI• Many insects disappeared

for years.

– Bumble bees, carpenter bees, certain type caterpillars, or daddy-long-leg spiders

– Pheasants and hop toads have disappeared.

Other reactor accidents (besides TMI and Chernobyl)

• 1952 Chalk River, Ontario– Partial core meltdown

• 1957 Windscale, England– Graphite reactor fire contaminates 200 square miles.

• 1975 Browns Ferry, Alabama– Plant caught fire

• 1976 Lubmin, East Germany– Near meltdown of reactor core .

• 1999 Tokaimura, Japan– Nuclear fuel plant spewed high levels of radioactive gas

– March 11, 2011 Fukushima Daiichi Nuclear Accident

Sustainable Energy Alternatives

• Bioenergy: biomass, such as plant matter and animal waste, can yield power, heat, steam, and fuel.

• Geothermal: renewable heat energy can be harnessed from deep within the earth.

• Wind: turbines turning in the air convert kinetic energy in the wind into electricity.

• Solar: the sun’s energy can be captured and used to produce heat and electricity.

http://www.eia.doe.gov/kids/energyfacts/sources/renewable/geothermal.html#WhatIs

• Hydrogen: if produced by renewable sources, it can power fuel cells to convert chemical energy directly into electricity, with useful heat and water as the only byproducts.

• Tidal: using the movement of the ocean to power turbines and generate electricity.

End


What incorrect assumption did Becquerel make in beginning his investigation of uranium, sunlight, and photographic paper? What correct conclusion did he reach when he found spots on paper that was in contact with uranium exposed to the sun? What incorrect conclusion did he reach when he made this observation? What result caused him to turn the entire project over to Marie Sklodowska Curie for further investigation?

QUESTION


Which component of radioactivity would be stopped by this single page? Which two components would be stopped (completely or almost completely) by this entire book? Which component would pass, almost undiminished, through both this single page and this entire book?

QUESTION


How does an atom’s atomic number change when its nucleus loses a(n): (a) α particle, (b) β particle, (c) ray? How does that atom’s mass number change with the loss of each of these?

QUESTION


In what ways does the structure of an atom of antihydrogen differ from the structure of an atom of hydrogen? In what ways are the two atoms similar?

QUESTION


When an atom of uranium –235 is bombarded with neutrons, one of the many fission reactions it can undergo produces barium and an additional element (as well as energy and additional neutrons) but no α particles or β particles. With this in mind, and with reference to the periodic table, name the additional element produced in this particular mode of fission.

QUESTION


(a) What is the advantage to using U-235 rather than U-238 as the fissionable material in building a fission bomb? (b) What is the disadvantage to using U-235 rather than U-238 as the fissionable material?

QUESTION


How was a critical mass achieved in the detonation of the U-235 bomb? In the detonation of the Pu-239 bomb?

QUESTION


Using the Law of Conservation of Mass and the Law of Conservation of Energy, show why nuclear fission might not be viewed as a chemical reaction.

QUESTION


Calculate the mass defect of an atom of Pu-239. The measured mass of an atom of Pu-239 is 239.05 amu.

QUESTION


Table 4.2 shows that the efficient burning of 1g of gasoline could keep a 100-watt light bulb burning for 8 minutes. How long would the energy obtained by the complete conversion of the gram of gasoline directly into energy keep the bulb lit?

QUESTION

Documents

Chapter 4: Discovering the Secrets of the Nucleus From a Photographic Mystery to the Atomic Bomb © 2003 John Wiley and Sons Publishers Courtesy Fermilab/Peter