Chemistry
Unit 3: Atomic Structure
Basics of the Atom
Subatomic
Charge
Particle
Location in
the Atom
Mass
proton
1+
in nucleus
~ 1 a.m.u.
neutron
0
in nucleus
~ 1 a.m.u.
electron
1–
around nucleus ~ 0 a.m.u.
a.m.u.: unit used to measure mass of atoms
“atomic mass unit”
1 amu = 1.66 x 10-24 g
atomic number: # of p+
-- the whole number
on Periodic Table
-- determines identity
of the atom
10
Ne
20.1797
mass number: (# of p+) + (# of n0)
(It is NOT on “the Table.”)
To find net charge on an atom, consider
e–
p+ and ____.
____
ion: a charged atom
anion: a (–) ion
cation: a (+) ion
-- more e– than p+
-- more p+ than e–
-- formed when
atoms gain e–
-- formed when
atoms lose e–
I think that an ions are negative ions.
“When I see a cation, I see a positive ion;
that is, I… C A + ion.”
Humor
Two atoms are walking down the street.
One atom says to the other, “Hey! I think I lost an electron!”
The other says, “Are you sure??”
“Yes, I’m positive!”
A neutron walks into a restaurant and orders a couple
of drinks. As she is about to leave, she asks the waiter
how much she owes. The waiter replies, “For you,
No Charge!!!”
Don’t trust atoms…they make up everything.
Other Mnemonic Devices
Metals form positive
ions
Cations are “paws”itive
Description
Net
Charge
Atomic
Number
Mass
Number
15 p+
16 n0
18 e–
3–
15
31
P3–
38 p+
50 n0
36 e–
2+
38
88
Sr2+
2–
52
128
Te2–
1+
19
39
K+
52 p+
76 n0
54 e–
19 p+
20 n0
18 e–
Ion
Symbol
Isotopes: different varieties of an element’s atoms
-- have diff. #’s of n0; thus, diff. mass #’s
-- some are radioactive; others aren’t
All atoms of an element react the same chemically.
p+
n0
Common Name
H–1
Mass
1
1
0
protium
H–2
2
1
1
deuterium
H–3
3
1
2
tritium
Isotope
C–12 atoms
6 p+ 6 n0
C–14 atoms
6 p+ 8 n0
stable
radioactive
Complete Atomic Designation
…gives very precise info about an atomic particle
mass #
charge (if any)
element
symbol
atomic #
125
53
Goiter due to
lack of iodine
I
–
iodine is now
added to salt
Protons
Neutrons
Electrons
92
146
92
11
12
10
34
45
36
27
32
24
17
20
18
25
30
18
Complete
Atomic
Designation
238
U
92
23
+
Na
11
79
2–
Se
34
59
3+
Co
27
37
–
Cl
17
55
7+
Mn
25
Average Atomic Mass (AAM)
This is the weighted average mass of all atoms of
an element, measured in a.m.u.
Ti has five naturallyoccurring isotopes
For an element with
isotopes A, B, etc.:
AAM = Mass A (% A) + Mass B (% B) + …
% abundance
(use the decimal form of the %
e.g., use 0.253 for 25.3%)
Lithium has two isotopes.
Li-6 atoms have mass 6.015 amu;
Li-7 atoms have mass 7.016 amu.
Li-6 makes up 7.5% of all Li atoms.
Find AAM of Li.
Li batteries
AAM = Mass A (% A) + Mass B (% B)
AAM = 6.015 amu (0.075) + 7.016 amu (0.925)
AAM =
0.451 amu
+
6.490 amu
AAM = 6.94 amu
** Decimal number on Table refers to…
molar mass (in g) OR AAM (in amu).
6.02 x 1023 atoms
1 “average” atom
Isotope
Mass
Si-28
Si-29
27.98 amu
28.98 amu
?
Si-30
%
abundance
92.23%
4.67%
3.10%
AAM = MA (% A) + MB (% B) + MC (% C)
28.086 = 27.98 (0.9223) + 28.98 (0.0467) + X (0.031)
28.086 =
28.086 =
0.92663 =
0.031
25.8060
+
1.35337
27.15937
X = MSi-30 = 29.89 amu
+ 0.031X
+ 0.031X
0.031X
0.031
Historical Development of the Atomic Model
Greeks (~400 B.C.E.)
Democritus & Leucippus
Matter is discontinuous (i.e., “grainy”).
“atomos” = uncuttable or indivisible
Greek model
of atom
Solid and INDESTRUCTABLE
Hints at the Scientific Atom
** Antoine Lavoisier:
law of conservation of mass
mass R = mass P
** Joseph Proust (1799):
law of definite proportions: every
compound has a fixed proportion
e.g., water…………………….. 8 g O : 1 g H
chromium (II) oxide……. 13 g Cr : 4 g O
Hints at the Scientific Atom (cont.)
** John Dalton (1803):
law of multiple proportions:
When two different compounds
have same two elements, equal
mass of one element results in
integer multiple of mass of other
2
e.g., water…………………….. 8 g O : 1 g H
hydrogen peroxide..…….16 g O : 1 g H
3
chromium (II) oxide……. 13 g Cr : 4 g O
chromium (VI) oxide……13 g Cr : 12 g O
John Dalton’s Atomic Theory (1808)
1. Elements are made of
indivisible particles called atoms.
2. Atoms of the same element are exactly
alike; in particular, they have the same mass.
3. Compounds are formed by
the joining of atoms of two
or more elements in fixed,
whole number ratios.
e.g., 1:1, 2:1, 1:3, 2:3, 1:2:1
NaCl, H2O, NH3, Fe2O3, C6H12O6
Dalton’s
model
of atom
** William Crookes
(1870s):
Rays causing
shadow were
emitted from
cathode.
Maltese cross CRT
radar screen
television
computer
monitor
J.J Thomson (~1900)
J.J. Thomson discovered
that “cathode rays” are…
…deflected by electric
and magnetic fields
electric field lines
“cathode rays”
Crooke’s tube
… (–) particles
J.J. Thomson
++++++
– – – – – –
electrons
phosphorescent
screen
William Thomson (a.k.a., Lord Kelvin):
Since atom was known to be
electrically neutral, he proposed
the plum pudding model.
-- Equal quantities of (+) and (–)
charge distributed uniformly
in atom.
Lord Kelvin
++ ++
+ ++ +
+ ++
–
–
–
–
–
-- (+) is ~2000X more massive
than (–)
plum
pudding
–
–
–
–
–
–
Thomson’s plum
pudding model
Ernest Rutherford (1909)
Gold Leaf Experiment
Beam of a-particles (+) directed
at gold leaf surrounded by
phosphorescent (ZnS) screen.
a-source
lead
block
particle
beam
ZnS
screen
gold
leaf
Most a-particles passed through, some angled
slightly, and a tiny fraction bounced back.
Conclusions:
1. Atoms are mostly empty space
2. (+) particles are concentrated at center
nucleus = “little nut”
3. (–) particles orbit nucleus
Rutherford’s
ModelModel
Dalton’s
(also
thePudding
Greek)
Thomson’s
Plum
Model
–
+
– +
+
–
– +
–
–
+
+
+
N
–
+
–
–
–
–
–
–
+– + + –
–
–
** James Chadwick
discovered neutrons in 1932
n0 have no charge
and are hard to detect
purpose of n0 = stability of nucleus
photo from liquid
H2 bubble chamber
Chadwick
And now we know of many
other subatomic particles:
quarks,
muons,
positrons,
neutrinos,
pions, etc.
Honors
Chemistry
Nuclear
Chemistry
Chemical reactions involve changes with electrons.
________________
Nuclear reactions involve changes in atomic nuclei.
________________
radiation and
Spontaneously-changing nuclei emit ________
radioactive
are said to be _________.
energy and/or particles
Unstable Isotopes
and
+
or
Excited
nucleus
Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 439
More stable
nucleus
Energy
Particles
Radiation
Radioactivity
nucleons: protons (p+) and neutrons (n0)
mass number: (p+ + n0) in a given atom
isotopes: species having the same number
of p+, but different numbers of n0
radioisotopes
-- radioactive ones are called ___________
nuclide: a nucleus w/a specified
number of p+ and n0
radionuclides
-- radioactive ones are called ___________
atomic number: (Z); # of
p+
these are unstable
and emit radiation
Typical Radiation Exposure
Values per person per Year in the United States
Source
Radiation
Source
Radiation
atmosphere at sea level*
26 mrem
dental X-ray
1 mrem
ground
30 mrem
chest X-ray
6 mrem
foods
20 mrem
X-ray of hip
65 mrem
air travel above 1,800 m
4 mrem
CAT scan
110 mrem
construction site
7 mrem
nuclear power plant nearby
0.02 mrem
X-ray of arm or leg
1 mrem
TV and computer use
2 mrem
*Add 3 mrem for every 300 m of elevation
Packard, Jacobs, Marshall, Chemistry Pearson AGS Globe, page 341
Effects of Instantaneous Whole-Body
Radiation Doses on People
Remember, most of you had <350
mrems in a year!
Dose (rems)
Effect
Alexander Litvinenko
>1000
Death within 24 h from destruction of the neurological
system.
750
Death within 4 - 30 d from gastrointestinal bleeding.
150 – 750
Intensive hospital care required for survival. At the
higher end of range, death through infection resulting
from destruction of white-blood cell-forming organs
usually takes place 4 – 8 weeks after accident.
Those surviving this period usually recover.
< 50
Only proven effect is decrease in white blood cell count.
Alexander
Litvinenko
• Former KGB/FSB (Federal Security Service)
agent
• Publicly criticized government and alleged gov’t
involvement in assassination of a journalist and a
Russian oil tycoon, among other conspiracy
theories
• Met with KGB agents, mysteriously poisoned with
210Po (t
1/2 = 138.4 d), a radionuclide
• Dead within 23 days (Nov. 2006)
Radioactive Decay
For nuclear equations, mass (top) and charge (bottom)
must balance.
alpha (a) decay:
234
92 U
230
4
90 Th + 2 He
(go DOWN
two #s on Table)
a-particle (i.e., a He nucleus):
massive, slow-moving;
stopped by skin, paper
Alpha Decay in Smoke Detector
Np-237
Am-241
The alpha decay of
241Am
Alpha
Particle
(americium-241) to form 237Np (neptunium-237)
Measuring Circuit in
Detection Chamber
Contact
Terminal
screw
Reference
chamber
Radioactive
source
Clean air
High
current
value
1
2
0
-
Current
+
+
+
- - +
- +-
Ionized
particles
Radioactive
material
Smoke
Control
unit or
processor
Plastic
cover
Alarm
indicator
Low
current
value
Detection
chamber
2
-
+
Detection
chamber cover
1
0
Smoke
attached
to particles
Radioactive
material
+
+
- - +
- +-
234
91 Pa
beta (b) decay:
234
0
92 U + –1 e
(go UP
one # on Table)
b-particle (i.e., a fast-moving
electron): little mass; stops
~1 cm into body
In b-decay, the effect is that a n0 is converted
into a p+, ejecting an e– from the nucleus.
1
0n
0
1
–1 e + 1 p
NOTE: There are no e– in the nucleus. The ejected e–
is formed when energy released from the
E = mc2
nucleus “congeals” into mass, via _______.
gamma radiation: consists of high-energy photons
-- can penetrate to internal organs
-- gamma ray: 0 g (or just g)
0
emitted when nucleons
rearrange into a more
stable configuration
Hulk transformations
Scrubs Hulk
-- gamma radiation often accompanies
other nuclear decays
234
92 U
230
4
0
90 Th + 2 He + 2 0 g
Radioactive Skittles
Radiation
You have 3 radioactive skittles in front of you:
Red: α rad.
Purple: β rad.
Green: g rad.
One must be eaten, one must stay in your hand, and the
last one must be put in your pocket…
What arrangement will cause you the
least harm?
positron decay: 23 Mg
12
23
0
0
11 Na + 1 e + 0 n
positron: identical to an e–, but (+)
neutrino: “massless,” chargeless particle
electron capture: nucleus captures orbiting e–
11
0
6 C + –1 e
11
0
5B + 0n
The effect of positron decay and electron capture
is to turn a p+ into a n0.
1
1p
0
1
1e + 0n
POSITRON DECAY
1
0
1 p + –1 e
1
0n
ELECTRON CAPTURE
Recap: Types of Radiation
Alpha
Composition
Helium nucleus
Symbol
Charge
Mass
Approx. Energy
Penetrating
Power
a,
4
2
He
2+
~ 4 amu
*5 MeV
Low
Beta
Electron
b,
Gamma
High energy wave + charged e-
0
-1 e
11/1837 amu
*0.5 – 1 MeV
Moderate
Positron
0
0
g
No charge
No mass
b,
0
1e
1+
1/1837 amu
*1 MeV
*0.5 – 1 MeV
Very High
Moderate
*1 MeV =
1.602 x 10-13 J
Nuclear Transmutations
These are induced by a bombarding particle,
and are typically written in the following order:
27
13 Al
+
target
nucleus
4
2 He
30
15 P
bombarding
particle
product
nucleus
This reaction is abbreviated…
27
30
13 Al (a, n) 15 P
Ernest Rutherford was
the first to artificially
transmute elements.
+
1
0n
ejected
particle
Write the shorthand for
27
1
Al
+
13
0n
24
4
Na
+
11
2 He
27
24
Al
(n,
a)
13
11 Na
Write the equation for
14
17
7 N (a, p) 8 O
14
4
7 N + 2 He
17
1
8O + 1 H
14
4
7N + 2a
17
1
8O + 1 p
Nuclear Stability
strong force
Nucleons are held together by the __________.
~1.5 n0 : 1 p+
Band (or Belt)
of Stability
# of n0
~1 n0 : 1 p+
0
Z (i.e., # of p+) 83 At Z > 83, none are stable
(i.e., all are radioactive).
In general, the farther
away an isotope is from
the “band,” the more
unstable and radioactive it
is and the shorter its halflife.
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.
Nuclei that…
…have too many…
…and stabilize by…
…are above belt…
n0
…are below belt…
p+
b-emission
positron emission
(or e– capture)
…have Z > 83…
p+ and n0
a-emission
Examples:
(a)
242
94 Pu
4
238
2 a + 92 U
(b)
163
64 Gd
0
163
–1 b + 65 Tb
145
65 Tb
0
145
1 e + 64 Gd
(positron emission
or e– capture)
145
0
65 Tb + –1 e
145
64 Gd
Number of neutrons
Effects of Radioactive Emissions
on Proton and Neutrons
Loss of 4 He
2
Loss of 0 e
-1
Loss of 0 e or
1
electron capture
Number of protons
A radioactive series is the decay sequence a
radionuclide goes through to become stable.
a
b
e.g., U-238
Th-234
Pa-234 , etc.
-- there are three basic series, ending with…
Pb-206, Pb-207, and Pb-208.
Radioactive materials will continue to decay until they
reach a stable material
(Usually with an atomic number less than 83.)
Stable Isotope
Rates of Radioactive Decay
Each radioisotope has a unique rate of decay,
its half-life, t1/2, which is the time required for
half of a sample of a radioisotope to decay into
something more stable. An isotope’s half-life is:
(1) independent of T, P, and its state of
chemical combination
(2) useful in radioactive dating
“Otzi” the Iceman lived circa 3300 B.C.,
according to radiocarbon dating analyses.
Say that a 120 g
sample of C-14 is
found today…
Years
from now
0
5,730
11,460
17,190
22,920
14
6
C
= C–14
= N–14
g of C–14 g of N–14
present
present
120
0
60
30
60
90
15
7.5
105
14
7
112.5
N
+
0
-1
e
Molybdenum-99 has a half-life of 2.79 days.
How much of a 16.80 mg sample of Mo-99 is
left after 8.37 days?
start 16.80 mg
after one t1/2 8.40 mg
8.37 days
= 3 half-lives
after two t1/2
4.20 mg
2.79 days
after three t1/2
2.10 mg
(this is the amount of
radioactive Mo-99 left;
i.e., 14.70 mg is
now stable mat’l)
½  ½  ½  etc.
Example: Carbon-14 emits beta radiation and decays with a
half-life of 5730y. Assume you start with a mass of 2.00g of
carbon-14.
a. How long is 3 half-lives?
b. How many grams will remain at the end of 3 half
lives?
c. How many years will it take for only 0.0625g to
remain?
a. t1/2 = 5730 y, 3(5730 y) = 17190 y
1
b. 2.00 g
c. 2.00 g
5
1.00 g
1.00 g
4
2
0.50 g
0.50 g
3
3
0.25 g
t1/2 = 5730 y, 5(5730 y) = 28650 y
0.25 g
2
0.125 g
1
0.0625 g
t½ equation
2.00g
1
1.00g
2
0.50g
3
0.25g
2.00g(1/2)(1/2)(1/2) or 2.00(1/2)3 = 0.25 g
N0 = initial amount
N0(1/2)n = N
N = final amount
n = # of half lives
If 150.0 g of a radioactive substance undergoes 25 half
lives, how many g will remain?
150.0 g (1/2)25 = 4.47 x 10 -6 g
Half Life Graph (Sr-90 Activity)
Half Life Sr-90
35
Mass (g) Sr-90
30
25
20
Ряд1
15
10
5
0
2000
2050
2100
Year
2150
2200
Energy Changes in Nuclear Reactions
Energy and mass are
two sides of the same coin.
E = mc2
c = 3.00 x 108 m/s
m = mass , in kg
E = energy, in J
When a system loses/gains energy, it loses/gains mass.
In chemical reactions, this mass change is nearly
undetectable, so we speak of mass as being
“conserved,” when it really isn’t. The amount of
“mass-and-energy-together,” however, IS conserved.
Mass changes in nuclear reactions are much larger
than in chemical reactions.
Nuclear Binding Energy
mass of
nucleus
<
mass of individual
nucleons in nucleus
rest masses: n0 = 1.00866 amu = 1.67493 x 10–24 g
p+ = 1.00728 amu = 1.67262 x 10–24 g
mass of
mass of
mass defect = constituent – nucleus
nucleons
(or “mass deficiency”)
“Tighter,
lighter."
“Separate,
heavier."
This “missing” mass is converted
into energy, which is used to
hold the nucleus together.
Use mass defect, E = mc2, and # of nucleons to
calculate binding energy per nucleon (BE/n).
-- large BE/n means great nuclear stability
-- BE/n is largest for Fe-56, meaning that
nuclei __________ than Fe-56…
(1) LARGER…decay OR can undergo fission
+ ENERGY
(2) SMALLER…can undergo fusion
+
ENERGY
Both fission and fusion are exothermic.
Calculate the binding energy per nucleon of N-14,
which has a nuclear mass of 13.999234 amu.
7 p+ (1.00728 amu) = 7.05096 amu
7 n0 (1.00866 amu) = 7.06062 amu
14.11158 amu
m.d. = 14.11158 – 13.999234 = 0.11235 amu
0.11235
amu
1g

  1 kg 
 = 1.8656 x 10–28 kg


23
 6.02 x 10 amu   1000 g 
BE mc 2 1.8656 x 1028 (3 x 108 )2


n
n
14
= 1.20 x 10–12 J/nucleon
Most BE’s are
measured in
electron-volts…
1 eV = 1.60 x 10–19 J
This is 7.50 x 106 eV, or 7.50 MeV.
Nuclear Fission
Fission requires… slow-moving neutrons.
distance too big;
strong force weakens;
+/+ repulsion takes over
slow
fast nn00
released n0;
free to split
more nuclei
Important fissionable nuclei: U-233, U-235, Pu-239
chain reaction: one nuclear reaction leads
to one or more others
1
0
n
Nuclear Fission Example
Anywhere
from 1-9 n0
are released!
Chain Reaction
critical mass: the mass of fissionable material required
to maintain a chain reaction at a constant rate
supercritical mass: the mass above which the chain
reaction accelerates
safe
safe
critical
mass
supercritical
mass
(reaction
maintained
at constant
rate)
(“Ah jes’ felt lahk runnING.”)
Little Boy, later
dropped
onrun!”)
Hiroshima
(“Run,
Forrest,
Nuclear Power Plants
map: Nuclear Energy Institute
Main benefits:
n0
+ U-238
(1) no air pollution; does NOT
contribute to global warming
(2) small volume of material
consumed
(3) breeder reactors: reactors that
generate new fissionable mat’l
at a greater rate than the
original fuel is consumed
-- non-fissionable U-238
is transmuted into
fissionable Pu-239
U-239
b
Np-239
b
Pu-239
Main problem: What to do with waste?
Schematic of a Nuclear Power Plant
EIW = Emergency Injection Water
PORV = Pressure Release Valve
Shaft
Surface
deposits
Nuclear Waste
Disposal
Aquifier
River
Interbed
rock layer
Host rock
formation
Repository
Waste
package
Interbed
rock layer
Aquifier
Bedrock
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 626
Waste
form
Nuclear Fusion
When small nuclei collide and “fuse” together to form
one nucleus. This results in a LARGE amount of
energy
These reactions occur naturally in stars and are
responsible for the formation of new elements.
Nuclear Fusion
• also called thermonuclear reactions
• products are generally NOT radioactive
• requires high temperatures
(> 40,000,000 K) !!!!
• requires more energy than it produces (right now…)
The tokamak uses
magnetic fields to
contain and heat
the plasma
reactants
Commercial use
still 40+ years away
Nuclear War
• Which countries have nukes and how many?
•
•
•
•
•
•
•
•
•
U.S.A (1945): 7,700
Russia (1949): 8,500
U.K. (1952): 225
France (1960): 300
China (1964): 250
*India (1974): ~100
Israel (~1979): 60-200
*Pakistan (1998): ~110
*North Korea (2006): <10
The End of the World
All countries have signed/agreed to the Nuclear NonProliferation Treaty (1970), except those with a *
As of Dec 2012
Radon
-- an a-emitter from the decay of
radium in rocks and soil
-- very dense; seeps into basements
and is readily inhaled
Ra-226
a
t1/2 = 3.8 d
Rn-222
a
t1/2 = 3.10 min
Po-218
a
Pb-214
radon
formed
-- estimated to be responsible for ____
10% of U.S. lung
cancer deaths
b
Top 10 Myths about
Nuclear Energy
73
Myth # 1:
Americans get most of their yearly
radiation dose from nuclear power plants.
74
Truth:
• We are surrounded by naturally
occurring radiation.
• Less than 1 / 1000th of the average
American’s yearly radiation dose
comes from nuclear power.
• This yearly radiation dose is 100 times
less than we get from coal,[1] 200 times
less than a cross-country flight, and
about the same as eating 1 banana
per year.[2]
1.
2.
National Council on Rad Protection and Measurements No. 92 and 95
CDR Handbook on Radiation Measurement and Protection
75
Sources of Radiation
Rocks, Soil &
Radon – 37%
Medical – 51%
76
Myth # 2:
A nuclear reactor can explode like a
nuclear bomb.
77
Truth:
• It is physically impossible for a reactor to explode like a
nuclear weapon.
• Nuclear weapons contain very special materials in very
particular configurations, none of which are present in a
nuclear reactor.
78
Myth #3:
Nuclear energy is bad for the environment.
79
Truth:
• Nuclear reactors emit no
greenhouse gasses during
operation.
• Over their full lifetimes,
nuclear reactors result in
comparable emissions to
renewable forms of energy
such as wind and solar.[1]
1.
www.nei.org
P.J. Meier, “ Life-Cycle Assessment of Electricity Generation
Systems and Applications for Climate Change Policy Analysis,”
2002
80
Other environmental advantages:
• Nuclear energy requires
less land use than most
other forms of green
energy.
• Nuclear energy does not
deplete useful resources
o There is no other
commercial use for
Uranium
Graphic: Nuclear Energy Institute
81
Myth # 4:
Nuclear energy is not safe.
82
Truth:
• Nuclear energy is as safe – or
safer – than any other form of
energy available.
• No member of the public has ever
been injured or killed in the entire
50-year history of commercial
nuclear power in the U.S.[1]
• In fact, recent studies have shown
that it is safer to work in a nuclear
power plant than an office.[2]
1. Senator Lamar Alexander, as verified by PolitiFact. (2009 Pullitzer Prize Winner)
2.
Nuclear Energy Institute (www.nei.org)
83
Myth # 5:
There is no solution for huge amounts of
nuclear waste being generated.
84
Truth:
• If all the used fuel produced by U.S. nuclear power plants
in nearly 50 years were stacked end to end, it would cover
a football field to a depth of less than 10 yards.[1]
• 96% of this “waste” can be recycled.[2]
• Used fuel is currently being safely stored.
• The U.S. National Academy of Sciences and the
equivalent scientific advisory panels in every major
country support geological disposal of such wastes as the
preferred safe method for their ultimate disposal.[3]
1.
2.
3.
Nuclear Energy Institute: http://nei.org/keyissues/nuclearwastedisposal/storageofusednuclearfuel/
K.S. Krane, Introductory Nuclear Physics, John Wiley and Sons, 1988
Progress Towards Geologic Disposal of Radioactive Waste: Where do We Stand? Nuclear Energy Agency,
OECD report, 1999 (http://www.nea.fr/rwm/reports/1999/progress.pdf)
85
Connecticut Yankee
(decommissioned)
• This is all of the fuel used during the 30 years that this reactor
operated (now being stored in shielded and air cooled casks).
• The waste volume could be reduced even more by
reprocessing.
86
Myth # 6:
Most Americans don’t support nuclear power.
87
Truth:
• In surveys conducted in 2009, it was found that
70% of Americans favor nuclear power.[1]
• 80% of Americans see nuclear energy as an
important source of electricity for the future, and
68% would accept a new reactor at the nearest
nuclear power plant site.[2]
1.
2.
Perspectives on Public Opinion, Bisconti Research, June 2009
Bisconti Research Inc. , April 2009
88
Public Support for
Nuclear Energy
80%
Important
for
Future
Bisconti Research Inc., April 2009
82%
Renew
Licenses
70%
Favor
Nuclear
Energy
59%
Definitely
Build New
Reactors
68%
New Reactor
Acceptable
at
Nearest
Site
89
Most U.S. Nuclear Power Plant Neighbors
Support Nuclear Energy
92%
84%
93%
79%
76%
Important
for
Future
Favor
Nuclear
Renew
licenses
Definitely
Build New
Reactors
New Reactor
Acceptable
At Plant
Source: Bisconti Research Inc.
July 2009 poll of 1,152 U.S. nuclear power plant neighbors; margin of error is +/- 3%
Bisconti Research, Inc., July 2009 poll of 1,152 U.S. nuclear power plant neighbors
90
Myth # 7:
An American “Chernobyl” would kill
thousands of people.
91
Truth:
A Chernobyl-type accident cannot happen
in the United States
• This type of reactor was not built in the United States.
• Western reactors have containment structures to prevent
release of radioactivity to the environment. This worked
as designed for Three Mile Island.
• Western reactors are stable under all possible reactor
conditions, so a runaway reaction like the one at
Chernobyl is impossible.
92
Myth # 8:
Nuclear waste cannot be safely
transported.
93
Truth:
• Radioactive materials have been shipped in this country
for more than 60 years.
• 3 million packages of radioactive materials are shipped
each year in the U.S.
• As when transporting other commodities, vehicles
carrying radioactive materials have been involved in
transportation accidents. However, NO deaths or
serious injuries have resulted from exposure to the
radioactive contents of these shipments.[1]
1.
U.S. Department of Energy, Transporting Radioactive Materials: Answers to Your Questions, June 1999
94
Sandia Crash Tests
Casks for
transporting nuclear
waste are tested to
survive various types
of crashes and
exposure to fire. All
tests show that they
survive intact without
release of
radioactivity.
Impact with a locomotive at 80mph
95
Myth # 9:
Used nuclear fuel is deadly for
10,000 years.
96
Truth:
•
Used nuclear fuel can be recycled to make new fuel
and other useful products.[1]
•
Most of the waste from this process will require a
storage time of less than 300 years.
1.
K.S. Krane, Introductory Nuclear Physics, John Wiley and Sons, 1988
97
Radioactivity Vs. Time
98
Source: Dr. Mick Apted, Monitor Scientific (2009)
Myth # 10:
Nuclear energy can’t reduce our
dependence on foreign oil.
99
Truth:
Nuclear-generated
electricity powers
o electric trains
o subway cars
o automobiles
100
Truth:
• Near-term
o nuclear power can provide electricity for
expanded mass-transit and plug-in hybrid
cars.
o Small modular reactors can provide
power to islands (e.g. HI, PR, Nantucket
and Guam) currently burning oil to
generate electricity.[1]
• Longer-term
o Nuclear power can reduce dependence
on foreign oil by producing hydrogen for
fuel cells and synthetic liquid fuels.
Photo: Hydrogencarsnow.com
101
1.
U.S. Energy Information Administration