The mission of the Organiza1on for Economic Co-‐opera1on
and Development (OECD) is to promote policies that will
improve the economic and social well-‐being of people around
Assignment for Tuesday Oct. 2, 2012!
AUSTRALIA 7 June 1971
AUSTRIA 29 September 1961
BELGIUM 13 September 1961
CANADA 10 April 1961
CHILE 7 May 2010
CZECH REPUBLIC 21 December 1995
DENMARK 30 May 1961
ESTONIA 9 December 2010
FINLAND 28 January 1969
FRANCE 7 August 1961
GERMANY 27 September 1961
GREECE 27 September 1961
HUNGARY 7 May 1996
ICELAND 5 June 1961
IRELAND 17 August 1961
ISRAEL 7 September 2010
ITALY 29 March 1962
JAPAN 28 April 1964
KOREA 12 December 1996
LUXEMBOURG 7 December 1961
MEXICO 18 May 1994
NETHERLANDS 13 November 1961
NEW ZEALAND 29 May 1973
NORWAY 4 July 1961
POLAND 22 November 1996
PORTUGAL 4 August 1961
SLOVAK REPUBLIC 14 December 2000
SLOVENIA 21 July 2010
SPAIN 3 August 1961
SWEDEN 28 September 1961
SWITZERLAND 28 September 1961
TURKEY 2 August 1961
UNITED KINGDOM 2 May 1961
UNITED STATES 12 April 1961
What about Elements?
elements as fundamental substances that
cannot be broken down further by chemical
Atomic Number ?
Atomic Weight ?
The Chart of Nuclides
Atomic Number ? Z or the number of protons
Atomic Weight ? Z+ N= A + number of protons + number of neutrons
Signatures of Nucleosynthesis
B 2 FH
Nuclei are made in Stars
Iron, Cobalt, Copper, Zinc,Iodine
Explosion of a star that died 13 Billion years ago
Ar1st: Nicolle Roger Fuller (NSF)
Each heavy atom in our body
was processed through ~40
supernova explosions since the
beginning of time!
We are made of star stuff….
Where is the Energy coming from??????
Splitting the Uranium Atom:
Uranium is the principle element used in nuclear reactors
and in certain types of atomic bombs. The specific isotope
used is 235 U. When a stray neutron strikes a 235 U nucleus,
it is at first absorbed into it. This creates 236 U. 236 U is
unstable and this causes the atom to fission.
• 235 U + 1 neutron
• 235 U + 1 neutron
2 neutrons + 92 Kr + 142 Ba + ENERGY
2 neutrons + 92 Sr + 140 Xe + ENERGY
Binding Energy Curve:
Energy can be released from fusion and fission!
Nuclear binding energy = Δmc 2
For the alpha particle Δm= 0.0304 u which gives a binding
energy of 28.3 MeV.
The enormity of the nuclear binding energy can perhaps be better
appreciated by comparing it to the binding energy of an electron in an atom.
The comparison of the alpha particle binding energy with the binding energy
of the electron in a hydrogen atom is shown below. The nuclear binding
energies are on the order of a million times greater than the electron
binding energies of atoms.
Americium -‐241: Used in many smoke detectors for homes and business...
Cadmium -‐109: Used to analyze metal alloys for checking stock, sor1ng scrap.
Calcium -‐ 47: Important aid to biomedical researchers studying the cell func1on and
bone forma1on of mammals.
Californium -‐ 252: Used to inspect airline luggage for hidden explosives...to gauge the
moisture content of soil in the road construc1on and building industries...and to measure
the moisture of materials stored in silos.
Carbon -‐ 14: Helps in research to ensure that poten1al new drugs are metabolized without
forming harmful by-‐products.
Cesium -‐ 137: Used to treat cancers...
Chromium -‐ 51: Used in research in red blood cell survival studies.
Cobalt -‐ 57: Used in nuclear medicine to help physicians interpret diagnosis scans of
pa1ents' organs, and to diagnose pernicious anemia.
Cobalt -‐ 60 : Used to sterilize surgical instruments...spices/fruits
Copper -‐ 67: cancer
very long- longer than age of earth….billions of yrs
C 5730 yrs
Half-lives are very often used to describe quantities undergoing
exponential decay—for example radioactive decay—where the half-life is
constant over the whole life of the decay.
/ 1 100
/ 2 50
/ 4 25
/ 8 12 .5
/ 16 6 .25
/ 32 3 .125
/ 64 1 .563
/ 128 0 .781
... ... ...
n 1/2 n 100(1/2 n )
A quantity is said to be subject to exponential decay
if it decreases at a rate proportional to its value. Symbolically,
this can be expressed as the following differential equation,
where N is the quantity and λ is a positive number called the
The solution to this equation is:
Here N(t) is the quantity at time t, and N 0
= N(0) is the initial
quantity, i.e. the quantity at time t = 0.
Half-‐life:1me required for the decaying quan1ty to fall to one half of its ini1al
This 1me is called the half-‐life, and ojen denoted by the symbol t 1 / 2
The half-‐life can be wriken in terms of the decay constant, or the mean life1me,
Example: 14 C…..0.693/5730 yrs =1.21 x10 -‐4 /yr
or λ=ln2/t 1/2
Example: How old is an object whose 14C content is 10% of what it is in living
Environmental and safety aspects of nuclear energy
Not in My Back Yucca
What are our alternatives for storing
By Brendan I. Koerner
Posted Tuesday, April 15, 2008, at 8:11 AM ET
Environmental Statement on Nuclear
Energy and Global Warming
Too expensive – power plants…
Too dangerous-‐ terrorist groups
Too pollu1ng-‐ radioac1ve waste
Thorium: Is It the Better Nuclear Fuel?
What is special about thorium?
(1) Weapons-grade fissionable material (uranium 233 ) is harder to retrieve safely
and clandestinely from the thorium reactor than plutonium is from the uranium
(2) Thorium produces 10 to 10,000 times less long-lived radioactive waste than
uranium or plutonium reactors.
(3) Thorium comes out of the ground as a 100% pure, usable isotope, which does
not require enrichment, whereas natural uranium contains only 0.7% fissionable
(4) Because thorium does not sustain chain reaction, fission stops by default if
we stop priming it, and a runaway chain reaction accident is improbable.
Here is the thorium sequence in the Rubbia reactor: A neutron is captured by
90 Th232 , which makes it 90 Th 233 .
90 Th232 + 0 n1 -> 90 Th233 
Thorium-233 spontaneously emits a beta particle (an electron from the nucleus, see
p 173), leaving behind one additional proton, and one fewer neutron. ("...Nuclear
Energy" p134) This is called "beta decay."
90 Th233 -> 91 Pa233 + ß 
The element with 91 protons is Protactinium (Pa). The isotope 91 PA 233 also
undergoes beta decay,
91 Pa233 -> 92 U233 + ß 
The U 233 isotope that is produced in step  is fissionable, but has fewer neutrons
than its heavier cousin, Uranium-235, and its fission releases only 2 neutrons, not 3.
92 U233 + 0 n1 -> fission fragments + 2 0 n 1 
Fusion Energy (how the sun gets its energy)
In a fusion reaction, two light atomic nuclei fuse together to form
heavier ones, as is shown in the figure. The fusion process releases a
large amount of energy, which is the energy source of the sun and the
Proton + neutron=deuterium
Proton + 2 neutrons=tritium
D+ T= 4 He +n + 17.6 MeV
H+ 3 H= 4 He
Fusion Inside the Stars
• Fusion in the core of stars is reached when
the density and temperature are high
enough. There are different fusion cycles
that occur in different phases of the life
of a star. These different cycles make the
different elements we know. The first
fusion cycle is the fusion of hydrogen into
Helium. This is the stage that our Sun is in.
The long-term objective of
fusion research is to harness
the nuclear energy provided
by the fusion of light atoms to
help meet mankind´s future
How do we get energy from fossil fuels?
A water turbine is a
rotary engine that
takes energy from
Boiling Water Reactor
In the boiling water reactor the same water loop serves as moderator, coolant for the core,
and steam source for the turbine.
Boiling Water Reactor
In the boiling water reactor (BWR), the water which passes over the reactor core to act as moderator and
coolant is also the steam source for the turbine. The disadvantage of this is that any fuel leak might make the
water radioac1ve and that radioac1vity would reach the turbine and the rest of the loop.
A typical opera1ng pressure for such reactors is about 70 atm at which pressure the water boils at about 285
C. This opera1ng temperature gives a Carnot efficiency of only 42% with a prac1cal opera1ng efficiency of
around 32%, somewhat less than the pressure water reactor.
Pressurized Water Reactor
In the pressurized water reactor, the water which flows through the
reactor core is isolated from the turbine.
In the pressurized water reactor (PWR), the water which passes over the reactor core
to act as moderator and coolant does not flow to the turbine, but is contained in a
pressurized primary loop. The primary loop water produces steam in the secondary loop
which drives the turbine. The obvious advantage to this is that a fuel leak in the core
would not pass any radioactive contaminants to the turbine and condenser.
Another advantage is that the PWR can operate at higher pressure and temperature,
about 160 atm and about 315 C. This provides a higher Carnot efficiency than the
BWR, but the reactor is more complicated and more costly to construct. Most of the
U.S. reactors are pressurized water reactors.