March 12 th
Go beyond 310 for the media critique. Media article comparison. Critique and compare.
One covers the topic well. One of them ignores them. Compare them scientifically. Use
Largely associated with high energy small particles.
1. Radioactivity – spontaneous disaggregation of a nucleus. Largely associated with the release of
high energy small particles. Different types of radioactive particles including alpha particles with
a helium nucleus.
a. Eg: radium , can decay spontaneously gives you radon + helium nucleus
b. Alpha particles are really safe, but if you ingest them it is dangerous. It
c. Barium particles are energy electrons generally arises when neutrons breaks into
protons and high energy electrons.
d. Radioactive Pb: The atomic no is higher than Pb because one of the neutrons have
decayed into a proton and a high energy electron.
e. The electrons have more energy.
f. Most energetic is gamma rays which are very very high energy rays and are emitted at
the same time. they are the most damaging of all.
g. Much of gamma occurs through the barium particle ionization. The electron goes in The
body sees water , ionizes it and it break apart, the proton + the ionized water then
falls apart into proton + OH.
h. So you can have low level of radiation have higher level of affect high level of
radiation particlualry when cells are multiplying and when changes are occurring so
that damaging ?
a. All are physically ?
b. The starting point is rad, and 0.1 J/ kg about body tissue. This is the amount of energy
that anyone possesses into a body tissue
c. More interesting quantity is called the REM = renquant equivalent mass this
accounts to the biological effectiveness of that radiation
d. The way you arrive at a REM is, you take a RAD and you multiply it by biological
efficiency. And the alpha particle has a factor of 10 and favors and gammas have a
factor of 1 for biological tissues.
e. So if you get an alpha particle inside of you: radon is a gas, and if you breathe in and
disintegrates inside you and then you have the ability of delivering radiation into your
body which has high efficiency. It will have a higher dose in your body.
f. The modern units is a sever, the abbreviation for that is a SV, which is equal for 100
REMs. g. The currnet average was 3 milli severs per year of radioactive dose. 55% of that is from
radons. Radons is a gas, and much of it comes from smoking or release from ventilation
tight houses. So you have to be careful of rocks which have radioactive materials in
h. Radons itself is half way short. 24 days. It is largely a water proof. Knock gases, and
these become particles, etc.
i. Most of them are taken from radon gases
j. 3% csomic rays ?
k. Natural high energy particles coming through the atmosphere, how long pilots can fly
blah, 10% come from natural radiacotive radiations coming from the bottom.
l. You get about 20% on average from extras. High energy photons.
m. This is all very low level, and by contrast, if you get exposed to 5 severs then , roughly
thousand times much, half of you is going to die in weeks. So this is very low level
compared to very high level.
3. Radons is thought to cause around 2000 deaths / year in canada. Just from natural radon
a. This is from very low study,
b. Canada used to have the largest underground radium mines.
c. They looked at the health of these miners and looked at their smoking rates, and death
from lung cancer, and then analyzed their doses on exposing. And the death is like
2000 deaths / year. Then when you realize that there is a natural death, then you have
to ask what is the force of this nuclear exposure?
4. How do we get energy out of this conduct.
a. There are two processes
i. Fusion – fusing things together and then you get energy from joining them
ii. Fission – The process which gives us most of the power we have now. Globally
17% of electricity comes from fission. Total energy is like 7-8%. Sometimes in
countries it is huge. Japan used to have lots of nucleic power, now they don’t
have that much. Frnace – 80%. Etc.
b. How do we get that much amount of electricity?
i. Power plant
1. Heat source expand steam heat water get across turbines
c. How do we get heat?
i. All comes down from one reaction! You take uranium 235 isotope and a
neutron and, then the neutron gets absorbed by the uranium isotope and
fission breaks apart into form two daughter products and two barium
nucleuses(which are radiocactive), and a krypton nucleus + three high energy
ii. The main point in nuclear power is you get those neutrons out, and you get a
lot of energy, because this allows for a chain reaction. iii. The way that power plan works is that exactly one of these neutrons is used to
fission another uranium isotope.
iv. And other neutrons are power is absorbed and taken away. If you use less than
one neutron to fission to uranium, then you don’t get a chain reaction.
v. If you let all the neutrons to proceed, and you have enough uranium to get you
around, then you get along?
vi. There is a difference between the bong And a power plant. And in a bong has
have 90% uranium 235 present. The natural abundance of uranium is 27% -
35%, 99.3% - 38%.
vii. Bongs typically have like 90%-35%. Most commercial reaction don’t have no
more than 3%.
viii. If you don’t have the high enough density of U 235then it gets the same as the
reaction in the bong.
ix. Bong is associated with the fact that centrifuge drives the separate concentrate
uranium and tries to get to higher levels. You have to do this anyway for
commercial power of energy.
x. There are different components of how power nuclear works.
5. Why do you need to control how many neutrons are going back?
a. The control rods are made out of cadmium (example) and they are actively controlled,
and they are essentially dipped in and out to expose more or less to the fuel, to control
the amount of neutrons allowed to fission with uranium.
6. If all the power goes out, the control rods mechanically falls into the reactive. And there are no
power to get into the reacrive because of t