1. Nuclear Processes

2. Learning Target Radioactivity
Understanding the difference between a nuclear
process and a chemical reaction
Define radioactivity
Differentiate between alpha, beta, gamma radiation
Radioactive by Imagine Dragons 3 min
LecturePLUS Timberlake

3. Radioactivity
One of the pieces of evidence for the fact that atoms are made of smaller particles came from the work of Marie Curie ( ).
She discovered radioactivity, the spontaneous disintegration of some elements into smaller pieces.

4. Nuclear Reactions vs. Normal Chemical Changes
Nuclear reactions involve the nucleus
The nucleus opens, and protons and neutrons rearrange
The opening of the nucleus releases a tremendous amount of energy that holds the nucleus together – called binding nuclear energy
“Normal” Chemical Reactions involve electrons, not protons and neutrons

5. When atoms give off radiation (energy) they will ultimately become stable – non-radioactive.

6. Radiation cannot be felt, seen, heard, tasted, or smelled.

7. Radioactive decay occurs when:
Unstable nuclei rearrange their protons and neutrons
Elements with atomic # above 83 are radioactive.
3 types of particles are emitted: alpha α, beta β, and gamma γ.

8. Types of Radiation
Alpha radiation -- helium nucleus (2 protons and 2 neutrons)
Beta radiation –electron
Gamma radiation – high energy x-ray

9. Penetrating Ability

10. What can stop alpha, beta, gamma radiation?
min.
LecturePLUS Timberlake

11. Two types of nuclear processes
Fission
(radioactive decay refers to a natural fission process)
and
Fusion
There are two nuclear processes that you need to be familiar with – Fission and Fusion.

12. Understand the difference between the two
Learning Targets
Understand the difference between the two
nuclear processes fission and fusion
LecturePLUS Timberlake

13. Nuclear Fission Fission is the splitting of atoms
These are usually very large atoms, so they are inherently unstable
Fission chain has three general steps:
1. Initiation. Reaction of a single atom starts the chain (e.g., 235U + neutron)
2. Propagation. 235U fission releases neutrons that initiate other fissions
3. Termination.

14. Fission Bomb Design Little Boy U-235 Fat Man Pu
These 2 fission bombs were detonated over the cities of Hiroshima (8/6/1945) and Nagasaki (8/9/1945)
during WW11. Aftermath was devastating.

15. This photograph shows the stone steps of the main entrance of Sumitomo Bank which
is only 250 meters from the hypocenter. It is believed that a person sat down on the steps
facing the direction of the hypocenter, possibly waiting for the bank to open. By a flash of the
heat rays with temperatures well over a 1,000 degrees or possibly 2,000 degrees centigrade,
that person was incinerated on the stone steps.
Up to about 10 years after the explosion, the shadow remained clearly on the stones,
but exposure to rain and wind has been gradually blurring it. So, when the bank was newly
built, the stone steps were removed and are now preserved at the
Hiroshima Peace Memorial Museum.

18.
History channel Tsar Bomba 8min
Hydrogen Fusion Bomb

19. A Fission Reactor https://www.youtube.com/watch?v=MGj_aJz7cTs
Inside a nuclear fission reactor 4min

20. Excessive heat can not be contained
Nuclear Fusion
Fusion
Excessive heat can not be contained
Attempts at “cold” fusion have FAILED.
“Hot” fusion is difficult to contain
Taylor Wilson – Star in a Jar nuclear fusion for energy 3.35 min

21. You will be able to identify common everyday
Learning Target
You will be able to identify common everyday
uses that involve nuclear processes; radiation,
radioactive decay, nuclear fission
LecturePLUS Timberlake

22. Every Day Uses of Radioactive Materials and Radiation
Radiation is used every day in our daily lives. Following are some examples.

23. Non-destructive testing
Radiation is used to detect tiny cracks that might exist in plane engine turbine blades much like an x-ray is used to detect broken bones in a person. This is called radiography.

24. Carbon Dating – uses Carbon-14 to estimate age of organic (once living) material
Carbon 14 dating of an artifact. Carbon 14 is a naturally radioactive isotope of carbon. Any thing that was or is living has Carbon 14 in it. By measuring the amount of Carbon 14 that is still left in the artifact that was made out of something that was once alive, its age can be accurately estimated.

25. Locating a pipeline leak
A radioactive tracer was placed in a pipeline to allow workers with Geiger counters to find a leak.

26. Space batteries otherwise known as RTGs (radioisotope thermoelectric generator)
Ulysses Satellite – studied the Sun
The next Mars Rover – about the size of an SUV
An astronaut working with a battery.
Apollo missions to the Moon

27. Medical Uses Picture things Measure things Destroy things Power things
Picture things: x-rays, MRI – magnetic resonance imagining (used to be call NMRI – nuclear magnetic resonance imaging), bone scans – a radioactive tracer is injected into a patient’s blood, allowed to travel for a few hours and then an image of the area of concern is taken.
Measure things: thickness of a bone or tissue, bone density
Destroy things: radiation is used to destroy cancer cells! (It can cause some kinds of cancer and is also used to kill it!)
Power things: pace makers are powered with a plutonium battery that lasts about 5 years

28. Picture things like in an x-ray
Measure things like in bone scans or brain scans
Power things like a pacemaker
Destroy things like in radiation treatment of cancer
Medical uses of radiation – picture things like an x-ray machine, measure things like in a bone scan when blood activity is measured to see if bone cancer is present or measure brain activity for various studies, destroy things like in the radiation treatment of cancer, power things like a pacemaker which is powered by a radioisotope battery

29. Radioisotopes in Medicine
1 out of every 3 hospital patients will undergo a nuclear medicine procedure
24Na, t½ = 14.8 hr, b emitter, blood-flow tracer
131I, t½ = 14.8 hr, b emitter, thyroid gland activity
123I, t½ = 13.3 hr, g-ray emitter, brain imaging
18F, t½ = 1.8 hr, b+ emitter, positron emission tomography
99mTc, t½ = 6 hr, g-ray emitter, imaging agent
Brain images with 123I-labeled compound
23.7

30. Irradiation of Food the process of exposing food to high levels of radiation to destroy microorganisms, bacteria, and insects that might be present in the food

31. Kills bacteria which slows the ripening and sprouting of fruits and vegetables.
These onions and potatoes are all the same age. The only difference is the ones on the left have been irradiated (exposed to high levels of radiation) to kill the bacteria that cause food borne illness, ripening and sprouting.

32. Chemistry In Action: Food Irradiation
Dosage
Effect
Up to 100 kilorad
Inhibits sprouting of potatoes, onions, garlics. Inactivates trichinae in pork. Kills or prevents insects from reproducing in grains, fruits, and vegetables.
100 – 1000 kilorads
Delays spoilage of meat poultry and fish. Reduces salmonella. Extends shelf life of some fruit.
1000 to 10,000 kilorads
Sterilizes meat, poultry and fish. Kills insects and microorganisms in spices and seasoning.

33. Food IS NOT radioactive after it has been irradiated
Food IS NOT radioactive after it has been irradiated. Irradiation just kills the living things inside the food.
A food irradiation facility. The potatoes, in this case, are brought in on a conveyor belt. The room is closed off with shielding and the radioactive source is lifted out of its housing below water for the proper period of time. The source is then returned to its housing under water and the food goes on its way while more is brought in for irradiation.

34. No dairy products – irradiation activates the enzyme that makes it smell sour.
A list of food items that are currently irradiated. Notice dairy products are not listed. Irradiating dairy products causes the enzyme that makes them smell sour to activate. So, while the dairy product is still fine to consume, it would smell pretty bad.
Spices found in your kitchen right now have very likely been irradiated.

35. Did you know bananas are radioactive?
Check the peel next time you eat one!
The warning signs you see on the inside of banana peel because it contains a radioactive substance. (Not really!) All bananas have a naturally occurring radioactive isotope of potassium (Potassium 40) in them. This does not make them unsafe to eat!

36. Irradiating food could DRAMATICALLY reduce food poisoning and massive food recalls.
Information about salmonella bacteria which is found in chicken. Numbers of poisonings and deaths are probably low because symptoms are very similar to the flu.

37. No bacteria = no eye infection or worse!
Make-up is irradiated.
No bacteria = no eye infection or worse!
A list of countries who irradiate food. While the U.S. is on the list, its irradiation of food is highly limited due to lack of education and acceptance of the general public. Irradiating food could prevent and nearly eliminate food borne illnesses caused by e-coli, trichinosis, and salmonella not to mention increase the shelf life of the foods.

38. Beyond irradiating food to make is safer and last longer, irradiation is commonly used (even in the U.S.) to sterilize various products and supplies. You would not want to put mascara near your eye that had not been irradiated to kill the bacteria in it. You would likely wind up with an eye-swollen shut rather than looking attractive.

39. Nuclear Powered Aircraft Carriers and Submarines
An aircraft carrier that is powered by two nuclear reactors. The carrier can outrun all its accompanying ships that are powered using gasoline or diesel engines. Its top speed is upwards of 35 knots (over 40 miles per hour) – the actual speed is classified. Pretty fast for a ship that weighs over 97,000 tons!

40. Radiation and You

41. Some sources of radiation you might have around you on a given day.

42. Background radiation due to various activities or based on where you live.

43. Background radiation based on where you work
Background radiation based on where you work. Note: The value given for an x-ray technician is higher than current exposure rates. This has been greatly reduced with advances in shielding and focusing the x-ray beams.

44. Natural background radiation based on the state you live in
Natural background radiation based on the state you live in. These vary due to elevation differences and land formation differences.

45. Radiation Protection Factors
Time
Distance
Shielding
Quantity
A reduction in the amount of time a person is exposed to radiation reduces their dose. Radiation decreases according to the inverse square law as it relates to distance. What this means is, if you double your distance from a radiation source, your dose will be one quarter as much. If you triple your distance, your dose will be one ninth as much. If you quadruple your distance, your dose will be one sixteenth as much and so on. The use of shielding or something between you and the radioactive source protects you from exposure. The amount of radiation or radioactive substance involved in your exposure also has an effect. The smaller the source, the lower your dose.

46. All substances are poisons. There are none which is not a poison
All substances are poisons. There are none which is not a poison. The right dose differentiates a poison and a remedy.
Paracelsus
A quote from an ancient wise man. The amount of any substance is what determines if it will be a poison or a remedy. Otherwise summed up with the following statement: “the dose makes the poison”.