1. Nuclear Energy Production Nuclear energy is a form of energy that has both environmental and economic benefits and problems. The uniqueness and complexity of all the processes that produce nuclear fuel and use it to generate electricity have led to both major benefits and social controversy.

2. What IS Radioactivity When atoms are created by nature, some of them are put together in an unstable way, like a very tall Jenga tower---it wants to fall apart. Instead of falling apart all at once, it falls apart piece by piece. As the particles leave, they fly through space to be absorbed by other atoms, or just decompose naturally.

5. Nuclear fission produces heat when neutrons are used to bombard heavy atoms such as Uranium.

6. Nuclear power is produced in reactors.

7. What is in a nuclear reactor? Nuclear Fuel- mostly enriched Uranium although some reactors use natural Uranium. Moderators such as water or heavy water are used to control the speed of the neutrons and therefore keep nuclear reactions at a steady pace. Coolants such as water or heavy water serve to absorb and take away the heat from the fission reaction.

8. Control rods are inserted or withdrawn from the core of a nuclear reactor to control the rate of reaction or even to halt the reaction. Basically, putting IN the control rods stops the reaction, taking them OUT starts the reaction—they attract the neutrons so they do not get attached to the uranium.

9. The containment structure protects those outside from the effect of radiation exposure in case of a malfunction inside. The containment structure is only as good as its thickness and the material it is made of. Many old structures are leaking radiation.

10. Uranium provides the energy source for nuclear reactors. 1 ton of uranium has the equivalent energy of 20,000 tons of coal!

11. Our sun is a large source of radiation. Radiation is energy that travels through space.

12. Review- UV-mostly absorbed by the atmosphere

13. Neutrons: A Form of Ionizing Radiation Neutrons are particles produced by the decay of some radioactive substances or through a process called nuclear fission. Some neutrons are high energy, fast moving particles while others are low velocity low energy particles.

14. Radiation is not to be feared. Radiation safety is essential for its proper usage. Knowing the nature of a source of radiation, the source location and its intensity allows us to take advantage of nuclear materials without subjecting ourselves and others to the negative consequences we fear.

15. Radiation is all around us. For example the Aurora Borealis visible in the northern latitudes is the result of the interaction of cosmic radiation from outer space with the outer layers of the atmosphere. Many man-made products contain radioactive materials. Smoke detectors use Americium- 241 to trigger a sound alarm. Americium-241 detects smoke in the air.

16. Many radionuclides are very useful. Here are some of their uses: Uranium-238 4.5 billion years Color brighteners in dental fixtures; dating old rocks Iodine-129 15.7 million years Check radioactivity counters at in-vitro diagnostic labs Carbon-14 5730 years Test new drugs for harmful by-products; Carbon dating of ancient artifacts

17. The Key is Safety While the atom can be safely harnessed, it takes knowledge of the consequences of radiation to do so. A person, however, does not become radioactive by exposure to radiation. X-rays will not make you glow in the dark.

18. Main environmental pathways of human radiation exposure

20. The Hanford Site has 53 million gallons of high level nuclear waste mostly stored in underground tanks.

21. Commercial Waste In the US, commercial nuclear activities generate spent fuel rods that are held for disposal at reactor sites until a commercial waste repository is available. Low level waste (Classes A, B, and C) depending on the level of radioactivity are sent to low level waste landfills. Some materials can be recycled.

22. In many other countries the spent fuel is reprocessed to obtain additional energetic value. This is economical today and is certainly more effective than a once- through fuel usage cycle.

23. Aboveground storage—can you think of a potential problem?

24. Low-level clean-up—can you think of a potential problem?

25. Underground storage-can you think of a potential problem?

26. So what went wrong at Fukishimo? The water cooling system around the reactors broke, sending thousands of gallons of radiated water into the environment. There is still no cooling water around the reactors. The plan is to move them to a new reactor plant…somehow…..someday….