1. Nuclear Energy Power Plants

2. Chernobyl

3. Fuel  Uranium-235  an isotope of naturally occurring uranium- 238  Uranium is mined-common mineral is urananite.  Uranium-238 is enriched so more of the isotope U-235 is present.  Enriched from about 0.7% in naturally occurring uranium to 5% for use in reactors

4. Uranium Reserves in the United States

5. Fuel Rods in the Reactor Core  The fuel rods in a reactor are about a finger width in diameter.  They are 12 feet long  100 fuel rods make up a fuel rod assembly (fra)  There are 100 fra in a reactor core

7. What happens in the Reactor? Chain Reaction

8. Another view of a Chain Reaction

9. Chain Reactions in Fission Nuclear Reactors  Our present day Nuclear Power plants are fission power plants.  What does fission mean? The atom is split apart to produce energy.  A controlled chain reaction takes place within the reactor core.

10. Can a reactor become a Nuclear Bomb?  No, the uranium used in a nuclear bomb must be U-235 enriched to 95%.

11. Can a reactor sustain damage that results in the release of radiation?  Yes Two examples: Three Mile Island (1979) and Chernobyl (1986)  In both cases radiation was released into the atmosphere.  Both were caused by human error

12. How is a chain reaction controlled?  Control Rods-made of cadmium and boron.  They absorb neutrons to help control a reaction. If we drop more control rods into the reactor core, what will happen to the reaction rate? SLOW IT DOWN!

13. What else helps to control the reaction?  Water present in the reactor core slows down the movement of the neutrons in the chain reaction.  It also absorbs heat energy.

14. Safety  Containment Domes- Building that encloses the reactor and helps to contain any radiation leaks should they occur.  Four (4) foot thick wall of cement.

15. Reactors in the United States History  First active reactor in the Unites States to produce electricity 1957  As of 1990 there are 111 operating units producing about 20% of the total electricity generated in the United States.

17. Boiling Water Reactor (BWR) Single loop

18. Pressurized Water Reactor (PWR) Double loop system

19. Minnesota Nuclear Power Plants How many are there in Minnesota Answer: 2 Where are they located? Answer: Monticello and Prairie Island What kind of reactor are they? Answer: Monticello is a BWR and Prairie Island is a PWR

20. How much power do they provide? about 40%