The key parts of a nuclear reactor include the fuel, fuel rods, and control rods. The fuel is made of enriched uranium dioxide pellets contained within metal fuel rods bundled together. Control rods made of boron are raised or lowered to control the rate of the nuclear chain reaction. A moderator like water or heavy water is used to slow fast neutrons released during fission so that the reaction is sustained. A cooling system removes heat from the reactor core using coolants like water that are circulated through the reactor.

2. needed in all energy-producing processes

3. heart of the reactor

4. the fuel consists of pellets of enriched uranium dioxide (mostly in US power plants)

5. FUEL RODS

6. A 12-foot-long metal tubes

7. Container of the fuel pellets

9. CONTROL RODS

10. lowered or raised next to the fuel assembly to speed up or slow down the rate of the chain reaction by absorbing some of the neutrons released in fission

11. use the element boron to absorb neutrons

13. Removes the heat from the reactor and keeps the core at a proper temperature

15. excellent resistance to high temperatures and high levels of radiation

16. non-corrosive

17. high boiling point for liquids

18. low melting point for solids

19. be easily circulated by a pump.

20. In large reactors, as much as 330,000 gallons of water coolant flow through the reactor core every minute. The water that leaves the reactor is sent to either cooling towers or discharged into large bodies of water such as cooling ponds, lakes, rivers, or an ocean.

21. Moderator

22. Slowed down the fast neutrons which are released from a nuclear fission

23. Fast moving neutrons strike the moderator material, which is not efficient at absorbing them, and slows them down.

24. Moderators are made of various materials. Water is an excellent moderator because the water can also serve as a coolant. Normal water, known as “light water,” is used in most reactors simply because it is cheap and abundant. The only downside to using light water is that reactor fuel must be enriched when water is the moderator.

25. Another moderator material is deuterium, also known as “heavy water” because it has an extra hydrogen atom. Deuterium is costly to manufacture, but it does not require fuel to be enriched. Other moderator materials are graphite and beryllium, which are used in different types of reactors. <br /> <br />