Question

heat produced by nuclear fission is carried away by (24)____, which enters the core at point (25)__ in the diagram. it then leaves the core at point (26)__. heat from the reactor core is used to boil water in the (27)__, shown at (28)__ in the diagram. steam produced here is used to generate electricity at point (29)__ in the diagram. the steam is then cooled at location (30)____ by water from an outside source. for each statement, write true or false. 31. a nuclear reactor produces energy from fuel rods containing uranium - 238. 32. the amount of energy produced for each kilogram of uranium is about the same as the amount of energy from a kilogram of coal. 33. the only elements that can be used as fuel in a nuclear power plant are those in which a chain reaction can occur. 34. if more than a critical mass is present in a sample, that sample is said to have supercritical mass. 35. water is the most common coolant used in a nuclear reactor. 36. nuclear power plants usually produce electricity. 37. the purpose of the control rods in a nuclear reactor is to reflect neutrons back into the core. 38. the production of energy in a nuclear reactor can be stopped by pulling out all control rods. 39. a breeder reactor produces more fuel than it uses. 40. the fission products produced in nuclear power plants are not radioactive. 41. an uncontrolled chain reaction led to the nuclear accident in chernobyl, ukraine.

Explanation:

1. Nuclear reactors mainly use uranium - 235, not uranium - 238 for fission.
2. Uranium produces far more energy per kilogram than coal.
3. Only elements with a self - sustaining chain reaction can be nuclear fuel.
4. A sample with more than critical mass is supercritical.
5. Water is a common coolant in nuclear reactors.
6. Nuclear power plants are designed to generate electricity.
7. Control rods absorb neutrons to regulate the reaction, not reflect them.
8. Pulling out control rods increases reactivity, inserting them stops it.
9. Breeder reactors produce more fissile material than they consume.
10. Fission products in nuclear power plants are radioactive.
11. An uncontrolled chain reaction caused the Chernobyl accident.

Answer:

1. false
2. false
3. true
4. true
5. true
6. true
7. false
8. false
9. true
10. false
11. true