Boiling-Water Reactors

Date: 2015-10-07; view: 651.

Pressurized-Water Reactors

1. A pressurized-water reactor is that in which the coolant is under high pressure.

2. It uses uranium fuel enriched with U-235.

3. A constant flow of water passes through the core of this reactor.

4. A high pressure prevents the water from boiling at high temperatures.

5. The water flows through the heat exchanger and back to the reactor in a closed system of pipes.

6. In the heat exchanger heat is transferred to a low-pressure water of the secondary system.

7. This water is converted into low-pressure steam.

8. This steam drives a turbine that turns an electric generator.

9. The ease of operation is the main advantage of PWR.

10. The disadvantage of PWR is that most of them produce wet steam which causes erosion.

1. A boiling-water reactor is that in which coolant boils in the reactor core to produce steam.

2. The steam is led directly to the turbine.

3. The heat exchanger is eliminated here.

4. The construction of a BWR is simpler and less expensive.

5. The high pressure is also eliminated, so the reactor doesn't need a very heavy and strong construction.

6. The coolant remains longer in contact with fuel elements.

7. That is why water is a more effective coolant.

8. Pumps are eliminated because of natural coolant circulation.

9. The BWR uses a low cost fuel like natural or slightly enriched uranium.

10. A disadvantage is that the steam is radioactive and this results in corrosion and shielding problems.