Nuclear energy

1. Pressurized Water Reactors

2. Chernobyl Accident

3. RBMK Reactor

4. Reactor Control

5. South-Ukrainian NPP

6. Zaporizzhya NPP

7. Nuclear Reactor Arrangement

8. First Nuclear Power Station

9. Types of Nuclear Power Plants

10. NPP Nuclear Safety

11. Fission Chain Reaction

12. The Arrangement of a NPP

13. Research Training Reactor IR-100

14. Reactor Classification

15. Boiling-Water Reactor

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.

Chernobyl Accident

1. Chernobyl accident took place at Chernobyl NPP on April 26, 1986 at 01:23 a.m.

2. Chernobyl power plant is located near Pripyat, Ukraine.

3. The station consisted of four reactors of RBMK-1000 type, each capable of producing 1 gigawatt (GW) of electric power

4. The four units together produced about 10% of Ukraine’s electricity at the time of the accident.

5. The construction of the plant began in 1970s, with reactor No.1 commissioned in 1977 followed by No.2 (1978), No.3 (1981) and No.4 (1983).

6. During the daytime of April 25, 1986, reactor 4 was scheduled to be shut down for maintenance.

7. The aim of the test was to determine whether the turbines in the rundown phase could power the pumps while the generators were starting up.

8. At 1:23 a.m. steam to the turbine was shut off.

9. The turbine was disconnected from the reactor increasing the level of steam in the reactor core.

10. The reactor operation became progressively less stable and more dangerous.

11. The reactor jumped to around 30 GW, ten times the normal operational output.

12. An explosion at the plant was followed by radioactive contamination of the surrounding geographic area.

RBMK

1. The RBMK channel-type uranium-graphite reactor operates as a single-loop system.

2. The steam produces in the core is directly fed to the turbine.

3. The reactor is located in a concrete well.

4. It is made of vertical graphite columns with central holes to house process channels and special channels.

5. Process channels house fuel elements and provide coolant flow.

6. Special channels house control and safety rods and also means of technological control system.

7. The core contains fuel cassettes.

8. Each cassette contains two fuel assemblies, each assembly consisting of 18 fuel elements.

9. Fuel elements are formed of fuel pellets enclosed in hermetical zirconium cans.