The First Nuclear Power Station in the World

Date: 2015-10-07; view: 521.

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.

1. The first electric power station working on nuclear fuel was built in the USSR in Obninsk by а team of scientists and engineers under the guidance of Igor Kurchatov in 1954.

2. The main purpose of the first NPS was to make sure of technical feasibility of converting nuclear energy into electrical one.

3. The reactor of the station was а uranium-graphite reactor of the channel type, water cooled.

4. The reactor core had the shape of а cylinder 150 cm high and 70 cm in diameter. It housed 128 fuel rods and 22 control rods, four of them were used for emergency cases.

5. The moderator was graphite in the form of а triangular lattice.

6. The double-circuit system produced superheated steam at the temperature of 280°С and the pressure of 12 atm. for а conventional turbine.

7. Heat capacity of the reactor was 30 MWt.

8. Four circulating pumps of centrifugal type circulated coolant through the primary circuit to four steam generators.

9. The biological shielding of the reactor was а layer of water one meter thick and а concrete wall 3 meters thick.