The V.I. Lenin Memorial Chernobyl Nuclear Power Station (Russian: Чернобыльская АЭС им. В.И.Ленина, Ukrainian: Державне спецiалiзоване пiдприємство "Чорнобильська АЕС") (51°23′21″N 30°05′58″E / 51.38917°N 30.09944°E / 51.38917; 30.09944) is in the city of Prypiat, Ukraine, 18 km northwest of the city of Chernobyl, 16 km from the border of Ukraine and Belarus, and about 110 km north of Kiev. It was the site of the Chernobyl disaster in 1986, but due to high power demand, continued to operate until December 2000. Workers still monitor the remaining three reactors at the Chernobyl plant because these reactors still contain nuclear fuel which needs to be monitored around the clock.

Construction

The station consisted of four reactors of type RBMK-1000, each capable of producing 1000 megawatt of electric power (3.2 GW of thermal power), and the four together produced about 10% of Ukraine's electricity at the time of the accident.

Construction of the plant and the city of Pripyat to house workers and their families began in 1970, with reactor no. 1 commissioned in 1977. It was the third nuclear power station in the USSR of RBMK type (after Leningrad and Kursk), and the first ever nuclear power plant on Ukrainian soil. The construction of the first reactor followed by reactor no. 2 (1978), no. 3 (1981), and no. 4 (1983). Two more reactors, nos. 5 and 6, capable of producing 1000 MW each, were under construction at the time of the accident. Reactor no. 5 was almost complete at the time of the accident and was scheduled to start operating in the fall of 1986. However, it has since been abandoned but construction cranes still stand next to it to this day.

Accidents

1982

In 1982, a partial core meltdown occurred in the reactor no. 1 at the Chernobyl plant. Due to the secret policy of the Soviet Union, the extent of the accident was not made public until years later. The reactor was repaired and put back into operation within months.

1986

See Chernobyl disaster, Chernobyl disaster effects

On 26 April 1986, a disaster occurred at reactor no. 4, which has been widely regarded as the worst accident in the history of nuclear power. As a result, reactor no. 4 was completely destroyed and has since been enclosed in the sarcophagus to prevent further escape of radiation. Population of nearby areas were evacuated. Large areas within Europe became contaminated with radiation and different kinds of cancer have been on the rise in Ukraine and neighboring Belarus, which received the greatest amount of fallout. The construction of new reactor no. 4 sarcophagus is underway.

1991

In 1991, during a scheduled shutdown, a fire broke out in one of the turbines belonging to reactor no. 2 which had caused severe damage to the reactor building. It was then decided that reactor no. 2 would not be returned to operation because of the severity of the damage.

Aftermath

Following the 1986 accident, the remaining three reactors at the plant were shut down, because the plant was highly contaminated with radiation and it was unsafe for employees to keep working in such conditions. However, after a massive cleanup inside the plant and due to the huge demand for electricity, reactor units 1 and 2 were restarted by the autumn of 1986. After a more thorough cleanup process, reactor unit 3, which was contained in the same building as destroyed unit 4, was restarted in the autumn of 1987. The town Slavutych was built to house power plant workers because Pripyat was uninhabitable due to radioactive contamination.

Decommissioning

Since 1991, western nations have been pushing Ukraine to shut down the Chernobyl plant. After the fire at reactor no. 2, it was decided that the Chernobyl plant would be taken out of service in two stages, with one of the two remaining reactors being shut down by the year 1996 and another by the year 2000. It was decided that reactor no. 1 would be shut down first for two reasons; one being that it is the oldest of the two and because too much health and money was invested into making reactor no. 3 operational just 4 years earlier that it would not make much sense to take it out of service that soon.

Unit 3 was the last reactor to be operated at the Chernobyl plant. It was functioning normally but was shut down in December of 2000. The closure of unit 3 resulted primarily from Western political pressure. Under an agreement with western nations, Ukraine agreed to close the Chernobyl plant by the year 2000. Western pressure was largely motivated by memories of the accident that occurred in 1986.

People continue to work at the Chernobyl plant until the reactor units 1, 2, and 3 are totally decommissioned, which is expected to take years. The remains of the reactor unit 4 will remain radioactive for some time. The isotope responsible for the majority of the external gamma radiation dose at the site is 137 Cs which has a half life of about 30 years. It is likely that even with no further decontamination work, that in 300 years that the gamma dose rate at the site will be close to the background level. However some of the alpha emitters are longer lived, the soil and many surfaces in and around the plant are likely to be contaminated with transuranium metals such as plutonium and americium, which have much longer half lives. It is planned that the reactor buildings will be disassembled as soon as it will be radiologically safe to do so.