Chernobyl Disaster Timeline 1970-Present Day

Work began constructing a new nuclear power plant at Chernobyl. A new town, Pripyat, to house workers at the plant, was also constructed.

It was decided that a RBMK (boiling water reactor) would be built. Although it produces more radiation than other reactors it produced cheaper electricity and was felt to be safer.

The cooling water reservoir was filled.

The Chernobyl nuclear power station became operational with one reactor.

A second reactor became operational.

Pripyat was proclaimed a city.

A partial core meltdown happened in reactor 1 but it was kept quiet.

Construction of reactor number 4 was completed.

Reactor number 4 became operational.

The Chernobyl site contained four 1000-megawatt reactors. A further two reactors were being constructed.

Operators began reducing the power of reactor number 4 prior to a routine safety test.

Reactor number 4’s emergency core cooling system was disabled prior to the safety test.

The safety test was delayed due to the power requirements of the area as a result the power reduction was halted and remained at 50%.

Night staff at Chernobyl were given permission to test and shutdown reactor number 4. However, the staff were inexperienced and not familiar with the test.

The power level of the reactor fell to dangerous levels due to an operator failing to set the power reduction limit to 30%. The operators decided to remove a number of the reactor’s control rods in a bid to raise power. This failed.

The power level in reactor 4 stabilised but was still too low. Despite this, the test went ahead.

There was a power surge in the reactor.

The emergency shutdown button was pressed but the control rods jammed. The power surged and the graphite ends of the rods ignited.

A huge explosion blew the 1,000 ton roof off the reactor. Radiation was released together with dust and graphite. Walls collapsed and fires broke out. The engineer in charge mistakenly believed that reactor number 4 was still intact.

Firefighters arrived at the scene. They were not aware that there was a radiation leak and did not have protective clothing.

Following the explosion, a crowd of people had gathered on a railway bridge outside Pripyat to watch the spectacle. All died from radiation poisoning.

Police officers were sent to stop cars from leaving or entering the city of Pripyat. The officers were not issued with protective clothing.

Reactor number 3 was shut down.

A total of 186 firefighters had managed to put out most of the fires. However, the reactor core was still alight.

Despite the disaster, work was not halted on the construction of two new reactors and the three remaining reactors remained operational.

It was decided that it was not necessary to evacuate Pripyat.

Reactors number 1 and 2 were shut down.

General Pikalov measured the radiation levels at the site and stated that massive levels of radiation were being emitted.

Helicopters began dropping sand, clay, boron, lead and dolomite into the burning core in an attempt to minimise radioactive emissions. This went on for four days.

Radiation levels dropped slightly and evacuation of Pripyat was delayed.

Radiation levels rose again and the residents of Pripyat and other towns and villages within a 6 mile radius were evacuated. They had not been told of the reactor explosion and were told the evacuation would be temporary.

Swedish air monitors detected radiation in the atmosphere. It was traced to the Soviet Union. When questioned Soviet officials admitted there had been an incident but stated it was under control.

An announcement was made on Russian TV that an accident had happened at the Chernobyl plant.

US spy satellite photos showed the extent of the damage caused by the nuclear explosion.

Russian television news stated that two people had died in the explosion and that people had been evacuated from Pripyat and other nearby towns. The severity of the accident was played down.

Even though the wind was blowing towards Kiev, the annual May Day parade was not cancelled. Soviet authorities wanted to avoid a panic,

Liquid nitrogen was pumped under the remains of reactor number 4 in an attempt to cool it down. A huge workforce began cleaning up the area by bulldozing villages, destroying pets and livestock and burying contaminated soil.

The level of radioactive emissions dropped. Schools in Kiev were closed and residents told to remain indoors.

20,000 tons of radioactive water had been drained from underneath the reactor core.

Concrete was pumped under the reactor prior to it being encased in concrete and metal.

Volodymyr Pravik, one of the first firemen to arrive at the disaster, died of radiation sickness.

Aleksandr Akimov, night supervisor at reactor 4 on 26th April, died of radiation sickness.

Soviet leader, Mikhail Gorbachev, finally broadcast to the people. He stated that the worst was over.

It was decided that a concrete structure should be built over the reactor.

The management team of Reactor number 4 were dismissed for irresponsibility.

Chernobyl Director Victor Bryukanov was put on trial by the Politburo. Bryukanov was sentenced to 10 years imprisonment. He was released in 1991 due to suffering severe effects of radiation poisoning.

A report into the accident blamed careless, mismanagement and violations of safety for the disaster.

Reactor number 1 was restarted.

Construction work on reactors 5 and 6 resumed.

Reactor number 2 was restarted.

The concrete and metal cover, known as the sarcophagus, over the reactor was completed.

Filmmaker, Vladimir Chevchenko who filmed the early stages of the disaster, died from radiation poisoning.

Reactor number 3 was restarted.

Construction work on reactors 5 and 6 was halted.

It was decided not to complete the building of reactors 5 and 6.

Reactor number 1 was shut down.

There was a fire in the turbine hall of reactor number 2.

Reactor number 2 was shut down.

Reactor number 3 was shut down.

A contract for a New Safe Confinement shelter over reactor number 4 was signed with French company, Novarka.

The Emergencies Ministry of Ukraine deemed it safe for tourists to visit Chernobyl and began licensing tours.

A court in Kiev banned tours to Chernobyl claiming that permission must be given by the Interior Minister.

Pripyat was opened to tourists.

The New Safe Confinement was nearing completion as the two halves of the enormous structure were brought together.

The New Safe Confinement was completed.

A solar power plant was opened at Chernobyl.

Following the Russian Invasion of Ukraine, Russian troops took control of the Chernobyl plant.

Russian forces disconnected Chernobyl from the power grid. Without power, the plant is unable to cool spent nuclear fuel posing the threat of a radiation leak.

It was reported that Russian troops had left Chernobyl.