Chernobyl nuclear accident, Soviet Union

Abandoned City or Prypiat,
Chernobyl nuclear accident

Chernobyl control room.
Before the nuclear accident

Current status of the control room.
Chernobyl nuclear accident

Chernoby Current Status

Chernoby Current Status

The Chernoby nuclear accident was the worst accident in the history of nuclear energy. After 30 years, Chernobyl's current situation remains delicate.

The recovery of the nuclear accident zone and the cleaning products has resulted in a large amount of radioactive waste and contaminated equipment. The generated nuclear waste is stored in about 800 different sites inside and outside the 30 km exclusion zone around the Chernobyl nuclear reactor.

These nuclear waste are partially stored in containers or buried in trenches, which can lead to the risk of contamination of groundwater.

It has been assessed that the sarcophagus and the proliferation of waste storage sites represent a source of dangerous radioactivity in nearby areas. Some experts of the NEA feared that the collapse of the injured nuclear reactor would cause serious damage in the only reactor in operation until December 15, 2000, reactor 3.

The following images correspond to the abandonment aspect of the city of Prypyat, the city closest to the nuclear power plant.

Current status in Chernobyl after the accidentaCurrent status in Chernobyl after the accidentaCurrent status in Chernobyl after the accidentaCurrent status in Chernobyl after the accidenta

Vienna International Conference

At the International Conference in Vienna, held in April 1996, it was concluded that the total rehabilitation of the area was not possible due to the existence of "hot spots" of contamination, risks of contamination of groundwater, restrictions on food and of risks associated with the possible collapse of the sarcophagus, given its deterioration in the years following the accident.

At the international conference in Vienna, it was pointed out that it was necessary to carry out a complete research program to develop an adequate design that would constitute a secure system of confinement from the ecological point of view. The new confinement of the plant should prevent the infiltration of rainwater inside and avoid the sinking of the existing sarcophagus. The sinking of the current sarcophagus would cause the escape of radioactive dust and the remains of nuclear fuel (uranium and plutonium) into the environment.

International aid programs to improve the current Chernobyl situation

In the face of the Chernobyl situation, the authorities and the nuclear industry in Western countries are making notable efforts to help Eastern countries improve the safety of their reactors, including RMBKs. At present it is affirmed that, the situation of these countries is much better than in the year 1986.

Among the European Union's aid programs, the TACIS (1989) and PHARE (1990) programs stand out. All economic contributions are transferred to a fund managed by the EBRD (European Bank for Reconstruction and Development) known as the "Chernobyl Shelter Fund (CSF)" or " Chernobyl Protection Fund". The EBRD will administer the fund on behalf of the contributing and donor countries, being accountable to the Assembly that meets 3 or 4 times a year. Currently, it has 22 members, including the European Union and Ukraine.

The TACIS Program financed, in 1996, a first study with the objective of analyzing, in a first phase, the possible short and long term measures, to remedy the deplorable situation of the sarcophagus, and finally transform it into a secure site.

Initially, there were two alternatives: to bury the sarcophagus in a concrete block and build a new enclosure that completely covered the damaged reactor 4 and reactor 3.

In May 1997, a group of European, American and Japanese experts, funded by the program, prepared the SIP (Shelter Implementation Plan). The objectives of the plan to convert the sarcophagus into a secure site were the following:

  • Reduce the risk of sinking the sarcophagus.
  • In case of sinking, limit the consequences.
  • Improve the nuclear safety of the sarcophagus.
  • Improve worker safety and environmental protection in the sarcophagus.
  • Convert the site of the sarcophagus into a safe area from the environmental point of view.

 In addition, the SIP established three milestones to achieve:

  • Strategic decision to follow regarding stability and protection.
  • Strategy to follow regarding the problem of damaged fuel and scattered inside the sarcophagus.
  • Decision of the new type of enclosure to be built.

Sacròfag in construction for the reactors 3 and 4 of the Chernobyl nuclear power plant.According to the program, the project was to be completed in 2007. Until May 2001, the stabilization tasks and other short-term measures were carried out, constituting the first phase of the SIP.

The preliminary technical studies necessary to determine a strategy to improve the safety systems of the nuclear power plant were also made and, in a second phase, the sarcophagus was prepared as a safe site.

As for the type of protective enclosure, it was finally decided to build a wide arc of metallic vault inside which the damaged unit 4 would remain. This construction offered many advantages in terms of reducing irradiation doses, safety during construction, the release of existing unstable structures, a larger space for dismantling and the flexibility needed to deal with the uncertainties of withdrawal of fuel nuclear damaged and dispersed.

This metallic vaulted arch was under construction from 2002 and 2005, at a cost of 700 million dollars. The sarcophagus will house the units of the nucellar reactors 3 and 4 of the Chernobyl nuclear power plant, under its internally pressurized double walled waterproof wall and with a foundation depth of 27 meters.

Unit 3 of the Chernobyl plant stopped definitively on December 15, 2000. Both Ukrainian and foreign experts set the cost of closing between 2,000 and 5,000 million dollars, until the radioactive fuel left in the plant is removed with deadline in 2008. This decision completed the total closure of the nuclear facility that had led, on April 26, 1986, to the largest nuclear catastrophe in the history of nuclear energy.

 

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Last review: May 25, 2017