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

Current situation in Chernobyl

Current situation in Chernobyl

The recovery of the accident area and cleaning products has resulted in a large amount of radioactive waste and contaminated equipment, stored at about 800 different sites inside and outside the 30 km exclusion zone around the nuclear reactor 4 from Chernobyl.

These nuclear wastes are partially stored in containers or buried in trenches, which may lead to a risk of contamination of groundwater.

The sarcophagus and the proliferation of waste storage sites have been assessed as a source of hazardous radioactivity in nearby areas, and some NEA experts feared that the sinking of the failed reactor would cause serious damage to the only operating reactor Until 15 December 2000, the reactor 3.

The following images correspond to the appearance of abandonment that currently has the city of Prypyat, the city closest to the nuclear power plant.

Estado actual en Chernobyl después del accienteEstado actual en Chernobyl después del accienteEstado actual en Chernobyl después del acciente

 

Vienna International Conference

At the Vienna International Conference in April 1996, it was concluded that total rehabilitation of the area was not possible due to the existence of "hot spots" Pollution, groundwater contamination risks, food restrictions and risks associated with the possible collapse of the sarcophagus, given its deterioration in the years following the accident. It was pointed out that it was necessary to carry out a complete research program to develop an adequate design that would constitute an ecologically safe containment system, avoiding rainwater leaks inside and avoiding the collapse of the existing sarcophagus, Which would lead to the escape of radioactive dust and nuclear waste (uranium and plutonium) into the environment.

International aid programs

In the face of this situation, the authorities and the nuclear industry in Western countries are making significant efforts to assist the Eastern countries in improving the safety of their reactors, including RMBK, and it can be said that the These countries is much better than in 1986.

The European Union's aid programs include TACIS (1989) and PHARE (1990). 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) & rdquo; Or "Chernobyl Protection Fund". The EBRD will manage the fund on behalf of contributing and donor countries, being responsible to the Assembly that meets 3 or 4 times a year. At present, it has 22 members, including the European Union and Ukraine.

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

Initially, there were two alternatives: to bury the sarcophagus in a concrete block and to construct a new enclosure that completely covered the uneven reactor 4 and the 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 as follows:

  • Reduce risk of sarcophagus subsidence.
  • In case of collapse, limit consequences.
  • Improve the nuclear safety of the sarcophagus.
  • Improve worker safety and environmental protection in the sarcophagus.
  • Converting the sarcophagus site into an environmentally safe area.

In addition, the SIP set three milestones to achieve:

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

Sacròfag in construction to cover 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, stabilization and other short-term actions were carried out, constituting the first phase of the SIP. Preliminary technical studies were also carried out to determine a strategy to improve security systems and to prepare the sarcophagus as a safe site in a second phase.

As for the type of protection enclosure, it was finally decided to construct a wide arch of metallic vault inside which would be damaged unit 4, since it offered many advantages in the reduction of the doses of irradiation, the security during the construction , The release of existing unstable structures, greater space for decommissioning and the flexibility needed to deal with the uncertainties of withdrawal of damaged and dispersed fuel.

This metallic vaulted arch, under construction from 2002 to 2005, costing $ 700 million, will house units 3 and 4 of the Chernobyl plant, under its waterproof wall of double wall internally pressurized and with a foundation of 27 meters deep.

Unit 3 of the Chernobyl plant was definitively stopped on 15 December 2000. Both Ukrainian and foreign experts fixed the cost of the closure between $ 2 billion and $ 5 billion, until the radioactive fuel left in the With a deadline of 2008. This decision completed the complete closure of the nuclear facility that had given rise to the largest nuclear catastrophe in the history of nuclear energy on 26 April 1986.

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Last review: May 25, 2017