Chernobyl: What was the accident like?
The Chernobyl accident was a combination of a faulty design of the nuclear power plant, which did not have a contentment enclosure, and the mistakes caused by its operators.
The lack of a “safety culture”, which in itself was a consequence of a lack of a democratic political and social regime at the Soviet Union, is at the root of the Chernobyl accident.
The design of a RBMK reactor would never have been authorized in Western countries
Causes
The Chernobyl accident was a combination of a faulty design of the nuclear power plant, which did not have a contentment enclosure, and the mistakes caused by its operators, who voluntarily disconnected several safety systems in order to carry out an experiment within an environment where training was scarce, and without an independent regulatory body.
The Soviet Union did not have an independent system for the inspection and evaluation of safety at nuclear sites – that is to say, a regulatory body - as did countries in the Western block.
The design of a RBMK reactor would never have been authorized in Western countries. In fact, a reactor of this design has never been built outside the old Soviet Union.
The operative practices of soviet reactors were not akin to those of Western countries, where they would have never been allowed.
Effects and studies
The effects of the Chernobyl accident have been evaluated by international organizations, fundamentally OIEA and the National Heatlth Organization. The results of their investigation have been made public, and are summarized as follows:
According to the report from the World Health Organization, “Chernobyl: the true scale of the accident”, that was made in mid-2005, less than 50 casualties can be directly attributed to the radiation released by the Chernobyl accident: most of the accident’s direct deaths took place among workers of emergency services who suffered an intense explosion and died a few months after the accident.
There is also a press release on IAEA.org.
This same report indicates that contamination from by the accident has caused around 4,000 cases of thyroid cancer, mainly on people who were children or adolescents at the time, and at least nine children have died of thyroid cancer; in all, the survival rate among cancer victims, according to the experience in Bielorussia, was almost 99%.
A total of 4,000 people could have died for reasons related to the radiation they were exposed to after the accident that happened at the Chernobyl nuclear power plant, according to conclusions from an international team integrated by over 100 scientists.
One of the greatest damages produced to the population was the psychological damaged derived from a lack of knowledge of the effect of radiation and the incorrect information that was given.
The ecosystems affected by the Chernobyl accident have been widely studied and observed in the past two decades. During the first ten days there were large emissions of radionucleids that contaminated over 200,000 square kilometers in Europe.
After the accident, the electric companies around the world that were proprietors of nuclear power plants founded The World Association of Nuclear Operators (WANO)
Closure
In December 2000 unit 3 was definitely shut down. It was the last unit that remained in operation. The Ucranian government constented to the shut down after reaching an economic agreement with Euratom, the Russian government and the European Bank for Reconstruction and Development in order to complete the construction of the nuclear reactors Khmelnitski 2 and Rovno 4. The electricity produced at these two sites is enough to satisfy the country’s energy demands. Reactors in Eastern Europe, including RMBK, have been improved with great help from the West.
After the accident, the electric companies around the world that were proprietors of nuclear power plants founded The World Association of Nuclear Operators (WANO), in order to reach the highest levels of safety and reliability in the operation of nuclear power plants, through the exchange of technical information, comparison, emulation and communication among its members.
In July 2007, by initiative of the European Comission, the High Level Group on Nuclear Safety and Waste Management was created to help the European Union to reach its goals in the nuclear field. Whereas the final decision to rely on this source of energy is up to each country, the question of nuclear safety and radioactive waste concerns all. This group shall be of help to the European Comission in developing European norms as regards safety at nuclear sites and the safe management of waste fuel.
Western countries have continued to set new units into operation after the Chernobyl accident, and additional programs of new nuclear power are under development mainly in Asian countries, where there is a large increase in demand for electric energy.
Could a nuclear accident like the one at Chernobyl ever happen again?
The accident at Chernobyl was caused by a series of circumstances that would be unrepeatable at Western nuclear sites. The lack of a safety culture, the lack of a regulatory body and the fact that political power prevailed over technological knowledge, ultimately led to the accident. We must also add to this that the RBMK reactor did not have a contentment enclosure, which would have contained radioactivity. The site’s design did not allow the recuperation of the reactor’s control in order to avoid the emission of radioactive products into the atmosphere. Additionally, this type of reactor would have never obtained operation authorization in Western countries. Ever since the accident, these types of reactors have either been completely shut off or improved thanks to the improvement programmes from the European Union (wherein the Spanish nuclear industry has also participated), the United States and Japan.
Chernobyl’s restoration program is financed by 29 countries that contribute to the Financial Fund for the Confinement of Chernobyl
The great sarcophagus at Chernobyl
The Ucranian Minister of Foreign Affairs announced in November 2011 that there were enough financial commitments to begin construction of the new sarcophagus that will cover the Chernobyl reactor, which suffered in 1986 the greatest nuclear accident in History.
Chernobyl’s restoration program is financed by 29 countries that contribute to the Financial Fund for the Confinement of Chernobyl, created in 1997 and administered by the European Bank of Reconstruction and Development. This financing will also make it possible to build a storage house for waste fuel from the other three units at Chernobyl, which in 2015 shall contain over 200,000 fuel elements.
Currently, a first stage has been completed for the construction of the new sarcophagus (called New Safe Contention, or NSC), which is to cover up the first sarcophagus, constructed quickly to contain the remainders of unit 4 after the 1986 accident.
This first stage, which sets the start of construction, involved the elevation of up to 22 meters of the upper arc of a first module, formed by the union of several narrower arches, and has been given hermetic covering, with a total weight of around 5,300 tons. When the module’s intermediate and lower sections are finished, they will be gradually be welded together, elevating the whole structure to a height of 108 meters. The complete module will be carried on a concrete trail until it faces the old sarcophagus.
The second module will be built following this, by the same procedure, and placed after the first. Previous to this, the necessary cranes and machinery will be placed in the area, for the dismantling and material removal, to be carried out afterwards via remote control from outside the new sarcophagus.
Lastly, both modules will be joined together over the previous sarcophagus using hydraulic jacks. And two closure walls will be placed as well.
The dimensions of the new Safe Contention, once it is built, will be 108 meters high, 257 meters wide and 150 meters long and weigh approximately 30,000 tons. The structure will be hermetic both to protect the inside from exterior atmospheric phenomena and to avoid the uncontrolled release of contaminated fuel and materials that are being manipulated for their disposal. The structure, however, is not designed as an armor, for which reason exterior operations must be executed with the necessary personal protection against gamma radiations.
The construction of NSC and installation of systems will be finished before the end of 2015. The entire system is designed to last over 100 years, and it is expected that total dismantling will be finished by then.
