By Julio Godoy
The ruins of the Chernobyl nuclear reactor where an explosion 25 years ago led to one of the worst environmental disasters in history still contain 95 percent of the original fuel load, which remains highly radioactive.
The aging sarcophagus built over the reactor is not airtight, and as a result, current radiation levels in Chernobyl, 100 kilometres north of the Ukrainian capital, Kiev, are 100 times greater than natural levels, according to recent measurements made by environmental experts.
“The radioactivity we measured in Chernobyl is coming from the nuclear plant. The sarcophagus over reactor number 4 has numerous holes and needs to be replaced as soon as possible,” Heinz Smital, a Greenpeace nuclear specialist, told Tierramérica.
Smital, who recently visited the area, said that a new enclosure has been under construction since late 2010. “But given the high level of radioactivity, which would have lethal effects in a very short time, it is impossible to work in the vicinity of the reactor, which means the new sarcophagus has to be built far from the site and then rolled to Chernobyl over rails,” he explained.
Apr. 26 will mark the 25th anniversary of the explosion. Numerous measurements indicate that the radiation absorbed in just six seconds on the site of the reactor is greater than the maximum annual amount permitted for nuclear power plant workers.
The new steel and concrete enclosure will weigh around 29,000 tons and cost 2.3 billion dollars, according to a new estimate released at a donors conference held in Kiev on Apr. 19.
The Ukrainian authorities had hoped to raise 1.1 billion dollars to finance the project, but donor pledges totalled just under 800 million.
The conference, organised by the Group of Eight industrial nations (G8) with the participation of the European Union, was held to discuss the financial needs for the new sarcophagus, which should have been completed in 2007, but it is now not expected to be ready until 2015 at the earliest.
The delay created by this lack of funds will translate into an even higher death toll from the nuclear disaster.
According to the study “Health Effects of Chernobyl: 25 years after the reactor catastrophe”, released this month by the German affiliate of International Physicians for the Prevention of Nuclear War (IPPNW), the disaster led to the death of at least 112,000 of the so-called “liquidators” or clean-up workers, soldiers and state employees who participated in containment efforts in the months following the explosion, including the construction of the first sarcophagus.
The IPPNW estimates that up to 90 percent of the 830,000 clean-up workers have developed some form of cancer. The Chernobyl disaster is also blamed for 5,000 deaths in other parts of Europe, as a result of the radioactive cloud that spread all over the continent, from Sweden and Finland in the north to Italy and Spain in the south.
Other studies document cases of cancer and genetic mutations in children born after the disaster. The World Health Organisation estimates that in Belarus alone there are over 50,000 children who suffer or will suffer from thyroid cancer. The United Nations Scientific Committee on the Effects of Atomic Radiation estimates that worldwide, between 30,000 and 207,500 children have been born with genetic defects as a result of the Chernobyl nuclear accident.
Although there are no definitive figures, Chernobyl may have caused the death of as many as 900,000 people across Europe.
Even the International Atomic Energy Agency, which approves of the civilian use of nuclear energy, reaches some alarming conclusions: while infant mortality in the Scandinavian countries rose by 15.8 percent as a result of Chernobyl, Germany experienced an increase in cases of Down’s syndrome and infant neuroblastoma, a cancerous tumour that forms from nervous tissue and is often fatal.
Oncologist Edmund Lengfelder, director of the Radiological Protection Institute in the southeastern German city of Munich, told Tierramérica that even today it is possible to detect high concentrations of caesium-137, a radioactive isotope, in wild mushrooms picked and animals hunted in German forests. The meat of a wild boar, for example, could easily surpass the maximum level of radioactivity permitted by the German Ministry of Health, 600 becquerels per kilogram,.
The Chernobyl accident occurred on Apr. 26, 1986 as the result of a systems test conducted by the power plant staff, which caused a sudden power surge and the overheating of reactor number 4. This in turn led to the explosion of the hydrogen accumulated inside, which blew the reactor’s roof 15 metres into the air.
The explosion released eight of the 190.2 tons of nuclear fuel contained in the reactor and spread them across Europe. The resulting radioactive cloud contained uranium dioxide, caesium-136, boron carbide and other materials, and was considered 500 times more toxic than the atomic bomb dropped by the United States on the Japanese city of Hiroshima in 1945.
The remaining 182 tons of fuel are still contained beneath the original sarcophagus built over the reactor, constituting a deadly radioactive magma that urgently needs to be fully contained.
“That is the goal of the new sarcophagus,” said engineer Hosni Bouzid, the director of the construction project commissioned by a consortium formed by the French companies Vinci and Bouygues.
“During the preparation work in 2010, we found all kinds of materials on the site, all of them contaminated, including cranes, the remains of helicopters and pieces of the scaffolding used 25 years ago to build the first sarcophagus,” he told Tierramérica.
Construction and installation of the new enclosure is a technical, environmental and health challenge, since it will mean eventually coming into contact with the Pandora’s box that Chernobyl continues to represent.