April 26 marks grim anniversary
By Natalya Yakusheva
On April 26, 1984, an explosion inside Reactor No. 4 occurred at the Chernobyl Nuclear Power Plant in the Ukrainian SSR (now Ukraine), causing what is to date the worst civilian nuclear accident in history. The 25th anniversary of this chilling accident takes place just six weeks after a major earthquake and tsunami swells laid siege to the Fukushima Nuclear Power Plant in Japan, raising fears of a 'new Chernobyl'. While it is too early to know the full extent of radioactive damage in the Japan, a quarter of a century has passed during which we can better understand the impact of the Ukrainian disaster.
So, what did happen?
The Reactor 4 explosion of April 26th happened after an attempt to maximise the reactor turbine's energy production efficiency. The test, however, was rescheduled to be conducted at night, as to not interrupt regional demand for electricity. The crew was not specially trained for this type of experimental effort; and furthermore, safety systems had been switched off deliberately - for no clearly ascertainable reason. This chain of human error led to a violent explosion in which the reactor's graphite ignited, and the ensuing fire burned continuously for nine days. The military arrived on April 27 to try to put out the fire, and a 'sarcophagus' was built quickly to contain the damaged reactor, though it was already too late to prevent the release of substantial amounts of radioactive material.
The accident produced two main contaminating substances. The first is radioactive iodine-131, with a half-life of 8 days. It largely disintegrated within first few weeks but is blamed for many cases of thyroid cancer to have emerged following the accident. The second substance is caesium-137, which has a half-life of about 30 years and will take several centuries to disappear. Moreover, this radionuclide is able to pass through and contaminate the food chain.
Wide data margins
Many of the health figures from the Chernobyl disaster are difficult to reconcile. On one hand are low-end estimates linking the accident directly with just 29 deaths (namely, clean-up workers). The aforementioned WHO analysis goes much further, linking Chernobyl-tainted milk to cases of thyroid cancer among those who were children or young adults and living in the most heavily contaminated areas of Belarus, Russia and Ukraine at the time of the accident. The WHO claims that nearly 5,000 cases of thyroid cancer have been diagnosed in these countries among people who were 18 years or younger at the time of the accident, and also points to a growth in the number of cases of leukemia, cataracts, cardiovascular disease and mental illness. Numbers and causal links, however, remain difficult or nearly impossible to verify. Greenpeace, meanwhile, conducted an alternative study based solely on national cancer statistics from Belarus. The numbers from this study are far more harrowing: 270,000 cancers and 93,000 fatal forms of the disease are attributed to the Chernobyl accident.
As for the affected area today, national and international scientists, politicians and energy analysts have shifted focus elsewhere. If the Fukushima disaster returns some focus back to Chernobyl, one can be certain that there is still plenty of remaining radioactive pollution to study.
In Ukraine, 18,000 square kilometres of agricultural land and approximately 40% of the country's woodlands were contaminated with radiation. For more than two decades following the accident, the Ukrainian Government conducted regular analyses of food produced in the contaminated areas. These reports contain important long-term data, but studies have not been performed in the past two years. It should be noted that the area affected by the Chernobyl accident is much wider than the current 'exclusion zone,' which is limited to just within 30 kilometres in each direction.
In March 2011, independent research conducted by a team of Greenpeace scientists showed that key foodstuffs produced in the study area are subject to contamination: 14 of every 15 milk samples (93%) contained levels of caesium-137 that were between 1.2 and 16.3 times the acceptable amount for children.
Whither nuclear power?
Of course, the world is now following events in Japan. When the crisis first unfolded, authorities insisted that the situation was under control, but on April 12 the Fukushima facility was categorised as posing a level-7 threat, according to the International Nuclear Event Scale (INES). Naturally, concern over Fukushima has rekindled heated debate over the safety and viability of nuclear technology. Many countries are revising energy strategies or putting existing plans for nuclear power plants on hold, while others appear to be taking a business-as-usual approach.
The strongest immediate opposition to continued use of and support for nuclear power took place in Germany, where more than 50,000 people participated in a chain of protest stretching from Stuttgart to the nearby Neckarwestheim facility. An estimated 100,000 people participated in demonstrations actions across the country, prompting Chancellor Angela Merkel - no doubt mindful of upcoming elections - to impose three-month moratorium on a reactor-lifespan extension passed in 2010. On the other hand, France, Europe's biggest user of nuclear energy, has declared the need for dialogue. Calling for an "open and transparent" audit, French President Nicolas Sarkozy argued nonetheless that nuclear energy provides energy security and reduced greenhouse gas emissions. In an even more visible show of support for the nuclear industry, US President Barack Obama publicly called for continued development of new US nuclear power facilities, even as events in Japan were still unfolding.
With a number of alternative, renewable energy sources available, and with modern technologies increasingly able to exploit their potential, the question remains as to whether long-term commitment to nuclear energy is worth the many, and perhaps incalculable, risks involved.
