Photo credit: Air Photo Service/AFP/Getty Images
By David Robert Grimes
This year marks the fifth anniversary of the Fukushima disaster, and the 30th anniversary of the Chernobyl incident. Together, these constitute the two greatest nuclear accidents the world has ever seen.
Even now, widespread confusion over these disasters still blights rational discussion on energy production; too often the debate becomes needlessly acrimonious, reliant on rhetoric in lieu of facts. Yet as climate change becomes an ever-encroaching factor, we need more than ever to have a reasoned discussion on nuclear power. To this end, it’s worth dispelling some persistent myths.
The events in the Ukrainian town of Pripyat on the morning of 26 April 1986 have permanently etched the name Chernobyl, and all its connotations, into the public mind. With a dark irony, it was a poorly conducted safety experiment that was the catalyst for the worst nuclear disaster in history. The full odious sequence of events that led to the accident would constitute an entire article. In essence, however, the mixture of flawed design, disabled redundancies and a tragic disregard for experimental protocol all feature heavily in the blueprint of the disaster. The net result of this errant test was a massive steam explosion, replete with enough kick to blow the 2,000 ton reactor casting clean through the roof of the reactor building.
Despite the sheer explosive force of the eruption, what ensued was not a nuclear blast. The spectre of the cold war has left an unfortunate conflation between nuclear weapons and nuclear power, but it is important to note that they operate on very different principles. The Chernobyl explosion was instead a conventional high-pressure failure due to excess steam. Seconds later, the remaining coolant flashed to steam and a second even greater explosion occurred, dispersing the shattered nuclear core and effectively terminating the chain reaction. This second explosion also ejected chunks of graphite moderator into the air, which caught fire, releasing radioactive fallout. It’s estimated that the second explosion released 40bn joules of energy – roughly equivalent to a staggering 10 tons of TNT.
Contrary to all safety regulations, the roof of the reactor complex had been constructed with bitumen, which proved a highly flammable agent. The burning, highly toxic graphite rods ignited at least five fires on the roof of the adjacent reactor. To compound matters further, the night shift and engineering chief squabbled over whether the reactor should be shut downFor several hours workers were in situ with minimal protection. Firefighters arrived on the scene, completely unaware of the dangers they were being exposed to. In the commotion, a helicopter tasked with dumping 5,000 metric tons of sand and neutron-absorbing boron in an effort to quench the flames collided with a crane and spiralled into the ground, killing all four of crew members immediately – a tragic event caught on camera. By 5am the fire had been brought under control, but a number of men had been exposed to high radiation levels and lacked even the most basic protection.
The Soviet response was an unmitigated disaster; rather than admit the fault and take preventative action, the authorities pretended nothing was amiss. In this interim of inaction, hazardous material released in the blast seeped unimpeded into the soil around Pripyat, chief among them radio-iodine 131. This radio-isotope has a half-life of a mere eight days, but if ingested it can accumulate in the thyroid, leading to illness and the potential emergence of thyroid cancer in later life. To circumvent this, those exposed to high levels of radio-iodine are generally given potassium iodide to prevent ill effect. But even this basic prophylactic response was not taken, and residents continued to ingest contaminated food. Finally, a full 36 hours after the explosion, the authorities gave the order to evacuate. This too was likely to have been covered up, had traces of radioactive fallout not been detected at a Swedish nuclear facility the next day, which revealed the scale of the problem to the world.
Chernobyl was a perfect storm, a damning tale of ineptitude leading to needless loss of life. It was also unequivocally the world’s worst nuclear accident. To many, it is also heralded as proof-positive that nuclear energy was inherently unsafe, a narrative adopted by many anti-nuclear groups. The word Chernobyl became synonymous with death on a massive scale. But perception and reality do not always neatly align; in the wake of the disaster, the UN Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and others undertook a co-ordinated effort to follow up on health effects. In 2006, after two decades of monitoring they outlined the health effects; of the firefighters exposed to the huge core doses and incredibly toxic smoke, 28 died from acute radiation sickness. A further 15 perished from thyroid cancer. Despite aggressive monitoring for three decades, there has been no significant increase in solid tumours or delayed health effects, even in the hundreds of thousands of minimally protected cleanup workers who helped purge the site after the accident. In the words of the 2008 UNSCEAR report: “There is no scientific evidence of increases in overall cancer incidence or mortality rates or in rates of non-malignant disorders that could be related to radiation exposure.
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