First firemen at Chernobyl site were exposed to 5,600 years-worth of radiation in 48 seconds
The accident at reactor no. 4 at the Chernobyl Nuclear Power Plant, near the now-abandoned town of Pripyat, in Northern Soviet Ukraine, on 25th and 26th of April 1986, remains the worst nuclear disaster in human history.
A combination of design flaws and operators arranging the core in a manner contrary to a safety checklist which simulated a station blackout power-failure led to uncontrolled reaction conditions that resulted in a destructive steam explosion which saw plumes of radioactive material released into the atmosphere.
The radioactive material precipitated onto parts of Western USSR and other European countries, with officials declaring a 30 km area extending in all directions from the plant as a 'zone of alienation' or 'the exclusion zone.'
Even today, more than 30 years after the accident, radiation levels are so high that workers responsible for rebuilding the 'sarcophagus' — the term designated to the massive steel and concrete structure used to cover the radioactive remains of reactor no. 4 —are only allowed to work five hours a day for one month before being forced to take 15 days of rest. Ukrainian officials estimate that the area will not be safe for human life for at least another 20,000 years.
So, one can only imagine how fatal the radiation must have been on the night of the disaster. Anatoli Zakharov, a fireman who had been stationed in Chernobyl since 1980, was called into action that fateful night and would see several of his peers succumb after exposure to near-unthinkable levels of radiation.
Because the hot debris from the reactor had set fire to the bitumen-covered roofs of surrounding buildings, there was a very real threat of the fire catastrophically spreading to reactor no. 3. To prevent such a scenario, Zakharov's lieutenant and a few other officers climbed a ladder to the roof to fight the fire. It would be the last time he saw them alive.
They had no protective clothing or dosimetric equipment to measure levels of radiation and the firefighters picked up blazing radioactive debris fused with molten bitumen with their hands so they could chuck it away.
After they managed to successfully control the fire, they proceeding to climb into the ruins of the reactor hall, where graphite was burning at temperatures more than 2,000-degree Celcius. The move put them closer to a lethal source of radiation than even those who perished in the Hiroshima bombings.
On the roof of the turbine hall, they had been exposed to lumps of Uranium and graphite which were emitting gamma and neutron radiation at a rate of 20,000 roentgen per hour. Around the core, that rate was 30,000 roentgen per hour. And yet, Zakharov's lieutenant and his men were relieved from their duties at the site only after they had already been there for an hour.
To put into context how lethal that is, a fatal dose of radiation is estimated at around 400 rem (rem, or roentgen equivalent man, is a measure of the health effect of low levels of ionizing radiation on the human body). A total of 400 rem would be absorbed by anyone whose body is exposed to a field of 400 roentgen for 60 minutes. On the roof and the reactor room, the firefighters would have absorbed the fatal dose in just 48 seconds. Standing there for an hour would have exposed them to a dose equivalent of 5600 years of allowed dosage.
When they died two weeks later, their bodies were still so radioactive that they had to be buried in coffins made of lead, with the lids welded shut to prevent any chance of latent radiation seeping through the cracks.
The radiation levels were not any better for those tasked with cleaning up the power plant in the immediate aftermath of the accident either. Considered the greatest clean-up operation in the history of mankind, the term 'liquidator' was coined for workers who entered the areas ruled to be "contaminated" between 1986 and 1989.
While estimates widely vary, the number of liquidators involved is believed to be anywhere between 300,000 to 350,000, though a report by the Nuclear Energy Agency puts the number as high as 800,000. It's not that these liquidators were all radiation experts either. While the group included power plant operators, it also included firefighters, military personnel, and many non-professionals, each of whom was tasked with work ranging from cleaning up the debris around the reactor, to decontamination, to even road building.
Information regarding the dangers of their tasks was often unknown or suppressed. The number of liquidators who died as a consequence of their involvement in the clean-up is still unclear, with different agencies quoting different figures. But the telling figure comes from Vyacheslav Grishin of the Chernobyl Union, the main organization of liquidators, who claimed as many as 60,000 has died and that another 165,000 were left disabled.
HBO's upcoming historical drama miniseries, 'Chernobyl', is set to tell "the true story of one of the worst man-made catastrophes in history and the brave men and women who sacrificed to save Europe from unimaginable disaster." Slated for release on May 6, it seems all but certain that liquidators such as Zakharov will feature prominently in the series.