The liquidators of Chernobyl

The immediate challenge, in the days following Chernobyl, was to extinguish the graphite still burning in the reactor: Soviet scientists had calculated that this fire had to be brought under control before May 8, otherwise there would be a thermal explosion likely to release a large quantity of radionuclides into the atmosphere.

Tens of thousands of workers were rushed to the site in order to build a sarcophagus in a hurry. The teams were exposed in shifts for periods of a few seconds to a few minutes to intense radioactivity, with orders to linger as little as possible. They had neither information on the risks involved nor effective protection; they tinkered at most with the kinds of armor with recovered materials and lead plates that they had been supplied with. A distribution of iodine pills was allegedly carried out among them, but it was not systematic and the order to take it was not always respected. Workers clearing materials from the plant and pilots flying over the site through the cloud of radioactive dust were particularly exposed.

   The total number of individuals from all over the USSR (power plant operators, firefighters, helicopter pilots, miners, diggers, workers, military or civilians) who took turns at the site between 1986 and 1992 is estimated at between 500,000 and 800,000. About 3,000 liquidators are still assigned to the surveillance of the site and the reactor sarcophagus.
   Part of their work was motivated by what was hailed as an act of dedication, even a real "sacrifice" (in the case of people aware of the danger), and more broadly by promises of high salaries and social benefits (housing, places in crèches...) or symbolic (medals and diplomas) awarded by the government. While the first responders were volunteers, most of the liquidators were later requisitioned.
   Some of these interveners were later declared "heroes of the Soviet Union". This was the case in particular of Nikolai Melnik, a helicopter pilot who had placed radiation sensors on the reactor2 , and Major Leonid Teliatnikov, responsible for firefighting, to whom a monument was erected posthumously at the Baykove cemetery in Kiev on 25 April 2006.

The liquidators assigned to collect the contaminated graphite blocks from the reactor roof were called "biological robots" or "green robots" or "bio-robots", the name "roof cats" or "Krycnye Koty" referring to the dosimetrists who mapped the "hot" areas. It was under these conditions that the fire was finally brought under control on May 6, 1986.