Almost as soon as firefighters started pumping water into the reactor, it began flooding a basement room directly below. The basement contained the valves that controlled the coolant liquid that normally kept the reactor stable. But as the reactor rose to 2,000 degrees Fahrenheit, it began to melt the protective concrete floor below.
Experts feared that if the molten nuclear material came into contact with the water, it would unleash a gigantic steam explosion that would destroy the entire power plant, level Kyiv 60 miles away, and release so much radiation into the air that most of Eastern Europe would be uninhabitable for at least 100 years.
So on April 28, 1986, Ananenko, Bespalov, and Baranov volunteered to descend into the basement, locate the valves, and drain the tank. Protected only with diving suits and respirators while armed with a single flashlight, they waded through the radioactive water in near pitch-black darkness.
They entered Chernobyl via the reactor's chamber, standing in waist-high radioactive waters in total darkness. Baranov's diving light was reportedly dim and periodically flickering on and off. Every minute spent in the facility was another minute that isotopes freely ravaged their bodies. The light eventually burned out permanently, but not before they saw a familiar pipe that they knew led to the valves they were looking for. They grabbed the pipes and followed it until they found the two gate valves, which they twisted open to let the water out. The pool quickly began to drain.
Many news sources reported that all three men died within a few weeks due to radiation sickness. However, according to Andrew Leatherbarrow, author of the 2016 book "Chernobyl 01:23;40," Ananenko continues to work in the nuclear energy industry, and Bezpalov was also found to be alive. Baranov died in 2005 of heart failure at the age of 65.
It is believed that the water absorbed much more radiation than initially believed and ultimately saved their lives.
It took several days of many descents for them to find the valve and turn it enough to begin the draining process, and by May 8, a full 20,000 tons of water had been pumped out, sparing millions of lives from a nuclear winter.