Anatoly Dyatlov was the deputy chief engineer who supervised the test that lead to the explosion. At the moment the reactor power slipped to 30 MW, he insisted the operators continue the test. He overrode Akimov's and Toptunov's objections, threatening to hand the shift to Tregub (the previous shift operator who had remained on-site), intimidating them into attempting to increase the reactor power.

After the explosion, despite seeing the fuel and graphite scattered around, he still believed the reactor was intact. At 5 a.m., he got sick and together with Gorbachenko went to the medical unit.

After the disaster, Dyatlov was sentenced to 10 years in prison for his role in the explosion but he was released after serving 5. In 1995, he passed away from heart failure.