A precondition for the creation of WANO was the accident at the Chernobyl nuclear power plant in 1986. In addition to immediate consequences, the accident received an echo in the entire nuclear power industry as a whole. It forced the operators to overestimate the safety of the nuclear power plant and to think about the need for international cooperation. A nuclear accident in any region can have consequences for other countries; therefore, all operators of nuclear power plants bear a collective responsibility for ensuring the reliability and safety of their operation. WANO was created after the Chernobyl accident by NPP operators around the world, who tried to do everything possible to prevent the recurrence of such an accident. The official formation of WANO was proclaimed at the constituent assembly on May 15, 1989 in Moscow.