The Nuclear Regulation Authority said Wednesday it will prohibit its staff from meeting alone with officials of atomic power plant operators even if it is a courtesy visit, to ensure transparency in its dealings with the industry.

The decision was reached after the NRA recently discovered that a senior official of its secretariat had given an undisclosed document to officials of Japan Atomic Power Co. during a meeting at which no other members of the regulatory body attended because it was held under the guise of a "courtesy call."

The incident has been taken seriously inside the NRA as part of efforts to bring an end to collusion between regulators and plant operators.