We found minute steam leak at about 7:00 pm on March 30, 2018 from an air-bleeder pipe of deaerator in secondary system of Genkai Nuclear Power Station Unit No.3 (Pressurized Water Reactor, 1,180MW output), which has been in periodic inspection. The plant, which restarted to generate electricity on March 25, 2018, had been in adjustment operation with output of 75%.

　As a result, we decided to stop generating by dropping a load from output of 75% and to investigate the plant as a precaution.
　There is no effect of radiation to the environment on this matter.(Already announced on March 30, 2018)

【Status on April 2】

　As a result of investigating the air-bleeder pipe of deaerator, we found a dent on a part of external surface of the pipe, and a hole on the dent part as well as adherence of substances such as discoloration and rust inside the heat insulating material.

　We presumed that the pipe is installed outdoors so that the heat insulating material got wet because of ingress of rainwater from the gap of the exterior board covering the heat insulating material, then the external surface of the pipe corroded, and the hole might be made.

　As a countermeasure, we will take measures for rainwater prevention thoroughly, and replace the pipe, the exterior board and the heat insulating material.

　In addition, regarding the remaining fifteen air-bleeder pipes other than the said pipe, we will also take measures for rainwater prevention thoroughly, and replace pipes, exterior boards and heat insulating materials as well.