Following the instruction to compile an investigative report in response to pipe thinning phenomena, issued by the Nuclear and Industrial Safety Agency on August 11, 2004, the Kansai Electric Power Co., Inc. (Kansai Electric) is now reviewing its inspection records.
The findings of our investigation to date are shown below.

The investigation has so far revealed that there was one section at the steam converter heating steam systems of each of Mihama Unit 3, Takahama Unit 1, and Ohi Units 3 & 4 (four sections in total) where wall thinning has not been monitored and evaluated.

At present, the only steam converter in operation is the one at Takahama Unit 1. Kansai Electric will stop operating the steam converter and isolate it to ensure safety.

The other three converters are not in operation now.

* The steam converter is part of the plant auxiliary system, which supplies steam to the air conditioner, helps heating tank water, etc., provides turbine gland steam during plant startup, and supplies steam to the seawater desalination unit. This system is not safetyrelated and so is not subject to operational restrictions imposed by the safety regulations. Therefore, plant operation would not be compromised at all even by shutting down the system.