OI, Fukui -- A low-water level alarm sounded at the Oi Nuclear Power Plant's No.4 reactor here on May 10, according to plant operator Kansai Electric Power Co.
The alarm indicating low water inside the unit's steam generator stopped immediately after it rang at 5:38 p.m. However, Kansai Electric took the reactor off-line to check the situation. The utility had just restarted the No.4 reactor on May 9.
Heat transmission tubes in the steam generator boil the reactor's water coolant into steam, which then spins the generator turbine. Kansai Electric believes that one of four water level indicators inside the steam generator malfunctioned, and stated that there were no problems affecting the environment.
The utility restarted the reactor again at 1:35 a.m. on May 11. ,
(Japanese original by Kazutaka Takahashi, Fukui Bureau)