TOKYO, Jan. 30 (Xinhua) -- A reactor at Kansai Electric Power Co.'s Takahama nuclear plant in Fukui Prefecture of central Japan was automatically halted Monday after an alert went off, local media reported.
Following an alert warning of a rapid decrease in the number of neutrons within the unit, the No. 4 reactor at the Takahama plant was halted at 3:21 p.m. local time, Kyodo News reported.
There has been no indication of the incident causing environmental contamination, said the report citing the complex's operator.
Japan's Nuclear Regulation Authority said the reactor's cooling function is normal, it added.
The No. 4 reactor restarted in November last year after being shut down for routine inspections.