Tokyo Electric Power Company Holdings has fixed a malfunction in a measuring instrument at the No. 6 reactor of its Kashiwazaki-Kariwa nuclear power plant by replacing parts. The glitch is expected to delay the planned start of power generation and transmission from Monday afternoon by about half a day.
Tokyo Electric Power Company Holdings (TEPCO) announced on February 15 that it has resolved a malfunction in a measuring instrument at the No. 6 reactor of its Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture by replacing parts. The plant is one of Japan's largest nuclear facilities.
As part of the restart process, TEPCO temporarily halted the reactor to inspect the inside of the containment vessel. No other abnormalities were detected, and the reactor was restarted on Saturday evening. The malfunction occurred in an auxiliary instrument of a neutron detector that monitors conditions inside the reactor, which had been restarted in January for the first time in 13 years and 10 months.
On Thursday evening, while the instrument was being electrically moved in and out within the containment vessel, it failed to operate normally. A faulty connection was identified in the switch that operates the instrument. Following the replacement of parts, the instrument began functioning normally.
TEPCO plans to halt the reactor again on Friday, after power generation and transmission begin, to inspect turbine-related equipment and other systems for any abnormalities. A final inspection is scheduled for March 18. Upon confirmation by the Nuclear Regulation Authority, the reactor is expected to commence commercial operation.
This incident highlights ongoing efforts to meet stringent safety standards post the Fukushima Daiichi accident.
