Japan’s Tepco To Restart Nuclear Reactor Monday After Alarm Issue

TOKYO, Feb 6 (Bernama-Kyodo) -- Tokyo Electric Power Company Holdings Inc. said Friday it will restart a reactor at a nuclear power plant in Niigata Prefecture, northwest of Tokyo, on Monday, after the facility was halted over an alarm incident, Kyodo News Agency reported.

TEPCO also revealed that the start date of commercial operations of the seven-unit Kashiwazaki-Kariwa plant has been pushed back to March 18 from the previously planned Feb 26, after the company determined that a setup error likely caused the alarm incident.

Last month, the utility brought its first nuclear unit back online since the 2011 Fukushima disaster, but the operation of the No. 6 reactor at the power plant located on the Sea of Japan coast was suspended after an alarm went off during control rod withdrawal about five hours and 25 minutes later.

With the alarm pointing to abnormalities in an inverter, which changes the frequency of electric current to manage the speed of a control rod, in the early hours of Jan 22, TEPCO replaced the parts suspected of having caused the problem, but the situation did not improve.

The utility stopped the reactor the following day and investigated the problem further.

According to the investigation, the inverter itself was not broken but the alarm was set to be too sensitive in detecting changes in electric current.

Following the restart of the reactor, TEPCO will conduct power generation and transmission on a trial basis, as well as facility check-ups while halting the reactor, and move to commercial operations if no problems are detected even if output is increased to near full capacity, the company said.

TEPCO, facing massive compensation costs and other expenses related to the 2011 nuclear accident, believes that restarting units at the complex, the world's largest nuclear power station by output when fully operational, will increase revenues and help it compensate those affected by the disaster.

-- BERNAMA-KYODO